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Full text of "A treatise on earthy and other minerals and mining"

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STtlBRIS 




EARTHY AND OTHER MINERALS 
AND MINING 




WORKS BY THE SAME AUTHOR. 



A TREATISE ON METALLIFEROUS 

MINERALS AND MINING, Illustrated with numerous 
Wood Engravings. Second Edition, revised. Crown 8vo, 
i2s. 6d. cloth. (Uniform with, and forming a companion volume 
to, " A Treatise on Earthy and other Minerals and Mining.") 

"Without question, the most exhaustive and the most practically use- 
ful work we have seen ; the amount of information given is enormous, 
and it is given concisely and intelligibly." Mining Journal. 

" The author has gathered together from all available sources a vast 
amount of really useful information. As a history of the present state of 
mining throughout the world this book has a real value, and it supplies 
an actual want, for no such information has hitherto been brought toge- 
ther within such limited space." Athen&um. 

" The volume is one which no student of Mineralogy should be with- 
out." Colliery Guardian. 

A TREATISE ON SLATE AND SLATE 

QUARRYING, SCIENTIFIC, PRACTICAL, AND COM- 
MERCIAL. Illustrated with numerous Wood Engravings and 
Folding Plates. Second Edition, revised. i2mo, 33. 6d. cloth. 

"Mr. Davies-has written a useful and practical handbook on an impor- 
tant industry, with all the conditions of which he appears familiar." 
Engineering. 

"One of the best and best-balanced treatises on a special subject, 
having at once scientific, practical, and commercial relations, that we 
have met with." Engineer. 



CROSBY LOCKWOOD AND CO., 
7, STATIONERS' HALL COURT, LONDON, E.C. 



A TREATISE ON 



EARTHY AND OTHER MINERALS 



AND MINING" 



BY 



D. C. DAVIES, F.G.S. 



MINING ENGINEER; AUTHOR OF "A TREATISE ON SLATE AND SLATE QUARRYING," "A 
TREATISE ON METALLIFEROUS MINERALS AND MINING*" 

ETC., ETC. 





LONDON 
CROSBY LOCKWOOD & CO. 

7, STATIONERS' HALL COURT, LUDGATE HILL 

1884 
[All rights reserved] 




LONDON : 

PRINTED BY J. S. VIRTUE AND CO., LIMITED, 
CITY ROAD. 



V 

UNIVERSITY 




PREFACE. 



THE design of this book is to give such a full and intelligible 
an account of the minerals selected for description in it as 
shall be useful and interesting to persons engaged in mining 
pursuits, and in the manufacture of the substances described ; 
while it is also hoped that it will possess some interest for the 
general reader. It does not aspire to be a manual of miner- 
alogy, although it is hoped that the classified list of minerals, 
with a brief description of each species, given at the end of 
the book, will serve to show the mineralogical position of each 
mineral described, and form an introduction, for the student 
who may desire it, to the more elaborate and systematic trea- 
tises on mineralogy. It is intended as a companion volume 
to my work on " Metalliferous Minerals and Mining," and 
perhaps, in point of time, it should have preceded that 
volume. 

It will be observed that in the present book the distinctively 
earthy minerals are first considered. Next come those minerals 
which are compounds of earths and alkalies, some of which 
have a metallic base ; after which carbon and compounds of 
carbon are noticed. Sulphur next occupies a place by itself, 



vi PREFACE. 

and then follow a number of metallic minerals distinguished by 
the extreme difficulty with which their metals have been ex- 
tracted from them, and the rapidity with which those metals, 
when so obtained, and when unalloyed with others, unite with 
oxygen. 

The student is thus led up to the series of useful and noble 
metals described in the volume on " Metalliferous Minerals 
and Mining." In both volumes prominence is given to the 
way in which the minerals described occur in the strata of the 
earth. 

Of necessity a work of this kind must to a large extent be 
a compilation. It may, however, be permitted to me to say 
that a considerable portion of the information it contains is 
the result of my own observation and experience in the course 
of mining travels and work at home and abroad. I have 
thus been able to supplement the researches of others by my 
own. 

My hope is that the work which is the outcome of these 
combined researches may prove a useful one, and, with its 
companion volume, be found of permanent value for informa- 
tion and reference. 

D. C. DAVIES. 

EBNAL LODGE, GOBOWEN, OSWESTRY, 
April i$th, 1884. 



CONTENTS. 



PART I. EARTHY MINERALS. 



CHAPTER I. 

SILICA AND SOME OF ITS COMBINATIONS. 

PAGE 

Silicon Oxygen Silica Description Proportions in Rock Masses 
Redeposited Silica in Cavities, Cracks, and Beds Daubree's 
Experiments on the Decomposition and Crystallisation of Varie- 
ties of Quartz, Vitreous, Chalcedonic, Jaspery Rock Crystal and 
its Varieties Chalcedony Agates Flint Chert Jasper Opal 
Analyses of Rocks containing much Silica and Alumina . . 3 



CHAPTER II. 

ALUMINA, MAGNESIA, LIME, WITH SOME OF THEIR 
COM BIN A TIONS. 

Aluminium Alumina Bauxite Valued Forms of Alumina Corun- 
dum Sapphire Ruby Topaz Brazilian Deposits of Emerald 
Analyses of Beryl Emerald Mines of Grenada Tourmaline The 
Precious Stone Deposits of Ceylon More Massive Forms of 
Silica and Alumina Orthoclase Adularia Felspar Mica 
Magnesia Magnesium Talc Steatite Chlorite Serpentine 
Pyroxene Asbestos Rock Masses Granites and Gneiss Rocks 
Syenitic and Dioritic Greenstones Slaty Building Stones 
Liverpool Corporation Quarry, Llanwddyn Felspathic Rocks of 
North Wales Lime and Limestones Varieties of Costs of work- 



Vlll CONTENTS. 

PAGE 

ing Glucina, Zerconia, Thoria Chemical Composition of various 
Limestones 16 

CHAPTER III. 

CLA YS. 

Clays, how derived and formed Decomposition of Basalt, of Rocks 
in Iceland Brick Clays of the Drift Analyses Clays of the 
Tertiary Strata, Bovey Tracey China Stone and China Clay of 
Cornwall and Devon Comparison with other China Clays 
Kimmeridge Clay Permian Marls and Clays Clays of the Coal- 
measures Analyses Manufactures of, in North of England, 
North Wales, Shropshire Colouring of Clays and their Products. 38 



PART II. HALOID MINERALS. 



CHAPTER IV. 

SODIUM, CHLORINE, CHLORIDE OF SODIUM 
(COMMON SALT). 

Description of Sodium Of Chlorine Common Salt resulting from 
the Combination of the Two The New Red Sandstone Plains of 
England Stratigraphical Position of the Cheshire Salt Deposits 
History of Salt- working in Cheshire and Worcestershire Strata 
overlying the Cheshire Salt Beds Analysis of Rock Salt Of 
Brines Details of Cheshire Salt-mining Brine Springs of 
Worcestershire Associated Strata Detailed Section of Charac- 
teristics of the Brine Statistics Brine Springs of Ashby Wolds 
Salt Manufacture in the North of England Manufacture of 
Sulphate of Soda Discovery of a Bed of Rock Salt at Middles- 
borough Detailed Section of Strata Analysis of the Rock Salt 
Second Boring near Fort Clarence, with Results Rock Salt 
Deposits of Carrickfergus, Ireland Method of Working . .61 

CHAPTER V. 
CHLORIDE OF SODIUM continued. 

Salt Deposits of France, of Switzerland, of Spain The Salt Mines 
of Cardona, on the Ebro, near Burgos The Sea Salt Gardens of 
the South-west Coast Analyses of Sea-water Salt Deposits of 



CONTENTS. IX 

PAGE 

Italy, of Germany, Mecklenburg- Schwerin, Hanover, Anhalt, 
Wiirtemburg, Bavaria Salt Deposits of Austria, Salzburg, 
Wieliezka Description of the latter Mine The Sea Salt Gardens 
of Istria and Dalmatia Salt Mines of Roumania, of Russia, 
Solikamsk, Tchapatchi, Orenburg Salt Lake in the Crimea Salt 
Deposits of Africa, of Asia, Caspian Sea, Palestine Chemical 
Composition of the Water of the Dead Sea The Salt Deposits of 
Persia, of India Bahadur Khel Table of Strata Kohat Salt 
Range North America "Licks" of Michigan Petit Anse 
Island, Louisiana Nevada, Salt Lake of Dr. Chas. Darwin's 
Description of a Saline in Patagonia Inferences and Conclusions . 8 1 

CHAPTER VI. 

NITRATE OF SODA, BORAX, BARYTA, GYPSUM, 
FLUOR SPAR, AND ALUM SHALE. 

Composition of Nitrate of Soda Occurrence in German Salt Mines 
Deposits of in Peru and Chili The Desert of Atacama Statistics 
of Production Boron Boracic Acid Composition of the Lagoons 
of Tuscany Borax The Tincal Trade of Thibet Borax in Nepaul, 
in Iceland, and in Nevada Barium Baryta Sulphate Carbo- 
nate Sulphate of Baryta in Snailbeach Lead Mine The Wother- 
ton Barytes Mine, Shropshire Statistics of Production Gypsum, 
its Composition and Varieties Geological Position Statistics of 
Production Fluor Spar in Derbyshire and in Devonshire Native 
Alum Alum Shale Alum Industry on the Yorkshire Coast 
Description of the Deposits 100 

CHAPTER VII. 
PHOSPHATE OF LIME. 

Phosphorus Importance in Vegetable and Animal Life Use in 
Agriculture Mode of Occurrence in Nature Phosphoric Acid 
Apatite Other Forms of Phosphate of Lime Professor Henslow 
and the Coprolites of Suffolk Modes in which Phosphate of Lime 
occurs in Nature The Apatite Deposits of the Laurentian Rocks 
of Canada Their Range and Manner of Occurrence Particular 
Examples Analyses Particulars of Mining The Apatite or 
Phosphate Deposits of Norway Range Geological Age 
Various Modes of Occurrence Particular Examples Rutile 
Rock Dykes Analyses Difficulties of Dressing Mining Parti- 
culars . ^ _ . . . * * . . - . . 109 



X CONTENTS. 

CHAPTER VIII. 
PHOSPHATE OF LIME continued. 

PAGE 

Phosphatic Matter in Strata between the Laurentian and Lower Silu- 
rian The Phosphorite Deposit of North Wales Discovery 
Range Associated Strata Description of Bed Supposed Origin 
and Analyses Compared with ether Phosphates Particulars and 
Costs of Mining and Dressing The Phosphatic Deposits of Estra- 
madura, Spain Position Discovery Composition Description 
of Particular Deposits Deposits in Canada, France, Hungary 
Bone Bed at Top of Upper Silurian Strata in Shrophire . .129 

CHAPTER IX. 
PHOSPHATE OF LIME continued. 

The Greensand and Gault Position of Bedfordshire and Cambridge 
Phosphate Beds Localities Description of Beds with Fossil Con- 
tents Analyses Composition of the Phosphate Bed Derivation 
of the Phosphate Matter The Phosphatic Nodules of Suffolk 
Conditions of taking Phosphate Lands Phosphate Digging 
Statistics of Production Phosphatic Deposits of the Ardennes 
and the Meuse in France and Belgium Date of Discovery 
Geological Position Extent Characteristics of the Deposits 
Phosphate Deposits of Bellegarde, France Geological Position 
and Fossil and Mineral Characteristics Analyses Phosphatic 
Deposits of the Cretaceous Strata of Russia History of the Dis- 
covery of Mineralogical Features Analyses 146 

CHAPTER X. 

PHOSPHATE OF LIME continued. 

Phosphate of Lime in Tertiary Strata Phosphatic Deposits of Nassau, 
North Germany Situation Geological Structure of the District 
Illustrations of Modes of Occurrence Whence derived Analyses 
Phosphates of Tarn-et-Garonne, France Growth of the Industry 
Geological Position Modes of Occurrence Similaiity to the 
German Deposits Analyses Phosphatic Deposits of Carolina, 
America History of the Discovery of Geological Position 
Characteristics Land and River Phosphates Analyses Recent 
Phosphates Alta Vela Aruba Island Navassa Island Pedro 
Keys Redonda Island Sombrero Island St. Martin's Island . 160 



CONTENTS. XI 



PART III. CARBON, COMPOUNDS OF 
CARBON, AND SULPHUR. 



CHAPTER XL 
CARBON AND CARBONACEOUS SUBSTANCES. 

PAGE 

The Diamond History of Attempts to consume it, by Boordt, Boyle, 
Cosmo III., Sir Isaac Newton, Sir George Mackenzie, and Sir 
Humphrey Davy Diamonds of India, of Brazil, of South Africa 
History of the Discovery and Progress of the Industry and Parti- 
culars of Mining Notable Diamonds Plumbago or Graphite of 
Borrowdale, of Ayrshire, of North Wales, of Ceylon Particulars 
of Production in Ceylon Graphite in America Uses for which 
it is employed Jet Origin of Name Jet Industry of Yorkshire . 183 



CHAPTER XII. 

CARBON continued. 

Asphaltum, Varieties of History of the Uses of Bituminous Sub- 
stances Of the American Petroleum Industry The Cannels of 
Flintshire and Lancashire Modes of Occurrence The Torbane 
Hill Mineral The Bituminous Deposit of Bovey Tracey Deposits 
of Bituminous Matter in Silurian Strata in Ireland Bitumen in 
France Gneiss in Sweden Bitumen Deposits of France 
Asphalte of the South of France Bituminous and Petroleum 
Deposits of Germany The Hanover Oil-well Region . . . 204 



CHAPTER XIII. 

CARBON continued. 

Bituminous Deposits of Spain, Italy, Roumania Bitumen and Petro- 
leum of the Caucasus and Caspian Regions Bituminous Springs 
of the Valley of the Euphrates, of British Burmah, of the Punjab 
Pitch Lake of Trinidad Bituminous Springs of Barbadoes, 
Cuba, Venezuela Bituminous Coal Deposits of North America 
Geological Age of the various Petroleum-yielding Strata of North 
America Particulars of the Oil Mode of Sinking Wells Bitu- 
minous Springs and Schists of South America General Conclu- 
sions . . . 219 



Xll CONTENTS. 

CHAPTER XIV. 
SULPHUR. 

PAGE 

Abundance of Sulphur in Nature Varieties Sulphur Mines of Sicily 
Situation Geological Position Details of Strata Thickness 
of Sulphur Beds Percentage of Sulphur contained Associated 
Minerals Methods of Working Costs Sulphur Mines of the 
Mainland of Italy Cessena Geological Position Thickness of 
Bed Modes of Working and of the Treatment of the Mineral 
Sulphur Deposits of Greece, of Russia, of Iceland PYRITES, 
Production of in the British Isles Growth of the Treatment of 
on the Tyne Pyrites of Norway, of Germany, of Spain and Por- 
tugal Description of the Rio Tinto Mines of Spain . . . 232 



PART IV. METALLIC MINERALS. 



CHAPTER XV. 

ARSENIC. 

Arsenic, Native Orpiment, Realgar, Mispickel Production of 
Arsenic in the British Islands Modes of Treating the Ores in 
Cornwall and Devon and in Bohemia Mispickel of Norway and 
Sweden, of France, of Germany, of Austria, Transylvania, and 
Hungary, of Russia, Spain, Turkey, China, and of North and 
South America 253 

CHAPTER XVI. 
COBALT. 

Cobalt, Origin of Name Description of its various Ores Commercial 
Varieties Cobalt in the British Islands Cornwall North Wales 
The Foel Hiraeddog Mine Norway Skuterud Mine Indica- 
tions about Kongsberg and Drammen Sweden Mining District, 
from Nykoping to Westervik The Cobalt Mines of Tunaberg, of 
Gladhammar Processes employed at the latter Mine for the Extrac- 
tion of Cobalt from the Ores Mines of Hvena Germany, Riegels- 
dorf, Annaberg and Schneeberg Austria, Joachimsthal Past 
Production of Cobalt in Bohemia Spain Mine in the Pyrenees, 
France America Imports into England Suggestions . . 258 



CONTENTS. Xiii 

CHAPTER XVII. 

MOL YBDENUM ANTIMONY. 

PAGE 

Molybdenum, description of its Ores Commercial Uses British 
Islands : Inverness-shire, Charnwood Forest, Calbeck Fell Nor- 
way : Arendal, Numedal Sweden : Description of the Deposits 
of Ekholmen, on the Baltic Coast Germany Austria Hungary 
America Antimony, Early Knowledge and Uses of Story of 
the Origin of its Present Name Native Antimony Ores of Anti- 
mony Uses of the Mineral Antimony in the British Islands 
Cornwall Sweden : Sala Mine, Ofverrud Mine, Gladhammar 
Mines Germany: Hartz and Erzgebirge Austro-Hungary 
Borneo Algeria America New South Wales .... 272 

CHAPTER XVIII. 

MANGANESE. 

Manganese in its Native State Rapid Oxidisation of Uses of the 
Ores of Manganese Alloys of the Metal with Iron and Copper 
Description of its Ores Manganese Ores of Great Britain and 
Ireland Cambrian Rocks of North Wales, of Scotland Silurian 
Strata of Ireland, of North Wales Silurian and Devonian Strata 
of Cornwall and Devon History of Manganese Mining in those 
Counties Devonian Strata of North Wales Carboniferous Lime- 
stone of Derbyshire, of Shropshire The Manganese Deposits of 
Nassau, North Germany Italy : Mines of Val d'Aosta and Tour- 
nanche Spain : Mines of the Huelva District, of Cape de Gata 
France : the Roman eche Mines, Cevennes, Vosges Occurrence 
of Manganese in the Mines d'Asprieres America : Manganese 
Ores of Missouri, Arizona, Canada Inferences ^ * 282 

CHAPTER XIX. 
CLASSIFIED LIST OF MINERAL SUBSTANCES. 

Purposes of the Chapter Abbreviations List of Simple Elements, 
divided into Metallic and Non-metallic Further divided into 
Seven Classes Oxygen Enumeration of Classes with Included 
Substances Table of Strata Conclusion . ". \' . \ 39 



LIST OF ILLUSTRATIONS. 



FIG. PAGE 

1. Common Crystals of Quartz . 4 

2. Section of Folded Agate . ' . '". .' .* > . . 10 

3. Perspective View of Folded Agate . . . . .10 

4. Common Crystal of Corundum .'.**. . . ."".. 18 

/ /Crystals of Carbonate of Lime . . 32 

7. General Section across the Plain of Cheshire and Shropshire, 

showing the position of the Salt Deposits 62 

8. General View of the Peckforton Hills, Cheshire ... 70 

9. Section of Strata at the Wieliezka Salt Mines, Austrian Poland 87 

10. Section through Bahadur Khel Salt Locality, Trans-Indus Salt 

Region, India . . . 92 

11. Hill of Sal tat Bahadur Khel '. 95 

12. Order of Lauren tian Strata, Canada . . . . . . 112 

13. Map showing Position of the Canadian Phosphorite Deposits . 114 

14. Map of the Apatite District, Norway 120 

15. Section showing General Order of the Strata in the Apatite Dis- 

trict, Norway . 12 1 

1 6. Veins of Apatite at Tvitrae, Norway 121 

17. Apatite Veins, Godfield, Norway 121 

18. Section of Double Apatite Lode, Godfield, Norway . . . 122 

19. Section of Vuggens Apatite Mine near Kragero, Norway . .123 

20. Sketch of Rich Part of Apatite Lode, showing Pockets of Apa- 

tite with Hornblende 124 

21. Section of Apatite Deposit at Oedegaarden, Norway . . 125 

22. Fine Crystals of Apatite in Vuggens Mine, Kragero, Norway . 125 

23. Hill-side with Apatite Deposits at Doredalen, Norway . .126 

24. Section of Apatite Deposits at Midbo, Norway . . . . 127 

25. Map of Position of Bala Limestone with Phosphorite Bed, North 

Wales 130 

26. Section across the Berwyn Mountains 131 

27. Section of Strata at the Berwyn Phosphorite Mine . . . 133 



LIST OF ILLUSTRATIONS. XV 

FIG. PAGE 

28.] 

29. (Sections of the North Wales Phosphorite Bed with the associ- 
ated Strata 136-7 



30. ( 

3*. J 



32. Section of Strata at Green Hall Park, Llanfyllin . . .138 

33. Section of Strata at Cwm-dynewydd, Llanymawddy . . . 138 

34. General Section of Strata from the Summit of the Oolite upwards, 

showing the Positions of various Phosphate Deposits . . 147 

35. Section of Phosphate Bed on Sandy Heath, Bedfordshire . . 148 

36. Section illustrative of the Geological Structure of Nassau . . 161 

37. Section showing Phosphorite in Dislocation of Strata near Staffel 162 

38. Section at Cubach, showing Phosphorite and Manganese resting 

in Hollows of the Limestone 162 

39. Section of Phosphorite near Arfurt 163 

40. Section of Phosphorite Working in Opheim, near Limburg . . 164 

41. Section of Phosphatic and Associated Strata, Tarn -et- Garonne, 

France 168 

' > Sections of Phosphatic Deposits, South Carolina . . . 173-4 

44-] 

I?' iFigures of the Usual Forms of Diamonds i#3 

47- j 

48. ) Plan and Section of the Plumbago or Blacklead Mine, Borrow- 

49. / dale, Cumberland 193 

50. Section of the Blacklead Mountain, Ticonderoga, New York . 199 

51. Section of Yard Coal, Flintshire, showing Position of Cannel . 208 

52. Section showing the Position of the Torbane Hill Mineral . 210 

53. Section at Millaberg, Wermland, Sweden 213 

54. Section of the Oil-bearing Strata in Pennsylvania . . . 224 

55. Section showing Undulations in Oil-bearing Strata of Penn- 

sylvania * * ' .' . . . ., ;" . . . . 225 

56. Section of the Sulphurous Strata, near Caltanissetta, Sicily . 235 

57. Section of the Sulphurous Strata, near Sommatino, Sicily . . 236 

58. Section of Cupreous Pyrites in Ranenfjord, Norway . . 247 

59. Section of Pyrites Deposit, Huelva, Spain 247 

60. General View of the Rio Tinto Pyrites Mines, Spain. . . 249 

61. Section of Cavity in Limestone, Flintshire, containing Cobalti- 

ferous Iron Ore . v 262 

62. Sketch Section of Nant Uchaf Manganese Mine, near Abergele 289 

63. Section of a Manganese Mine at Pant, near Oswestry . . 291 

64. | Plan and Section of a Manganese Mine near Elbingerode, Hartz, 

65. / Germany 293 



xvi LIST OF ILLUSTRATIONS. 



66. Plan of Haematite Deposit with Manganese, at Steeterwasen, 

Nassau 295 

67. Cross Section of the same 295 

68. Longitudinal Section of the same 295 

69. Sketch of the Rubin Mine, near Niedertiefenbach . . . 297 

70. Section of the Fahrweg Mine, near Niedertiefenbach . . 297 

71. Section of the Hochst Mine, near Niedertiefenbach . . . 297 

72. Map of the Huelva Manganese and Pyrites Mining District, 

Spain 300 

73. Section of the Manganese Deposits at Romaneche Mine, France 302 

74. Longitudinal Section of Workings on the same . ... 303 

75. Manganese Deposit of Cuthbertson Hill, Missouri . . . 306 

76. Section of Manganese Deposit on Burford Mountain, Missouri 306 



PART I. 
EARTHY MINERALS. 

SILICA, ALUMINA, LIME, MAGNESIA, GLUCINA, 

ZIRCONIA, THORIA, WITH SOME OF 

THEIR COMBINATIONS. 




A TREATISE ON 

EARTHY AND OTHER MINERALS 
AND MINING. 

CHAPTER I. 

SILICA AND SOME OF ITS COMBINATIONS. 

Silicon Oxygen Silica Description Proportions in Roek Masses 
Redeposited Silica in Cavities, Cracks, and Beds Daubree's Experi- 
ments on the Decomposition and Crystallisation of Varieties of Quartz, 
Vitreous, Chalcedonic, Jaspery Rock Crystal and its Varieties Chalce- 
dony Agates Flint Chert Jasper Opal Analyses of Rocks 
containing much Silica and Alumina. 

SILICA. 

OF the sixty-four simple elements of which, as far as we know, 
the earth is composed, the most abundant are silicon and 
oxygen. These two, combined in the proportion 51*96 of 
silicon with 48-04 of oxygen, form silica, of which mineral it is 
estimated that two-thirds of the earth's crust is formed. 

The true nature of silica began to be investigated in the 
year 1807 j but it was not understood until a few years afterwards, 
when Berzelius extracted from it the simple .element silicon, 
which, on combining with oxygen in the proportion just given, 
forms the white powder known as silicic acid or silica. 

The simple element silicon has been obtained, by Wohler 
and Deville, in transparent crystals as hard as the diamond, to 
which they bear a certain exterior resemblance ; also in metallic 
crystals imitating graphite, and also in a black non-crystalline 
powder. 



EARTHY AND OTHER MINERALS. 



The colour of pure silica, as seen in crystallised quartz, is 
white ; but along with the combination of silicon and oxygen 
in its composition there is usually a small admixture of other 
substances, chiefly metallic oxides, iron, manganese, &c., as 
hereafter described, and these give to it various other colours, 
including those which make some of its varieties valuable as 
precious stones. 

In hardness, silica ranks as y, 1 and it may be easily dis- 
tinguished in this respect from the fact that it cannot be 
scratched by an ordinary penknife. In a massive form it 
ranges from opaque to translucent, but in separate crystals it is 
transparent. It crystallises into several shapes, the common 

form being a six-sided 
column, capped by a pyra- 
mid of an equal number of 
sides, as shown in fig. i. 

Of itself it is infusible, 
but with soda it melts and 
forms glass. Under certain 
conditions, as will be seen, 
it is soluble. It forms the 






FIG. i. COMMON CRYSTALS OF QUARTZ. 



chief constituent of the 
rock masses of the globe, 
especially among the older rocks. In granitic and gneissic 
rocks it is present to the extent of 66 to 75 per cent. The 
imperfectly cleaved slaty rocks of the Cambrian and Silurian 
strata contain from 60 to 70 per cent. In the greenstone and 
syenitic rocks of the same formations it forms from 45 to 55 
per cent, of the mass, and in the porphyritic rocks of the same 
groups it ranges from 59 to 75 per cent. In the sandstones of 
the millstone grit, the Coal-measures and of the New Red 
Sandstone group of rocks, it is present up to 92 per cent., the 
cementing matter consisting of small portions of lime, alumina, 
and magnesia. Full analyses of several of these rocks are 
given at the close of this chapter. 

In these rock masses, besides alumina, which is in them the 

1 See Table on 'Haidness of Minerals,' in the concluding chapter of 
the book. 



REDEPOSITED AND CRYSTALLISED SILICA. 5 

chief associate of silica, there are proportions of soda and 
potash up to 14 per cent., with small quantities of lime, mag- 
nesia, and the oxides of various metals. . As we shall see in 
treating of clays, it is the presence of soda and potash which 
has, during vast periods of time, facilitated the dissolving of 
the silica out of the mass preliminary to its being redeposited 
with a portion of alumina as clays. 

Besides this great redeposition of the silicious and alu- 
minous portions of the older rocks in beds of clay, another of 
a finer and more delicate kind has also been going on, in 
which silica, variously coloured and combined, has been de- 
posited in veins, cracks, and cavities of those rocks themselves, 
where, according to the age or other conditions of the rock, it 
forms, as quartz, the matrix of gold, copper, lead, zinc, or other 
metallic minerals ; where, in other cracks, the silica has been 
closely packed, the result is an opaque quartz without much 
sign of crystallisation. Where, on the other hand, there has 
been space for the process, it has become crystallised into the 
beautiful transparent forms in which it is found. 

Portions both of the massive quartz, and also of the crystals, 
are beautifully and variously coloured by the presence in 
different proportions of iron, copper, manganese, titanium, and 
other minerals, and these form the source of many of our pre- 
cious stones, which, broken off their parent rock, have been 
rolled and polished as pebbles in the sea, or have been de- 
posited with less friction, and hence are found in a more perfect 
state in conglomerates and breccias near the sources whence 
they were derived. 

Much light was thrown upon the way in which crystals of 
silica and alumina are formed naturally by a series of inte- 
resting experiments made by M. Daubree, in the year 1857, 
resulting in the artificial formation of crystals of these minerals. 

M. Daubree had observed in the mineral springs of Plom- 
bieres, the waters of which contain silicate of potash and soda, 
and have a temperature of 70 Centigrade, the formation of 
certain well-known silicates and other minerals usually found in 
the veins of older rocks. The masonry near the springs was often 
seen to be impregnated with hyalite (a sort of transparent silica 



6 EARTHY AND OTHER MINERALS. 

identical with that found in basaltic rocks), and sometimes 
apophylite (silicate of potash and lime) appeared in nice 
crystals. 

The question then arose with M. Daubree, If hydrated 
silicates form slowly in mineral springs at a not very high 
temperature, may not anhydrous silicates be more quickly pro- 
duced by the action of water at a high temperature ? 

To answer this question he began a series of experiments 
which answered it in the affirmative. The experiments con- 
sisted chiefly in submitting the different substances in the 
presence of water to a heat of 400 Centigrade for a month to- 
gether, in a closed glass tube, protected by an iron case. 

As glass formed part of the apparatus, it naturally occurred 
to him to determine first of all what result this treatment would 
have on glass itself. He found that at the above temperature, 
by the simple action of water, glass undergoes a complete 
decomposition. 

It first becomes opaque, earthy, and fragile, resembling 
kaolin, then gradually and regularly swells and transforms itself 
into a host of minute crystals, which were found on examination 
to be wollastonite (silica 52, lime 48), and at the same time the 
alkalies of the glass were dissolved. Soon the silica was de- 
posited in the form of crystallised quartz. When alumina was 
present, the phenomena were modified. When obsidian was 
acted upon in like manner, minute crystals of felspar were 
formed, resembling in the mass granular trachyte. Clay and 
kaolin, which had been previously purified by washing, on being 
submitted to similar treatment, resulted in felspar mixed with 
crystals of quartz. The presence of oxide of iron in the de- 
composition of the glass gave pyroxene instead of wollastonite. 
This resembled the natural crystals found in the Tyrol and 
Piedmont. The crystals were beautifully crystallised, and 
possessed both their green colour and transparency. 

As the result of these experiments, M. Daubree naturally 
concluded that most, if not all, the silicates found in the early 
crystalline rocks were formed by the influence of water at a 
high temperature, this temperature being, of course, much 
lower than that of the point of fusion of such silicates. 



VARIETIES OF QUARTZ. ROCK CRYSTAL. 7 

Let us now notice those varieties and combinations of silica 
which from their shape, colour, lustre, and transparency have 
been valued as precious stones. 

Quartz. I have already described the way in which this 
variety of silica occurs in veins, lodes, and reefs in the older 
rocks massive, partly in a crystalline form, and crystallised 
usually in six-sided prisms, capped by a pyramid as shown in 
fig. i. It also occurs in radiated and in granular forms. The 
clear white varieties are pure silica, but it is tinged yellow, 
rose, or of a smoky colour, and is, indeed, of all shades of 
colour through the presence of metallic oxides. It has been 
divided into the following three varieties, in which are included 
the precious stones to be described : 

I. VITREOUS VARIETIES. 
II. CHALCEDONIC VARIETIES. 
III. JASPERY VARIETIES. 

I. In the first, or VITREOUS VARIETIES, we have 

i. Rock Crystal. In shape and colour as described above. 
The crystals are usually rooted in a mass of quartz. It is pro- 
bably the mineral described by the ancients as Krustallos, ice, 
whence the word 'crystal.' The crystals are found of small size 
among the mountains of Wales and Scotland, and, indeed, 
wherever the older granitic, slaty, or felspathic rocks are 
found. 

The clearest and finest specimens are brought from the 
island of Madagascar, where they are frequently found in 
blocks ranging from 50 to 100 Ibs. in weight. Fine specimens 
also come from Switzerland, and from Auvergne, in France. 
The rock crystals of this country were formerly known as 
British or Cornish diamonds. It was formerly sold at from 5^. 
to 2os. per Ib. for the purpose of splitting and grinding into 
spectacle glasses, and it was also used for stones for lockets, 
seals, and rings. In the middle of the last century it was 
largely used for buckles and buttons, and many persons were 
employed in cutting and manufacturing it. 

In describing the apatite deposits of Norway, Chapter VII., 
I notice how closely quartz and titanium are associated and 



EARTHY AND OTHER MINERALS. 



interlaced with each other and with apatite, and some speci- 
mens of crystallised quartz are found enclosing slender needles 
and grains of titanium. These examples are known in France 
a&fleches cTamour (love's arrows), as well as crystals of chlorite. 
These specimens are much valued, and are worked up into 
many ornamental articles. 

2. Amethyst is quartz coloured violet and purplish blue, of 
different degrees of intensity, from the presence of the oxides of 
iron or manganese. It passes often in the same specimen 
through rose-coloured to pale red, and even colourless. It 
derives its name from a supposition that it possessed a charm 
against drunkenness. The amethyst occurs in veins in the 
older rocks, and it often forms the inner part of agates derived 
from the same sources. The most valuable are the amethysts 
which come from Ceylon and India ; then those which are 
found in Brazil. Inferior kinds tome from Germany, Spain, 
and Siberia. 

3. Rose quartz, pink, red, and inclining to violet blue in 
colour. Occurs in fractured masses, and is imperfectly trans- 
parent. The colour is most permanent in moisture. Occurs 
at Ben and Rabenstein, in Bavaria. 

4. Smoky quartz. Quartz crystals tinted with a smoky 
colour, becoming sometimes black and opaque. The Cairn- 
gorm stone from the mountains of Aberdeenshire seems to be 
related to the two last varieties and the next to be described. 

5. Yellow or Citron quartz or False Topaz, which is often set 
and sold for topaz, but from which it may be distinguished by 
the absence of cleavage in it. Occurs in light yellow translucent 
crystals. 

There are, besides these, other varieties, as Milky quartz, 
Aventurine quartz, in which the crystals or mass contain 
numerous spangles of golden-yellow mica. The name is said 
to have arisen from the incident of a French experimenter 
dropping at a venture some copper in molten glass, which pro- 
duced a similar appearance. Also Ferruginous quartz, in 
which, from oxide of iron, the crystals are yellow, brownish 
yellow, and red crystals. 



CHALCEDONY. AGATES. 9 

II. In the CHALCEDONIC VARIETIES we have 

1. Chalcedony. Ranges in colour from white through grey, 
green, and yellow, to brown. The bluish varieties are some- 
times called sapphire. It is translucent or semi-transparent. 
It occurs in stalactite, reniform, orbotryoidal masses which have 
been formed in cavities in greenstones and others of the older 
rocks. Into these cavities, as into miniature caverns, water 
holding silicious matter has penetrated and deposited its solid 
contents, consisting almost exclusively of silica tinged by the 
presence of other minerals. Some of these cavities are several 
feet in diameter, and besides the colouring of the encircling 
mass there is often, in the interior of the concretions in them, 
cavities or central nuclea which contain sometimes as many as 
twenty-four different substances, as silver, iron pyrites, rutile, 
magnetite, tremolite, mica, tourmaline, topaz, with water, 
naphtha, and atmospheric air. The mineral occurs in some of 
the mines of Cornwall, in Scotland, Tyrol, Bohemia, and 
Hungary. Some of the crystals are of large size, one in a 
museum in Paris measuring 3 ft. diameter and weighs 8 cwt. 
Chalcedony was obtained in ancient times from the vicinity of 
Chalcedon, in Asia Minor, whence its name. It is now also 
obtained from Scotland, the Faroe Islands, Iceland, India, and 
Arabia. 

2. Agates. In this variety the colours are arranged in con- 
centric undulatory and zigzag lines; in the latter case the 
specimens are known as mural or fortification agates ; also in 
wavy bands as folds of drapery, and in moss-like representa- 
tions, as in the mocha stone, from the presence of manganese. 
All these forms are sometimes seen in the same example if it is 
large enough, together with small kidney and pea shaped con- 
cretions, from the presence of oxide of iron. There is frequently 
also a commingling of the fine cloud-like masses of chalcedony 
with the forms of amethyst, jasper, and agate in the same 
specimens. Figs. 2 and 3 will give an idea of the great variety 
of ways in which these forms of quartz arrange themselves. 

3. Flint consists of silica, which in a very fine condition 
has been .separated from the surrounding rock, and which, 



10 



EARTHY AND OTHER MINERALS. 



attracted to some organic or inorganic nucleus, and sometimes 
only to itself, has grown in successive layers or bands, often of 




FIG. 2. SECTION OF FOLDED AGATE. 

different colours. An illustration of the way in which fine 
silicious particles become separated from the surrounding paste 
or mass is seen in the manufacture of pottery. When the 




FIG. 3. PERSPECTIVE VIEW OF FOLDED AGATE. 

pounded or ground calcined flints are mixed with fine pipe- 
clay, and the mass is allowed to stand for a few days, the silica 



FLINT. CHERT. ONYX. II 

separates itself from the mass, and becomes aggregated into 
small nodules. In like manner have the layers of flints which 
occur so extensively in the chalk formation been separated 
from the limestone paste, and taken their present form. The 
occurrence of layers of flints at certain horizons of the chalk 
seems to indicate that silica was present in greater abundance 
during certain periods of the growth of the chalk beds than 
it was during others. Possibly also temperature and pressure 
may have had something to do with the matter. It has been 
seen that at a pressure of 60 Ibs. in an alkaline solution and 
a high temperature, flint became perfectly soluble. 

Very fine examples of layers of flints in the chalk beds may 
be seen in the range of chalk quarries extending at intervals 
from the city of Norwich to a point beyond the village of 
Thorpe. In some of these quarries I have seen the ancient 
trade of gun-flint manufacture carried on by men who looked 
as if they were survivors of the stone age themselves. Beau- 
tiful examples also of churches and houses built of these flints 
are to be seen in the city of Norwich, and indeed throughout 
the county of Norfolk generally. 

4. Hornstone, or Chert, is allied to flint, but it is more brittle, 
and it takes its colour dirty-grey, red, and reddish yellow, 
green, or brown from the rocks in which it is found. It 
occurs in portions of sandstone rocks usually containing a little 
lime, the fine silica being seemingly collected into one spot. 
Calcareous portions of the beds of the millstone grit, with por- 
tions of rocks of similar composition in the oolite and green- 
sand formations, show this structure. 

Other chalcedonic varieties are Onyx, which consists of alter- 
nate horizontal layers, white, brown, or black in colour. Sard 
from the shores of the Red Sea, of a deep brown or blood red 
colour. Sard and white chalcedony combined form Sardonyx, 
a stone that was much used in ancient time for cameos, of 
which some beautiful specimens remain. Chrysoprase, apple- 
green in colour, from the presence of nickel. Cornelian, a 
clear, rich-tinted, bright red chalcedony, and Cafs-eye, composed 
of 95 per cent, of silica with minute proportions of alumina, 
lime, and oxide of iron, greenish grey, translucent, with a 



12 EARTHY AND OTHER MINERALS. 

shining, vitreous, or resinous lustre, and when cut spherically 
giving the glaring internal reflections like the eye of a cat, 
which come from the presence of asbestos. It is obtained 
from Ceylon and the coast of Malabar. 

It would be an interesting study to inquire into the nature 
of the operations which have resulted in the varied combina- 
tions and arrangements of colour and shape presented in the 
chalcedonic and jaspery variety of quartz, but it is beyond the 
scope of this work. I would refer the readers who feel an 
interest on the subject to a series of clear and beautiful papers, 
with no less beautiful illustrations, by John Ruskin, Esq., F.G.S., 
on brecciated and banded structures, which are contained in 
the fourth and fifth volumes of the Geological Magazine. 

I may, however, say that from the foregoing and other 
considerations, the colours and the grouping of them, and the 
materials, whether partaking more of the nature of simple 
transparent quartz or fine cloudy chalcedony, with the shapes 
and positions occupied by each, would be affected by a number 
of circumstances, as the presence and proportion of metallic 
oxides, and the variations in this proportion at different periods 
during the long growth of the accretions in the mass, or the 
secretions in the cavity or fissure, by temperature, now right 
for the formation of crystals; and then, as in M. Daubree's 
experiments, partially dissolving and rounding them, like the 
rounded apatite, pyroxene and other crystals in the Laurentian 
rocks, then surrounding the perfect or partially dissolved 
crystals with gelatinous matter. Then each mineral present 
would have its natural tendency to crystallise in its own way 
oxide of iron in reniform shape, manganese in dendritic or 
moss-like forms, titanium in long thin prisms, quartz and alumina 
in their prevalent forms, and all these perhaps pressing upon 
and modifying each other. Then there would be times of 
drying and shrinkage, followed by an inflow or addition of pasty 
matter. While, during the partial dissolution of the crystals, 
the matter, becoming soft, would settle down in horizontal or 
other layers according to the foundation on which they rested 
or the nature of the force by which they were pressed. 



JASPER. OPAL, 13 

III. JASPERY VARIETIES. 

1. Jasper, a silicious rock of a hardened clayey nature, of a 
dull red or yellow colour. It has indeed been described as 
ferruginous clay. From the above colours it ranges through a 
great diversity, and often two or more colours are combined in 
the same specimen in bands, dots, stripes, and flames. Like 
chalcedony it occurs in nests, cavities, and concentric nodules. 
Striped green and brown jaspers from Siberia are much used, 
but the most valuable is the Egyptian jasper, in which the 
bands or ribbons occur in excentric zones, which are usually 
cut across to be polished. Ruin jasper presents the appear- 
ance of a group of ruins. Porcelain jasper resembles baked 
clay ; it differs from ordinary jasper in that it is fusible before 
the blow-pipe. Red porphyry is like jasper in some respects, 
but differs from that variety in that it is fusible before the blow- 
pipe. Other varieties are Bloodstone or Heliotrope, Lydian stone, 
Touchstone, and Basanite. 

2. Opal is a hardened paste or gelatine consisting of from 
87 to 95 per cent, of soluble silica with from 5 to 13 per cent, 
of water. Its hardness is less than quartz. 5*5 to 6*5, and its 
specific gravity lighter, 2*21. Its usual colour is milk-white or 
pearl grey, and when looked through towards the light it 
presents with a milky transparence rose red and yellowish 
white, with a rich variation of colours as its position is changed 
emerald and other shades of green, fire red, bright blue, violet, 
purple, and pearl grey. Sometimes the colours are arranged 
in small spangles ; it is then called Harlequin opal; and when in 
broad plates or in wavy or flame-like delineations, the two 
favourite colours being rich orange yellow, when it is known 
as golden opal, and vivid emerald green. The colours are the 
more valued because they are produced by the remarkable 
power the mineral possesses of refracting the sun's rays. Opal 
occurs in veins in porphyritic rocks and in rolled fragments in 
drifted matter. The largest example known is in the imperial 
cabinet at Vienna ; this weighs 1 7 ounces, and belongs to the 
variety known as Precious or Noble opal. Other varieties of 
opal are Fire opal, Girasol, Common opal, Hydrophane, Hyalite, 



14 EARTHY AND OTHER MINERALS. 

occurring in small glassy concretions. Opal is found in the Faroe 
Islands, near Freyburg, Saxony, Kaschan, Hungary, and in 
Honduras. The mineral was much valued by the ancients, 
who called it the " beautiful child of love." And the story is 
told of a Roman senator who gave up his life rather than 
resign an opal ring of great beauty to the Emperor Nero. 

On the next page I give a table of analyses of various rocks 
into the composition of which silica and alumina largely enter, 
but chiefly the former. The higher the percentage of silica, 
the greater, it has been proved, is the power of the stone to 
resist the action of the weather. Since the table has been in 
type I have been favoured with the following analysis of the 
New Red Sandstone worked in the extensive quarries at Grins- 
hill, near Shrewsbury : 

Silica . . - . . . . 95*46 
Alumina . . . . . 1-17 

Iron peroxide . . . . . 0-87 
Lime, carbonate . . .0-61 
Magnesia, carbonate .... -69 

Water, combined . . . . -91 

Water at 212 F. -77 

100-48 

The mean crushing strain of this stone is 5,165 Ibs. to the 
square inch. The amount of silica contained in several other 
sandstones used in building is as follows : 



Craiglieth. . . .93*3 
Barley Dale . . . 96-40 
Corsehill . . . .95-24 



Plean . . . .95-64 
Rawdon Hill . . 92-825 
Spinkwell and Clifford . 88-5 



Before noticing the rock masses of which silica forms the 
chief constituent, let us describe in the next chapter the mineral, 
alumina, with which it is so generally associated, especially in 
the older rocks of the earth's crust, and then, after referring to 
the metallic base, aluminium, and some of the forms in which 
combinations of alumina appear as precious stones, I will pro- 
ceed to notice some of the features and characteristics of the 
rock masses composed chiefly of the two minerals, and record 
some particulars relative to the quarrying of the same. 



ANALYSES OF ROCKS. 



New Red Sandstoae, 
Liverpool. 


O O 00 OO CO 10 O 
10 1-^ OO v> HH t-i ON 
u-> VO iO \O i i -> O\ i 10 
io r- b N 1 1 H o 1 i* 

OO 


100-000 


Calcareous Red Sand- 
stone, Mansfield, 
(Permian). 


^ 1 - - 4 1 r 1 1 1 ^ 

0; | vo co | \o I 1 I <* 


o 

8 


Coal - measure Sand- 
stone, Heddon, near 
Newcastle-on-Tyne. 


% 1 * " I ! 1 1 I " 


o 

8 


Garth Trevor Stone, 
North Wales Mill- 
stone Grit. 


oooo 5^> 

r r 1 ? 9 i i i i \ 9 

>o ^- oo ' ' ' ' ' O 

OO 


1 


Bluish Grey Building 
Stone, from the base of 
the Bala or Caradoc 
beds, Montgomery- 
shire. 


*o o *-o o ^^ *-^ 
O ^J" ^O CO 1 C^ HH 1 W 

VO fO ** 


100-00 


Roofing Slate, Car- 


ooSco oooo o 


g> 


narvonshire, Wales 
(Cambrian Group). 


& 2" "" *^ M M CO 


8 


Light Green Serpen- 
tine, from Galway. 


M O t^ ^ O 

r P 1 ? 1 9 1 1 IP 

O N 1 co ' O i co 


$ 


Basalt from Fingal's 
Cave, Staffa. 


OOOOO^O vO O 
CXJrl-MCOOOiO t-t |O 


<? 

8 


Syenitic Greenstone 


ONOi-'CO (U ' ; *- N "-" 


8 


Portmadoc, North 
Wales. 


OOOlO<q-gN 10 |W 

vo w i! 


8 


Rose - coloured Por- 
phyry from Green- 
ville, Canada. 


OOOO O oo O 
w 10 O\ I~>. i 1 co OO 1 vO 

N M O fO 1 1 io CO 1 b 


! 


Granite from Fox 


8^-J. ^- ^f- HH CO >-< O 
v> OO ^ | CH 10 N I M 


o; 


Rock, near Dublin. 


CO fO HH N ro rj- 


& 










: : : 1 1 : : : 1 1 

g o ? -i .a 

1 1 ill Illll 





16 



CHAPTER II. 

ALUMINA, MAGNESIA, LIME, WITH SOME OF THEIR 
CO MB IN A TIONS. 

Aluminium Alumina Bauxite Valued Forms of Alumina Corundum 
Sapphire Ruby Topaz Brazilian Deposits of Emerald Analyses 
of Beryl Emerald Mines of Grenada Tourmaline The Precious 
Stones Deposits of Ceylon More Massive Forms of Silica and Alumina 
Orthoclase Adularia Felspar Mica Magnesia Magnesium 
Talc Steatite Chlorite Serpentine Pyroxene Asbestos Rock 
Masses Granites and Gneiss^Rocks Syenitic and Dioritic Greenstones 
Slaty Building Stones Liverpool Corporation Quarry, Llanwddyn 
Felspathic Rocks of North Wales Lime and Limestones Varieties 
of Costs of working Glucina, Zerconia, Thoria Chemical Composition 
of various Limestones. 

ALUMINA. 

ALUMINA consists of aluminium and oxygen in the propor- 
tion of two parts of the former to three of the latter. In 
ordinary use alumina is a white powder, shapeless, infusible, 
and scarcely soluble. In a crystalline form it is found in the 
most perfect state as corundum. In an impurer state and 
mixed with other substances it becomes opaque, as in the case 
of emery, a common form. It is a mineral very abundant in 
nature, forming, as will be seen in the following analysis, from 
one-fourth to one-third of the substance of many of the older 
rocks of the earth's crust. Its specific gravity is 3-9. It is 
largely used in the processes of dyeing and calico-printing. 
Aluminium, the metallic base of alumina, is a light, whitish- 
coloured metal of bright lustre, which, as far as it has been 
worked, has been found very useful in the manufacture of 
optical and mathematical instruments, and for the lighter kinds 






ALUMINIUM. BAUXITE. 1 7 

of ornamental work. Its specific gravity is only 2 '6. The 
extraction of the metal from its earthy surroundings has been 
carried on during the greater part of the last twenty years at 
Newcastle-upon-Tyne, with but indifferent success, the process 
being costly and intricate. Recently, a Birmingham manufac- 
turer claims to have discovered a more simple and much 
cheaper process. Four parts of aluminium mixed with ninety 
parts of copper affords an alloy possessed of the greatest 
strength combined with malleability and ductility, and other 
alloys are being constantly adopted. 

The material chiefly used for its production hitherto has 
been bauxite, a ferruginous clay obtained from Baux, near 
Aries, in the south of France. Its general composition is as 
follows : 

Alumina 57-4 

Silica 2-8 

Sesquioxide of iron .... 25*5 
Oxide of titanium . . . . 3-1 
Carbonate of lime . . . 0-4 

Water . 10-8 



100-0 



A similar material, containing from 44 to 54 of alumina and 
from i to 15 per cent, of iron, has also been used at New- 
castle from the mines of the Irish Hill Company, Ireland. 

It will be readily inferred that aluminium is one of the most 
abundant metallic minerals in nature. 

To simplify its extraction from the clays and rocks in which 
it is contained is one of the greatest metallurgical problems of 
the present time. As this is solved many of the clays de- 
scribed in another chapter will become more valuable, and the 
metal more largely used. 

Let us now notice some of the forms and combinations of alu- 
mina which on account of their beauty have been greatly valued. 

Corundum is, as already observed, pure alumina in a crystal- 
line condition. The forms are somewhat varied, but it occurs 
chiefly in six-sided prisms, as shown in fig. 4. It also occurs 
in a granular form. Its usual colours are blue and greyish blue, 

c 



1 8 EARTHY AND OTHER MINERALS. 

but it is also found red, yellow, and brown of various shades. 
Translucent to transparent. The specific gravity is from 3-9 to 
4* 1 6, and in hardness it ranks next to the diamond, 
scratching quartz easily. Except with borax it is 
infusible before the blow-pipe. Comminuted 
corundum occurs abundantly near Canton, and is 
much used in that city in the polishing of precious 
FIG. 4. COM- stones. Among the varieties of corundum are 
' Sa PP hire - The general composition of 
which is alumina 92, silica 5*25, oxide of iron ro. 
The colour most valued is a highly transparent bright Prussian 
blue. More frequently the colour is a pale blue, passing by paler 
shades into perfectly colourless varieties. The paler varieties 
are frequently marked by dark blue spots and streaks, which 
detract from their value. But these paler varieties lose their 
colour when subjected to great heat, a fact that has sometimes 
been taken advantage of by unscrupulous dealers to pass them 
off as diamonds. 

The principal form of the sapphire is an acute rhomboid, 
but it has many modifications and varieties. On being broken 
it shows a conchoidal fracture, seldom a lamellar appearance. 
The best sapphires were formerly found chiefly in Ava and 
Pegu ; the paler varieties in the sands of rivers in Ceylon, 
inferior kinds being obtained from near Forez, in France. 
More recently the sapphire has been found in many localities in 
the United States of America. It belongs to the older gneissic 
and talcose rocks and granular limestones, and with fragments 
of these it is found in driftal deposits. 

The sapphire is a gem prized next to the diamond. The 
largest known weighs about two ounces. There was also a fine 
rhomboidal crystal among the crown jewels of France, which 
weighed over an ounce. 

2. Ruby. The ruby is subdivided into several varieties 
according to colour, which in its turn is affected by mineral 
composition, spinel ruby occurring in bright red or scarlet 
crystals, rubicelle of an orange red colour, balas ruby rose 
red, adamandine ruby violet, chlorospinel green, and pkonaste is 



RUBY. TOPAZ. 

the name given to dark varieties. The three 

the difference in the composition of three spinel rubies. 




I. 
Alumina . . 
Silica . . . 
Oxide of Iron 


. 90 

7 

1-2 


2. 

Alumina . . 
Magnesia . . 
Chromic acid 


82-47 
8-78 
6-18 


3- 
Alumina . . 
Magnesia. . 
Silica . . . 


. 69-0 

. 26-2 

2 


Goss . . . 


. 1-8 






Oxide of iron 


'7 




100- 




97'43 


Chromic acid 


T-I 


99'0 



The first of these is most nearly allied to corundum. Its 
hardness is slightly less than that of the sapphire, and it is 
infusible before the blow-pipe, except with borax, and then it is 
fused with difficulty. Its specific gravity is about 3*9. 

The crystals are usually small, and when not defaced by 
friction they have a brilliant lustre, as has also the lamellar 
structure, with natural joints, which it shows on being broken. 
It exhibits various degrees of transparency. The colour most 
valued is the intense blood red or carmine colour of the spinel 
ruby. When the colour is a lilac blue, the specimen was 
formerly known as the Oriental amethyst, and was regarded 
as a connecting link between the ruby and the sapphire. 
Rubies are found in Pegu, in the sand of rivers near the town 
of Siriam. It is also found with the sapphire in the river 
deposits of Ceylon, and in various localities in the United 
States of America, in some of which the crystals have partly 
decomposed, and show a soft structure resembling steatite. 
In America it occurs in gneissic and metamorphic rocks, and 
in granular limestones. 

3. Topaz derives its name from topazo, to seek, the mineral 
first known by this name being obtained from an island in the 
Red Sea which was usually surrounded by fog. 

Two examples of the mineral now known by this name, 
gave on analysis the following results : 






Alumina . 
Silica 
Fluoric acid 



50-0 
29-0 
19-0 

98-0 



Alumina 

Silica 

Fluorine 



57'5 

34*2 

I5Q 

1067 



20 EARTHY AND OTHER MINERALS. 

It varies in size from two carats to three or four ounces. 
The specific gravity is 3*53. 

By itself it is infusible before the blow-pipe. It possesses 
a brilliant transverse cleavage. It has a lustre greater than 
that of rock crystal. Fine topazes of a greenish yellow colour 
to perfectly white come from Siberia, Kamtchatka, and Australia. 
Pale greenish ones are found in the Highlands of Scotland, 
and small colourless examples come from St. Michael's Mount, 
Cornwall. 

Topazes are found in large numbers in the neighbourhood 
of Villa Rica, in Brazil. They occur in small veins partially 
filled with talcose matter, and associated with quartz and 
specular iron ore. They are also found by thousands in the 
debris derived from the wearing down of granitic and gneissic 
rocks, perfect specimens being, however, rare. The searching 
for them and the preparation of them for sale is a consider- 
able industry, and gives employment to a large number of 
persons. 

The Brazilian topazes are of three kinds : blue, also called 
Brazilian sapphire ; the yellow, of various shades of yellow ; 
the deeper the colour, so that the stone retains its transparency, 
the more valuable it is. This on exposure becomes pink and 
red in colour, when it is known as the Brazilian ruby. These, 
with the white topaz, are found in a rolled, and more rarely a 
crystallised form, in the conglomerate described in the chapter 
on the diamond. 

The topaz has sometimes been mistaken for the diamond. 
Apart from the suspicion that some supposed diamonds in 
royal collections are topazes, a notable instance of a mistake 
of this kind occurred in the year 1856. A topaz supposed to 
be a diamond was brought from Brazil, weighing about 189 
carats, or about twenty-five ozs., and caused great excitement 
in Europe. It was estimated to be worth several million francs. 
At last a consultation of authorities was held in Vienna, the 
result of which was the statement ' The pretended diamond 
turns out to be a topaz, having the specific gravity and the 
hardness of an ordinary topaz, and is worth as a curiosity about 



COMPOSITION OF EMERALDS. 



21 



250 francs.' Common topaz is found abundantly in the vicinity 
of Falun, Sweden. 

4. Emerald. Beryl. The emerald is of a beautiful rich 
green colour, passing also into blue and yellow. It crystallises 
in six-sided prisms. It has a vitreous or resinous lustre, and 
varies from translucent to transparent. The following are the 
result of some analyses of the emerald and its varieties. 

Emerald from Mexico. 
Silica . 
Alumina 
Glucina 
Magnesia 
Oxide of iron 
Soda . 
Titanic acid 

Oxide of chrome . 
Lime . 



CO. 

67-9 


-c/meram irom imana. 


-C-meram iro 


17-9 


16-465 


16-6 


12-4 


12-747 


13-0 


0-9 











1-490 





07 








trace 


0-280 











i -06 


99-8 


98-341 


99-42 



Beryl, or Aquamarine. 
Silica . 
Alumina 
Glucina 
Oxide of iron 
Lime . . 



68 



i 

2 

100 



Chrysoberyl, or Cymophane. 
18 
71 



The specific gravity is about 27, its hardness greater than 
that of quartz. Before the blow- pipe it is fusible into a grey 
and rather frothy glass. 

The emerald was formerly obtained from Ethiopia, and was 
prized in ancient times. Necklaces of emeralds have been 
found in the ruins of Herculaneum. The chief source during 
the last three hundred years has been Peru, in the vice-royalty 
of Santa Fe ; and in the valley of Tunca, between the 
mountains of New Grenada and Pompaya, they are found in 
veins traversing clay slate, and in cavities in certain granites. 
They are accompanied by quartz, calcareous spar, felspar, mica, 
and pyrites. The largest emeralds known are from Peru. They 
are about six inches long by two inches thick, but the largest 
specimens are seldom the purest. 



22 EARTHY AND OTHER MINERALS. 

A productive emerald mine is, or was, that of Muso, in New 
Grenada, Mexico. The emeralds occur in veins and cavities 
in a black limestone that contains fossil ammonites. The 
limestone also contains within itself minute emeralds, and an 
appreciable quantity of glucina. When first obtained the 
emeralds from this mine are soft and fragile ; the largest and 
finest emeralds could be reduced to powder by squeezing and 
rubbing them with the hand. After exposure to the air for a 
little time they become hard and fit for the jewellers' use. In 
Eeryl, or Aquamarine, the colour is a pale sea-green, passing on 
one side to light sky blue and greenish blue, and on the other 
into greenish yellow. Sometimes the same crystal presents 
two or more colours, and sometimes it is iridescent. 

5. Tourmaline is composed of from 40 to 43 per cent, of 
silica, and about the same quantity of alumina, about 10 per cent, 
of soda, with up to 8 or 9 per cent, of manganese. It crystallises 
in prisms, with three, six, nine, or twelve sides. It is green in 
colour, ranging to blue, red, yellow, and brown. It is harder 
than quartz, and its specific gravity is from 3*0 to 3-3. It fuses 
before the blow-pipe into a spongy greyish white enamel. It 
is found in Siberia, Ava, and Ceylon, also in Brazil, where the 
stone is much worn in rings by the ecclesiastical dignitaries. 

In the foregoing descriptions of precious stones, reference 
has been frequently made to Ceylon as one important source 
whence many of them have been derived. 

The gems occur in an ancient gravel deposit, known as 
Nellan, which is frequently from ten to twenty feet below the 
surface. It consists of fragments and pebbles of granite, gneiss, 
and other of the older rocks imbedded in clay. It is covered 
by a hard crust a few inches in thickness, called Kadua, and 
which in places protects the underlying Nellan from the action 
of the streams. This is overlaid by recent gravel. In the 
Nellan there are large lumps of granite and gneiss in the 
hollows, as well as in pockets in the clay, which are known 
by the natives as elephants' footsteps. In and about these the 
precious stones occur in groups, where they are found by the 
miner. 



GEM DEPOSITS OF CEYLON. 23 

The gem collector digs down to this stratum ; he takes the 
clayey gravel out and places it by the side of his digging until 
he has accumulated three or four cubic yards. He then carries 
it in shallow basin-like baskets from two to three feet in 
diameter to a neighbouring stream, where he washes it until all 
the clay has disappeared, leaving only the sand containing 
gems behind. The gems are then carefully picked out, the 
washer removing with the.palm of his hand one thin layer after 
another until the whole of the sand has been effectually 
searched. 

The industry is not encouraged by the Government ; inas- 
much as it attracts a numerous loose population from agricul- 
tural pursuits and the more steady industries of the country. 
It is after all a poor trade, although now and then a lucky 
find is made. The chief town of the gem district is Ralna- 
poora, where most of the stones are polished. 

The materials of the Nellan or gem drift, seem to have been 
derived from the wearing down of the large grained silicious 
granitic rocks that abound in parts of Ceylon as well as in Pegu, 
and along the coasts of China and Japan northwards. Results 
of this decomposition of these granitic rocks may be seen along 
the coasts of Japan in the loose sand that covers and gradually 
passes into the solid parts of the rock. 

Other varieties of the combinations of silica and alumina 
with other substances as precious stones will be found in the 
concluding chapter, and we may now proceed to notice those 
combinations of the two minerals with others that contribute 
largely to the formation of the rock masses which, valuable in 
themselves as building and other stones, form also the deposi- 
tories of the minerals, metallic and otherwise, described in this 
book and its companion volume. 

Felspar. Orthodase is composed of silica 64-20, alumina 
18*40, and potash 16*95. ^ crystallises in oblique rhombic 
prisms. Its common colours are white, grey, and pale red ; 
but it also passes into greenish and bluish white. It has a 
vitreous and occasionally pearly lustre. Its hardness is 6, and 
it may be scratched with a good penknife. Specific gravity 



24 EARTHY AND OTHER MINERALS. 

2*39 to 2*62. It is not affected by acids, and it fuzes with 
borax into a transparent glass. 

One of the finest varieties of felspar is that known as 
Adularia, from Mount Adula, near the St. Gothard Pass, where 
it is found redeposited from the rock mass in veins and 
cavities. It consists of silica 64, alumina 20, lime 2, and 
potash 14. Moonstone is another variety with bluish white 
spots of a pearly lustre. Sunstoneis another, with a pale yellow 
colour, with minute scales of mica. Aventurine felspar, sprinkled 
with iridescent spots from the presence of minute particles of 
titanium or iron. 

Mica. Chemical composition: silica 46-2, alumina 36-8, 
potash 9*2, peroxide of iron 4*5, fluoric acid 0*7, water 
i '8. In colour ranging from white to green, yellow, brown, 
and black. Pearly lustre, tough and elastic ; occurs in thin 
plates or scales, and sometimes in radiated groups of the same. 
H. 2* to 2*5; gr. 2*8 to 3*. Mica differs from talc in not 
having the greasy feel of the latter, and in its thinner and more 
elastic plates; some of these occur of considerable size. They 
have been used in Siberia for glass ; hence the name Muscovy 
Glass. Plates two or three feet diameter, and quite transparent, 
are found in New Hampshire. 

We must now add to our list another of the earthy minerals, 
which, to a considerable extent, enters into the composition 
of the rock masses of the earth. 

MAGNESIA. 

Magnesia is a compound of magnesium and oxygen, in the 
proportion of 158 parts of the former to 100 parts of the latter. 
It is the only oxide of magnesium. 

Magnesium. This simple element is the metallic base of 
magnesia. It has in the metallic state the colour and lustre of 
silver; it is malleable, and fuses at a red heat, a little above 
which point it burns with great brilliancy, oxidizes, and forms 
magnesia. It also oxidizes on exposure to a moist atmosphere, 
but it is not affected in dry air. 

Magnesia is a soft white powder, which is highly infusible. 



TALC. CHLORITE. SERPENTINE. 25 

It combines with water, but not so readily as lime. The 
artificial preparations of magnesia by precipitation from its 
soluble salts have the silkiness, lustre, and softness which 
are observed in asbestos, soapstone, and other magnesian 
minerals. 

Among the minerals helping to form rock masses into 
which magnesia enters are the following : 

Talc. Composition : silica 62-8, magnesia 32-4, protoxide 
of iron 1*6, alumina ro, water 2*2. In some examples 
the water amounts to 4 per cent. H. = i ; gr. = 25 to 29. 
Occurs usually in foliated masses made up of thin easily sepa- 
rable plates. It also passes into a crystalline, granular, and 
a fine impalpable texture. It has a pearly lustre, and, with 
most other minerals into which magnesia enters, it has an 
unctuous feel; colours silvery white, greenish white, grey, 
green, and olive green. Some forty years ago it was much 
used in the manufacture of lamps and lanterns, more so than 
at the present time. It includes Foliated Talc, Soapstone, or 
Steatite, a massive variety of talc of a grey or greenish colour, 
and internally a crystalline texture ; feels to the touch like soap. 
The composition of steatite is silica 62*2, magnesia 30*5, 
protoxide of iron 2*5. It is flexible, but not elastic like mica. 
Potstone, an impure talc, is another variety. 

Steatite occurs abundantly in America. In small quantities 
it may be found in many rocks. From the facility with which 
it can be cut, drilled, and worked generally, and the polish it 
will take, it has been used for various internal portions of archi- 
tecture. It is also used in the manufacture of porcelain, as a 
lubricant for machinery, and in the final polishing of the harder 
stones. 

Chlorite. Chemical composition : magnesia 34*0, silica 30*4, 
alumina 17, protoxide of iron 4*4, water 12-6. H. = 1-5, 
gr. 2*85. Occurs in masses of a dark olive green colour, and 
crystallises into hexagonal prisms. Occurs in thin plates and 
radiated forms like talc, pearly lustre, opaque to partly trans- 
lucent. It is distinguishable from serpentine by a granular 
texture, and from talc by its yielding water in a glass tube, and 



26 EARTHY AND OTHER MINERALS. 

from green iron earth by its extreme infusibility. Chlorite 
enters largely into the composition of schistose and slaty rocks. 

Serpentine occurs in dark oil or olive green masses, also in 
a fibrous and lamellar form. These consist of thin plates or 
folia of a greenish white to dark green colour. H. 2*25 to 4/0; 
gr. 2*5 to 2 '6. An analysis of a rock variety is given in the 
table, page 15, and the following is the composition of a 
purer variety from Cornwall, known as Precious serpentine : 
magnesia 44*2, silica 42^3, protoxide of iron 0*4, carbonic 
acid 0*9, water 12*4; capable of a high polish, and forms a 
beautiful stone. Becomes brownish red before the blow-pipe 
and gives off water. Another variety, named Marmolite, is 
brittle, but consists in easily separable thin folds. Its com- 
position is : magnesia 41*4, silica 40-1, protoxide of iron 2*7, 
water 15-7. Serpentine of various kinds is worked in Corn- 
wall and in America as ornamental stones, but it does not bear 
exposure to the weather. 

Pyroxene occurs in various shades of green, passing towards 
white on one side, and brown and black on the other, yellow 
excluded. It has a vitreous lustre, inclining to resinous or 
pearly. In the massive varieties there is a coarse granular and 
sometimes fibrous structure, the fibres long and thin ; crystal- 
lises in oblique rhombic prisms. The composition, as to the 
minor constituents, is somewhat varied, but the crystalline 
forms remain unchanged. H. = 5*6 ; brittle; gr. = 3*2, 3*5. 

Pyroxene has been divided into three groups or divisions : 
the white or light coloured, the dark coloured, and the thin 
foliated. 

I. White Augite or Malacolite includes several lesser 
varieties. Its general composition is: silica 55*3, lime 27-0, 
magnesia 17-0, protoxide of iron 2*2, protoxide of man- 
ganese 1-6. 

II. Augite also includes several dark green varieties, in 
which there is a larger proportion of iron and manganese than 
in the first. The composition of one variety is given as 
silica 54*1, lime 23*5, magnesia 11*5, protoxide of iron 10*0, 
protoxide of manganese 0*6. 



HORNBLENDE. ASBESTOS. 27 

III. The third class includes Diallage, Bronzite, and 
Hypersthene, all of which are characterized by being thin 
foliated. The composition of hypersthene is given as : silica 
54*25, lime 1*5, magnesia 14*0, protoxide of iron 24*5, 
protoxide of manganese a trace, alumina 2-25, water 1*0. 

HORNBLENDE. Occurs in oblique rhombic prisms, long 
slender prisms, in columnar forms, and in fibrous masses of 
coarse and fine fibres, silken and like flax. In colour it ranges 
from white through bluish green, greyish green, green, and 
brownish green shades to black ; a vitreous lustre, the faces of 
the plates or cleavage lines inclined from pearly opaque to trans- 
parent. H. = 5 to 6; gr., 2^9 to 3*4. Hornblende is divided 
into first, the light-coloured varieties, and second, into the dark- 
coloured varieties. The former include Actinolite and Asbestos, 
with the sub-varieties belonging to each. These varieties are 
distinguished by not containing much alumina or iron. The 
composition of glassy actinolite is as follows: silica 59*75, 
magnesia 21*1, lime 14*25, protoxide of iron 3*9, protoxide 
of manganese 0*3, hydrofluoric acid 0*8. 

The dark varieties include Hornblende, the composition of 
which is : silica 48*8, magnesia 13*6, lime 10*2, alumina 7*5, 
protoxide of iron 18-75, protoxide of manganese 1-15, hydro- 
fluoric acid and water 0*9. 

Another variety is Pargasite, from Pargas, in Finland. This 
occurs in short thick crystals, and is composed as follows : 
silica 46*3, magnesia 19*0, lime 14*0, protoxide of iron 3*5, 
protoxide of manganese 0*4, hydrofluoric acid and water 2-2. 

Asbestos. Before leaving hornblende it may be well, on 
account of its rising commercial importance, to say a few words 
concerning this mineral. It was known to the ancients, who 
made of it the wicks for the lamps in their temples. These 
wicks served to feed the flame with oil up their fine fibres, but 
remained unconsumed ; hence the name asbestos uncon- 
sumed. The natives of Greenland now use it for the same 
purpose. Because it was easily cleaned the ancients gave it the 
name Amiantus undefiled. It is now woven into cloth for 
packing the joints of steam-engines and machinery. It helps 



28 EARTHY AND OTHER MINERALS. 

to form an excellent non-conducting cover for boilers. It is 
woven into fireproof garments, and for many other purposes. 
It occurs in large masses in felspathic and chloritic rocks. I 
have seen it in a coarse form associated with the greenish 
apatite-bearing rocks of South Norway. It is largely obtained 
at present from Italy for English manufacturers. It occurs in 
various forms in slender flax-like fibres, and with a rich satin 
lustre, in seams in the rocks ; in a hard and compact form of 
yellow and brownish colours, Ligniform Asbestos ; in thin, tough 
sheets, like leather, Mountain Leather, which consists of thin 
beds or layers of matted fibres of asbestos ; and in thicker 
masses of the same, Mountain Cork. 

We may now proceed to notice some of the rock masses 
into the composition of which the minerals already described 
enter, as shown in the analyses given on p. 15. 

Granites. The particular composition of granites is given in 
the table. It is generally described as consisting of quartz, felspar, 
and mica, the first being pure silica, and the other two consti- 
tuted as already described. There are, however, many varia- 
tions, according* as one or other of the minerals predominate, 
or the precise form in which it is present. Thus, felspar may 
be present as orthoclase, oligoclase, or albite, or two of these may 
be present. There may also be two kinds of mica present, and 
occasionally mica is replaced by hornblende. The crystals of 
felspar may be large and distinct, and the rock thus assume a 
porphyritic structure. These variations affect the colour. An 
abundance of flesh or pink-coloured felspar gives a reddish 
tint, like that of the granite of Peterhead. White felspar, or a 
preponderance of quartz, gives, with mica, a grey speckled stone, 
while hornblende imparts a greenish cast. 

When the grains or particles are arranged in layers, the 
stone is called Foliated Granite. When this bedding becomes 
very distinct and the particles are fine, granite becomes gneiss, 
like those of Donegal and Galway, and the masses resting upon 
the older coarser granites of Norway and Sweden. Occasion- 
ally the particles of felspar are arranged in the quartz, or the 
quartz in the felspar, like the letters in Oriental writing, and 
then it is known as Graphic Granite. The names Quartzose 



GRANITE. COST OF QUARRYING. 29 

Granite, Felspathic Granite, and Micaceous Granite are given as 
one or other of the minerals predominate in the composition. 

Granite was long considered to be of igneous origin, but 
the arrangement of the particles in layers, the presence of 
water in the quartz, with other considerations, have tended to 
modify this opinion. It would seem to be a sedimentary rock 
altered, and we may have granite in various stages of its his- 
tory in its original sedimentary form ; when altered by heat ; 
when protruded or injected from altered masses deep down 
in the earth through other rocks; or with the arrangement 
of its particles altered by pressure, similar to that which has 
produced the phenomena of slaty cleavage. 

Generally speaking, granitic and gneissic rocks lie near the 
base, as far as this is known, of the geologic series. We see 
this in the position occupied by these rocks on the western 
coast of Great Britain, from St. David's up to Scotland, 
in the position of similar 'rocks in Ireland, in the position 
of the main bosses of granite in Devon and Cornwall, in the 
arrangement of the rocks all over the peninsula of Norway and 
Sweden, and in the place occupied by them in most of the 
great mountain chains of the world. 

There are exceptions. The granites of the Alps and of the 
eastern Pyrenees are believed to be newer than the chalk. 
May it not be that these more recent granites, like some 
probably in Cornwall, are projected or intrusive granites, 
portions of the old vast underlying expanse of the ancient 
granites thrown up through and over the newer strata ? 

Granitic and gneissic rocks are not usually difficult to work. 
The component parts are hard, but the grain is open, and as a 
rule not more, if so much, is paid for boring or drilling and for 
driving tunnels or sinking shafts in them than is paid for the 
same work in the slaty rocks of Wales. 

In Norway and Sweden the price paid for boring i holes 
is f d. per inch, or gd. per foot. For driving a tunnel 7 ft. by 
6 ft., 7/. icxr. per fathom ; for sinking shaft 12 ft. by 8 ft., gl. to 
i2/. per fathom ; for open cuttings about 12 ft. wide, 25^. per 
cubic fathom. These were all in gneissic rock. The rate of 
wages being lower in these countries than in England, similar 



30 EARTHY AND OTHER MINERALS. 

work would cost more here. Some of the close-grained granites 
in Scotland are difficult to drill, and it is found advisable to bring 
large masses of rock down at once by sinking a shaft or driving 
a tunnel, and putting a large quantity of explosive in them. 

Syenitic and dioritic greenstones, which lie at the base of 
the Arenig or Lower Llandeilo strata, are largely quarried in 
North Wales for paving setts, curbstones, road-metal, and to 
some extent for building stones. Extensive quarries in these 
rocks are worked on Penmaenmawr, and near Portmadoc in 
Carnarvonshire ; while down the north coast of the promon- 
tary of Lleyn, in the same county, rocks more nearly approach- 
ing a syenitic granite are largely quarried for the same purpose. 

The costs of quarrying and forming a ton of paving setts, 
at one of these quarries when in full work, may be taken as 

follows : Per ton 

of Setts. 
s. d. 

Quarrying, including removal of top rock . .26 
Sett making (average price) . . . .90 

Royalty 02 

Powder and fuze 05 

Management in and out of quarry . . .19 

Trammers and labourers 13 

Loading, smiths, and contingencies . . .010 

15 II 

Basalt, consisting of augite, olivine, and felspar, is largely 
quarried for setts and road materials on the Glee Hills, Shrop- 
shire. 

For particulars as to the position, varieties, and costs of 
quarrying the slate rocks of Wales, I will refer the reader to my 
work on that subject. 1 In a very few places portions of 
these are quarried for building stones, the most notable example 
at the present time being the extensive quarry recently opened 
out by myself and son in connection with the works of the Liver- 
pool Corporation Water Supply, near Llanwddyn, Montgomery- 
shire. Here the beds are about three feet thick. The stone is too 

1 Slate and Slate Quarrying, by D. C. Davies, F.G.S. Crosby Lock- 
wood & Co., 7, Stationers' Hall Court, London. Second Edition, 1881. 



LIME AND LIMESTONES. 31 

silicious for the cleavage to be perfect, although the lines are 
seen very distinctly. The rock crystallises in large masses in a 
rhomboidal form, the strike being N.E. to S.W., and the cracks 
or joints of shrinkage running to the east. The stone also cuts 
well along the line of its strike, answering to the pillari or pleri 
of the slate beds. In some of the beds where there is a little 
lime there is a tendency in the large blocks to break in five 
and six-sided columns. It is thus interesting to trace the same 
tendency to crystallise in particular forms, from the tiny crystal 
lining the side of a cavity, to the arrangement of rock masses 
on a large scale. This rock is exceedingly tough and hard, 
and capable of resisting great pressure. The general composi- 
tion of the rock is silica 60, alumina 30, potash, soda, lime, 
andiron io'o. A tunnel for the outlet of the water is now 
being driven through these beds at 8/. $s. yer yard, the length 
being about two miles; the cost of hand-boring is about 10^. 
per foot. Interstratified with these beds, there are all through 
North Wales beds of felspathic rock, very dense and compact. 
The cost of working in these is more than double that of 
ordinary slate rocks. 

Of the same age probably as these felspathic and porphyritic 
bands or beds that over so large an area are interstratified with 
the Lower Silurian of North Wales, are some of the porphyries 
and serpentines of Cornwall, which furnish very beautiful build- 
ing stones for in-door work. 

Higher up in the geological series are the sandstones of the 
Coal-measures and of the New Red Sandstone, composed chiefly 
of silica, and being granular, and when first quarried somewhat 
soft and loose in texture, they are quarried with ease, the 
stones being often got out of the rock with wedges, and after- 
wards reduced to the desired size by the same method. 

LIME AND LIMESTONES. 

Calcium. The metallic base of lime is the simple element 
calcium, which was made out, and its relative position to other 
metals assigned, by Sir Humphrey Davy. The name is derived 
from that given to lime (kalk) in several languages. Limestone 



EARTHY AND OTHER MINERALS. 




FIGS. 5 AND 6. CRYSTALS OF CAR- 
BONATE OF LIME. 



consists of carbonate of lime, allied more or less with silicious' 
aluminous, and other matters. Pure carbonate of lime is seen 
in cracks and cavities in limestone masses, and in many 
stalactites and stalagmites occurring in large caverns in the 
same. It is composed of lime 56*0, and carbonic acid 440, 
the latter being made up of carbon 27*65, and oxygen 72-35. 
It occurs in masses chiefly white and light coloured, but rang- 
ing in some instances to black. It crystallises into various 

forms, of which two examples are 
given in figs. 5 and 6. 

The crystals are of various 

^--T"--^ / / \ \ C l urs 5 white, grey, yellow, and 

|{~l f-L-JL-M re d> according as they contain 

* ' ' ' metallic oxides or other matters. 
H. = s;gr. 2-5 to 2-8. 

Among the varieties of car- 
bonate of lime are the follow- 
ing: 

i. Argentine, containing a 

little silica, with wavy laminse, and of a white shining appear- 
ance. 

2. Calcareous Tufa, a porus or cellular kind, formed in the 
hollows and in the vicinity of limestone strata, from water 
flowing over the latter, and becoming charged with carbonate 
of lime. Rock-milk is the name for it before it becomes 
consolidated. 

3. Chalk, forming large masses of strata, soft, and rather 
earthy. 

4. Iceland Spar, from Iceland, and famed for its double 
refracting property. In transparent crystals. 

5. Stalactite, Stalagmite. Deposits like tufa formed in 
caverns and showing frequently rings or layers coloured by 
other mineral matter. 

There are also the rock masses of limestone, that occur in 
almost every geological formation, from the oldest to the 
youngest. 

Crystalline limestones occur in the Laurentian rocks of 



COST OF LIMESTONE QUARRYING. 33 

Canada, as shewn in fig. 12, Chapter VII., and form the depo- 
sitories of apatite. 

There are the bands of limestone, Llandeilo and Bala, 
which occur in Great Britain, in the Lower or Cambro-Silurian 
strata, and in other counties in strata of similar age. 

In the Upper Silurian there are the Wenlock and Dudley 
limestones, famous for the beautiful forms of sea organisms 
they contain. 

In the Middle Devonian there are limestones which are 
seen in this country, but which are developed to a greater 
extent on both sides of the Rhine, in Germany. 

This brings us up to the great mass of the Carboniferous 
Limestone, so well developed in Great Britain. 

A belt of varying thickness skirts the north side of the 
South Wales coal-field. A similar belt bounds the west side 
of the North Wales coal-field, on the borders of England and 
Wales. This dips under the great red sandstone plain of 
Cheshire, and re-appears in the Derbyshire hills, whence it 
may be followed northwards through the counties of York, 
Durham and Northumberland, forming the great backbone of 
the country, and the depository of lead and zinc ores. Similar 
bands or belts encircle the Scottish coal-fields. 

Fine marble and building stones are obtained from this 
group in Anglesea, while those of Derbyshire, with their 
abundant fossil remains, are well known. The same is true of 
the carboniferous limestone in other countries. 

It is also very extensively quarried for agricultural use, 
being burnt in kilns and spread upon the land, where it helps 
to dissolve other minerals, and enables the plant to assimilate 
them. The light coloured and purer beds are also largely 
quarried for fluxing stone used in the smelting of iron, and 
also in the manufacture of glass. 

The following particulars relative to the quarrying and 
burning of lime may be interesting and useful. They relate 
to the North Wales lime region. 

Price paid to men for getting stone, and loading it in 
waggons, from *]d. to 8tf. per ton, the men finding thc-ir own 

D 



34 EARTHY AND OTHER MINERALS. 

powder, but drills and tools found, sharpened, and repaired by 
the owners. This is after the rock is stripped of its loose 
covering. 

The contractors for the getting of the stone sometimes 
sublet the drilling to men whom they pay at the rate ot 2S. 6d. 
to $s. 6d. per 100 inches. No charging, tamping, or firing, is 
included in this price, and the men are found with tools. It 
will thus be seen that drilling in limestone is easier than 
drilling in granitic, gneissic, or dense slaty rocks. The men 
earn from $s. to 4$. per day. 

i ton 15 cwt. of limestone makes one ton of lime, the rest, 
carbonic acid, sulphur, &c., being driven off in the process of 
burning. 

i ion of South Wales coal, from the district of Swansea and 
Neath, a quality between the anthracitic coal of the west and the 
bituminous coal of the east of that coal-field, will burn four to 
five tons of limestone, but the free-burning coals of North 
Wales and Lancashire will only burn from two and a half to 
three tons. 

These prices do not apply to limestone quarried for build- 
ing purposes, when more attention has to be paid to both size 
and shape. 

Rising higher in the geological scale, we have the mag- 
nesian limestones of Nottingham, York, and Duiham, which 
form hard and durable building stones. 

In the Lias we have in England extensive quarries in its 
layers of limestone in central England, in the district between 
Birmingham and Oxford and Birmingham and Bletchley, as 
well as near Barrow-on-Soar, in Leicestershire. These lime- 
stones are valuable for their cement-making properties. 

In the Oolites we have the Portland limestone and the 
calcareous sandstone, near the base of the series known as 
Bath stone, so valued in the west of England for architectural 
purposes ; the Kenton and Ancaster stone, also from the great 
Oolite, used in ecclesiastical structures in the east of England. 
Of this age is the fine building stone of Caen, a calcareous free- 
stone, and which is also found over large areas of France. 



GLUCINUM. GLUCINA. 3 5 

Of a similar age are the beautiful marbles of Carrara, in 
Italy. The stone has an extensive rane in the Apennines, but 
the best quarries are those of the valleys in the neighbourhood 
of Carrara. 

The best kinds are pure white and crystalline, but the 
general colour is a light blue or white, with bluish veins. 
The stones are quarried up to a large size, ten to fourteen 
feet in length, but large quantities are wasted owing to the 
want of mechanical appliances in the quarries, the stone being 
allowed to fall and tumble a long distance down a rugged rock 
face on heaps of debris. The quarries are supposed to have 
been worked since the first century of the Christian era. 1 

There are a few hard bands near the top of the chalk which 
have been utilized for building, but the mass of this formation 
is too soft for architectural use. Portions of the beds have, 
however, an agricultural value as fertilizers, and there are other 
uses to which the chalk beds have been applied. 

The limestones higher in the series of strata are, as we 
shall see, the sources whence other valuable products are 
obtained, if they are not of so compact and durable a nature as 
some of the older limestones for building purposes. 

GLUCINA. 

Glucina is composed of two parts of glucinum, with three 
parts of oxygen. The metal glucinum is obtained with difficulty 
from its chloride. The process is much the same as that of 
aluminium. The name comes from y/\.wos, sweet, on account 
of the sweet taste of its oxide, glucina. 

The metal is not oxidizable by air or water at the usual 
temperature, but it takes fire in oxygen at a red heat, and 
burns with a vivid light. 

Glucina is of rather rare occurrence, but, as we have seen, 
it enters to the extent of 15 per cent, into the composition of 

1 For a full description of the marble and other quarries of Great 
Britain and foreign countries, the reader is referred to A Treatise on the 
Building and Ornamental Stones of Great Britain and Foreign Countries, 
by Edward Hull, M.A., F.R.S. 1872. 



36 EARTHY AND OTHER MINERALS. 

the emerald, and common emeralds are found in thick crystals 
several feet in length in felspar quarries, in the parishes of 
Kisko, Roslagen, and Tammela, in Finland, from which the 
earth and its metal may be obtained. The minerals containing 
this earth have a specific gravity of 2-7 to 3*75, and with one 
exception leucophane they are harder than quartz, and are 
scarcely fusible before the blow-pipe. 

Z IRC ONI A. 

Seems to be composed of about two parts of zirconium to 
three of oxygen. When obtained from its earth, zirconium 
appears as a powder, which may be compressed into scales 
resembling graphite, and burnished assumes the lustre of 
iron. 

Zirconia occurs in four and eight sided prisms, and also in 
a granular state. Its colour ranges from white to grey, yellow, 
red, brownish red and brown. H. 7-5 and gr. 4-0 to 4*8 ; opaque 
to transparent. Common zircon occurs near Brevik, in the 
South of Norway, and crystals of the mineral occur at various 
places in the United States of America. Among the varieties 
of zircon we must notice the hyacinth, which is a transparent 
red and orange - coloured variety. Jargon or jargoon is a 
nearly colourless variety, with a smoky tinge. Its composition 
is zircon 65, silica 31, oxide of iron 2. It occurs in small 
crystals of four or eight sided prisms, with terminal pyramids. 
In lustre it approaches most nearly the diamond. The 
hyacinth and jargoon are found with other precious stones in 
the sands of Ceylon, already described. Crystals as large as 
walnuts come from Siberia, and fine specimens are brought 
from Greenland. Zircon is found in crystals at various places 
in North Carolina, Vermont, and New York. It belongs to 
the older granitic and gneissic rocks, lavas, and crystalline lime- 
stones. 

THORIA. 

The simple element thorium is the metallic base of thoria. 
It bears a general resemblance to aluminium. It bums in 



COMPOSITION OF LIMESTONES. 



37 



oxygen with an extraordinary degree of brilliancy. It was 
discovered in the year 1824 by Berzelius, in a black lava-like 
mineral, since named thorite after the Scandinavian god Thor, 
on the west coast of Norway. Thorite is black in colour, 
and heavier than the other earths, its gr. being 4-6 to 5-3. 

CHEMICAL COMPOSITION OF VARIOUS LIMESTONES. 





4) U 


|. 


a 


, 






S C 


11 


ll 


^1 


o 

c 




3(1 


1| 


VH ^ 

So 


|| 


1 . 




>> t 


** 


r3 a 


S w 


"j ^ 




iH . 


3 S 
o & 


rt '-2 


|l 


"C "^ 






fc fl 




kS o 






S w 


II 


^"M a 


S^ 


B 




g 

III 

U 


III 


' g S 
^o.S o 


Is 

p 


1 


Carbonate of lime . . 
Carbonate of magnesia . 


86-20 
3-23 


97-520 
0-493 . 


45' 6 
44'4 


26-50 
1798 


95-I6 
1-2O 


Silica . 


2 ' 32 






r i -,/io 




Alumina 
Oxide of iron .... 


1-28 


0-725 


| 


1-32 


0-50 


Organic matter and 












water of combination 


4-66 


0-878 








Alkalies 


I'CQ 










Water and goss . . . 


72 


0-384 




2-80 


1-94 



CHAPTER III. 

CLA YS. 

Clays, how derived and formed Decomposition of Basalt, of Rocks in 
Iceland Brick Clays of the Drift Analyses Clays of the Tertiary 
Strata, Bovey Tracey China Stone and China Clay of Cornwall and 
Devon Comparison with other China Clays Kimmeridge Clay 
Permian Marls and Clays Clays of the Coal-measures Analyses- 
Manufactures of, in North of England, North Wales, Shropshire 
Colouring of Clays and their Products. 

CLAY may be described generally as decomposed silica with 
alumina (the former mineral usually predominating) ; and the 
clays of all ages have been derived ultimately from the wearing 
down and decomposition of rocks already described as con- 
taining these two minerals in their many varieties. But clays 
so derived do not contain all the constituents of their parent 
rocks. Some of these during the process of the chemical 
change we call decomposition have been removed, and by the 
residue an amount of water ranging from 10 to 20 per cent, of 
the mass has been taken up. Some interesting experiments illus- 
trative of this were made by Ebelmen on the basalt of Auvergne, 
both in its unaltered and decomposed state. He found that 
in the process of decomposition there had been removed of 
the original constituents two-thirds of the silica, nine-tenths of 
the iron, which was protoxide in the original and peroxide in 
the decomposed rock, one-half the lime, -nro-ths of the mag- 
nesia, and five-sixths of the potash and soda, together equal 
to 43 per cent, of the basalt. The alumina alone remained 
undiminished, a quantity of water having become united with 
that and with the other residual elements of the rock. 



FORMATION OF CLAY. 39 

It has been found that the decomposition of the silicates of 
rocks (whether igneous or sedimentary) has been effected by 
means of oxygen and carbonic acid, the latter decomposing the 
silicates, and the former changing the protoxide into peroxide. 
Silica is readily soluble in water containing alkaline carbonates. 
It is also soluble in pure water, and in water charged with 
carbonic acid. Lime and magnesia are also soluble in water 
charged with carbonic acid. 

The water flowing through the crevices and interstices of 
the earth's crust is so charged, and as in some places the waters 
of the sea and lakes are now so charged, so through past ages 
there have been times and places where the waters of seas and 
lakes have been so charged with carbonic acid. Hence by pro- 
longed action the rocks in contact with these waters have had 
their silicates dissolved, the latter entering into new combina- 
tions, sometimes, indeed, as nearly pure silica, but usually with 
the alumina set free from the dissolved rocks, and with portions of 
the water forming clays. An illustration of the active and rapid 
decomposition of rocks occurs in the volcanic sulphur districts of 
Iceland, where various gases on their eruption from the earth 
decompose the surrounding rock (palagonite, a hard, reddish- 
white vitreous rock), and changes it into masses of clay of 
various colours according to the amount of iron and other 
minerals it contains. 

Beds and irregular deposits of clay occur in all the groups 
of strata from the most recent down to the base of the Coal- 
measures. Thin layers and pockets occur in the underlying 
millstone grit. The softer layers of the carboniferous Limestone 
and of the underlying Devonian partake more of a shaly and 
marly nature. When we reach the Silurian and Cambrian, 
apart from clayey matter filling cracks and interstices with 
some thin beds in the Upper Silurian, it would seem as if what- 
ever deposits of clay had been found in those early ages had 
again by heat and pressure become hardened into rock. Possibly 
the purer and finer kinds of felspathic rocks, such as those 
which in this country and in Norway and Sweden are quarried 
for porcelainitic purposes, represent these ancient clay beds. 



40 EARTHY AND OTHER MINERALS. 

Let us now notice the nature and uses of the various deposits 
of clay in stratigraphical order, beginning with the newest and 
uppermost. 1 

Starting with the north-west side of Britain, we find a 
thick deposit of gravel, sand, and clay covering the various 
rocks. Lying over nearly the whole of these deposits there is 
spread a thick covering of clay with boulders, known as the 
upper boulder clay. In hollows lying on the surface of this 
clay there are deposits of finer clay which has been washed 
out of the boulder clay, and has been redeposited comparatively 
free from stones in the hollows which at one time contained 
deep still water. It is of this clay, which is of a reddish yellow 
colour, that the surface bricks of the Welsh border counties are 
made, as well as many of those manufactured in Lancashire. 
These burn of a bright red colour. Many examples of these 
deposits may be seen in the brickyards between Chester and 
Oswestry. 2 

Where these clays spread over the Triassic strata, as near 
Shrewsbury, they become much redder in colour. The follow- 
ing analysis will show the general composition of these super- 
ficial clays: 

I 2 3 

Silica 66-68 . . . 49-38 . . . 57-83 

Alumina 26-08 . . . 34-26 . . . 20-55 

Oxide of iron ... 1-26 ... 7-74 . . . 7*75 

Oxide of manganese tr ices 

Lmie 0-84 ... 1-48 ... 1-68 

Magnesia trace ... 5-14 ... 0-97 

Potash 3-87 

Soda 0-56 



1 The reader will find much important and interesting information in 
* The Source of the Materials composing the White Clays of the Tertiaries,' 
by George Maw, Esq., F G.S. Quarterly Journal Geol. Society, vol. 
xxiii. p. 387, etseg. Also Catalogue of Specimens of the Clays and Plastic 
Strata of Great Britain, exhibited in the Museum of Practical Geology, 
London, by the same author. 

2 See The Diitt ot the North Wales Border,' by D. C. Davies, F.G.S. 
Proceedings, Geologists' 1 Association, vol. iv. 



PORCELAIN CLAY OF CORNWALL. 41 

I 2 3 

Carbonic acid 0-90 

Phosphoric acid traces 

Organic matter 4-39 

Water 5-14 . . . i'9j. . . . 2-13 

In the valleys of Wales a dark blue clay underlies the sand 
and gravel deposits, and it is probably derived by washing 
from the blue and grey slaty and shaly rocks that prevail in 
that country. A similar deposit is described by Mr. Maw as 
occurring underneath the alluvium of the Severn Valley, near 
Bridgenorth. 

Underneath all the driftal deposits there are in North Wales 
and on the borders, nestling in hollows and troughs in the 
carboniferous limestone and millstone grit, numerous deposits 
of fine white clay which have evidently been dissolved out of 
the adjacent rocks, the lime having been carried off and in 
some cases deposited as tufa in the immediate neighbourhood. 
The white clays of Nant-y-Garmer, near Llandudno, and of 
Halkin and Mold Mountains, occurring in pockets and irregu- 
lar masses, are examples of these. The red and dark marls 
and shales of the limestones have also contributed to these 
clays, examples occurring in the red clay of Nant-y-Garmer, 
Llandudno, and in the dark clay of Llanferris, near Mold. 

The China or Porcelain Clays of Cornwall. Although derived 
from rocks of a different nature and age, these deposits may be 
grouped from their similarity of origin and position with those 
just referred to. The china clay trade of Cornwall is of com- 
paratively recent date. It appears to have originated with 
Mr. William Cookworthy, who opened a pottery at Plymouth 
in the year 1733, at which he worked some of the clays of 
Devon. In 1755 he found a stone near St. Stephen's, the 
present china stone, which he used for forming a glaze upon 
the porcelain. In 1774 Cookworthy sold his patent to 
Richard Champion, a Bristol merchant, and the works were 
removed to that city. Soon afterwards the works were trans- 
ierred to Tunstall, in Staffordshire, where the business grew 
and flourished, the clays and stones of Cornwall thus finding 



42 EARTHY AND OTHER MINERALS. 

their way to the Staffordshire potteries. The largest deposits 
of china clay in Cornwall are found in the neighbourhood of 
St. Austell and St. Stephen's. There are also other deposits in 
the eastern part of the county, at Blisland and St. Breward, near 
Bodmin, and also near Helston on the west. From the 
St. Stephen's and St. Austell district there were exported to the 
potteries in the year 1809, 1,757 tons; in 1810, 1,888 tons ; 
in 1811, 2, 086^ tons; and in 1812, 1,252 tons. Besides the 
exports to Staffordshire there were sent to the china manufac- 
tories of Worcestershire, from March, 1816, to March, 1817, 
1,775 tons - By the year 1826 the trade had grown so that a 
total of 7,538 tons were shipped that year from Cornwall, 
the points of production having also extended to other places, 
the district of St. Austell and St. Stephen's, however, supplying 
7,090 tons of the amount. In 1838 the production of china 
clay in Corn wall was estimated at 7,600 tons per annum. The 
production in the year 1880 was 278,572 tons, and in 1881 
241,658 tons. In addition to this the production of china 
stone, which in 1838 was estimated at 5.000 tons, was in 1880 
34,870 tons, and in 1881 30,479 tons. Besides these quantities 
there were also raised in Devonshire, from a different deposit 
for the most part, in 1880 25,370 tons, and in 1881 39,067 tons. 
The price of the china stone delivered free on board ship is 
from 30.5-. to 4os. per ton, that of the china clay about 25^. per 
ton. The royalty payable to the landowner on both is from 
2s. 6d. to 4.$-. per ton, a rather heavy royalty. The poor-rates 
amount to 8^. per ton. 

The china clay has been derived from the decomposition 
and wearing down of the granitic rocks in the neighbourhood 
of the deposits, especially of those parts which yield most 
readily to those atmospheric and aqueous influences referred to 
at the commencement of this chapter. The materials have 
been redeposited in adjacent hollows and flats, and in some 
cases where the rock has been crossed and reticulated by veins 
or lodes, the decomposed material remains in its original 
position. An example of this occurs at the Carclaze pit, 
situated about two miles north-east of the town of St. Austell. 




COMPOSITION OF VARIOUS 

It is one of the largest open excavations for clay in Corn 
being about 14 acres in extent. Tin has been mined here as 
in an open stockwerk for several centuries. The tin was found 
in numerous veins from 2 in. to 2 ft. wide, that traversed in 
every direction a decomposed granite of a whitish colour. 
The quarry is now worked almost exclusively for clay. 

When quarried the clay is separated from the coarser mate- 
rials with which it is associated by washing. It is placed on 
either a natural or artificial gently inclined plane. A stream 
of water falls upon it from the height of a few feet, which 
gradually washes it away. The larger fragments are caught upon 
gratings. There are dams placed at distances of 20 ft. or so 
apart, which also intercept the heavier materials. The liquid 
then flows through a series of tanks, until at last only the very 
fine clay remains. This bears the proportion of i ton to every 
8 tons quarried. It is cut into lumps of convenient size, is 
dried, formerly without the application of artificial heat, but 
now this is frequently used, and when it is sufficiently hard to 
bear removal the clay is ready for sale. The wages of the men 
averages 2S. 6d. per day of 7^ hours. There are about 100 
clay works in Cornwall, employing about 1,600 workmen. 

The composition of St. Stephen's china clay is given as, 
silica 39*55, alumina 38*05, water 12*50, magnesia a trace, 
with an insoluble remainder of 870, probably chiefly silica. 
An analysis of china stone from the parish of St. Roche shows 
its composition to be silica 63-17, alumina 20-89, peroxide of 
iron 0-14, lime 0*90, magnesia 0-2 1, potash 11-48, soda 3-11, 
total 94*90. It will be seen that in the clays the potash and 
soda, with portions of the silica, have been removed. 

It may be interesting here to compare the composition of 
the china clay of Cornwall with other clays used in the manu- 
facture of porcelain. 

Original kaolin 1 of China. Silica 76, alumina 17, potash 

and soda 6 (the water previously 
removed). 

1 Kaolin, a corruption of Kauling, a high ridge the name of a hill 
near Jauchau Fu, where the mineral is obtained. 



44 EARTHY AND OTHER MINERALS. 

Original kaolin of Japan. Same as above, only with less 

alkalies. 

Kaolin or porcelain clay from Silica 43*6, alumina 37'7, per- 

Schneetxrg. oxide of iron 1-5, water 12-6. 

Kaolin from Seilitz, Saxony, after Silica 54, alumina 44, potash trace, 
water was expelled. 

KaoLn from Mori, near Berlin. Silica 71*4, alumina 26-0, lime 

and potash traces. 
,, St. Yriex, France. Silica 46-8, alumina 37, water, 

13, potash 2-5. 

,, Dartmoor, Devon. Nearly identical with the fore- 

going from St. Yriex. 

To the foregoing I may add the Silica 48-2, alumina 28-2, mag- 

composition of the fine red clay, of nesia 6 to 7, peroxide of iron 5, 
which the North American Indians carbonate of lime 2 '6, oxide of 
make their pipes, and named after manganese 0-6, water 8-4. 
the adventurous traveller, Mr. Cat- 
lin, Catlinite. 

Where felspar can be found of sufficient purity it is quarried 
for pottery or porcelain manufactures. This is done as already 
stated in Cornwall, and considerable quantities are imported 
into this country from Sweden and Norway. In Ireland, too, 
the beautiful porcelain of Fermanagh is obtained from the 
red felspar found in the vicinity. When burnt this felspar loses 
its colour and becomes white, and the metallic iron, from 
whose presence the colour was derived, is separated from the 
powdered felspar, when it is mixed with water, by means of 
magnets. 

Among the clays of the Tertiary strata especial reference 
may be made to those of Bovey Tracey, referred to in Chap- 
ter XII., as associated with the bituminous deposit of the 
same place, and which form an important source of the clays 
exported from Devonshire for pottery purposes. 

These clays are divided into several kinds according to 
their colour, texture, and the chief purpose for which they are 
employed. There are the * best pipe clay/ the ' cutty clay,' 
the ' household clay,' which is used for whitening stone steps 
and pavement ; the ' stoneware clay,' employed in the manu- 
facture of stoneware ; the * alum makers' clay,' used for 



TERTIARY CLAYS OF DORSETSHIRE. 45 

pottery purposes and the manufacture of alum; the 'drain- 
pipe clay,' used in the manufacture of drain-pipes and for 
other common purposes ; it is stained with iron ; the { blue 
ball clay,' which burns to a pale colour, and is extensively used 
for earthenware purposes in the potteries, and which shows on 
analysis the following composition : 

Silica 47-0 

Alumina 48-0 

Oxide of iron 1-5 

Magnesia 2-0 

\Vater and waste . . . . 1*5 

lOO'O 

The ' black ball clay,' the dark colour of which is probably 
due to the presence of carbonaceous matter ; the * brown ball 
clay,' employed for pottery purposes (composition on analysis 
shows two-thirds silica, one- third alumina, with traces of mag- 
nesia, oxide of iron, and carbonaceous matter) ; the 'black car- 
bonaceous clay.' This clay in its natural state contains 13 per 
cent, of carbon, and the coarser kinds 33 per cent. It burns to 
extreme whiteness, which is believed to be due to the reduction 
of the sesquioxide of iron it contains in the kiln by reaction 
with carbonaceous matter. 

Lower down still in the Tertiary strata are the clays worked 
near Wareham, Dorsetshire. These consist of a ' red plastic 
clay,' which is used to a small extent in the manufacture of 
encaustic tiles ; ' white clay,' which fires of a light cream- 
colour, and is employed for various pottery purposes ; ' 7 clay,' 
also employed for pottery uses, and is remarkable, with the 
following, occurring at the same place, for its great con- 
traction in the kiln ; ' black clay,' coloured with carbona- 
ceous matter which burns out in the kiln; 'blue clay,' con- 
taining about 60 p^r cent, of silica, 34 of alumina, 2 of potash, 
with small amounts of oxide of iron and water of combination ; 
' yellow clay ' of a bright yellow colour, due to the sesquioxide 
of iron being hydrous. It is associated with the blood-red 
plastic clay first named. These two clays are used in the 



46 EARTHY AND OTHER MINERALS. 

manufacture of encaustic tiles and are worth from js. to los. 
per ton free on board at Poole harbour. 

There are various beds of clay in * the London clay ' worked 
near Harwich, Bognor, Arundel, and others interstratified with 
the cretaceous Wealden and Purbeck strata which are locally 
worked, among which may be named the ' fullers'-earth ' of 
the Sandgate beds of the Lower Greensand. This occurs 
between Red Hill and Nutfield, Surrey. It also occurs near 
Maidstone in Kent, Woburn in Bedfordshire, and near Max- 
ton, in Scotland. The fullers'-earth of Surrey is composed 
of silica 53, alumina 10, iron peroxide 9*75, magnesia 1*25, 
lime 0*5, and water 24-0. In the Oolitic series among other 
clays there is the well-known Kimmeridge clay, used for 
making coarse pottery and bricks, and which, in addition to 
silica and alumina, contains protoxide of iron 2 - oS, sesquioxide 
of iron 4*32, bisulphide of iron 1-42, carbonate of lime 4-28, 
and sulphate of lime 5*34, with crystals of selenite distributed 
throughout the mass of the strata. 

Passing by the Oxford and other clays of the Oolite and 
those of the Liassic, Rhaetic, and Triassic strata, some of which 
are of local importance, we come to the red marls of the Per- 
mian, which form the base of important and extensive in- 
dustries in Denbighshire, Shropshire, and Warwickshire. These 
marls form the middle division of the Permian strata. They 
are, in Denbighshire and the contiguous parts of Shropshire, 
about one hundred and fifty yards in thickness. They are of 
a deep red colour, but contain nests and irregular patches of a 
light green, greenish grey, and buff colour. These patches are 
carefully separated from the mass in quarrying, especially for 
the finer kinds of work. The quarries are deep open excava- 
tions, from which the clay is usually drawn up an inclined plane 
to the highest point of the works, whence, after it has been 
crushed, ground, and duly mixed, it is distributed over the 
works for the various processes it has to pass through. The 
red portions, containing most oxide of iron, burn of a deep red 
colour, although the presence of the alkaline earths in clays 
containing most iron will cause the product to be of a lighter 



CLAYS OF THE PERMIAN AND COAL-MEASURES. 47 

colour. There is scarcely any limit to the uses to which 
these clays are put bricks, flooring and roofing tiles, drain- 
pipes, terra-cotta work, cornices and architectural mouldings 
and decorations of all sorts. A visit to the works of Mr. J. C. 
Edwards, Penybont, near Ruabon, or to those of Messrs. 
Maw, near Brosely, will show the extent to which, by means 
of chemical knowledge and long experience, the clays are 
made use of for many purposes. The works in connection 
with the Hockley Hall Collieries, near Tamworth, are also well 
worth a visit, presenting as they do the example of works 
skilfully laid out for producing the largest results at the smallest 
cost. 

Besides 80 per cent, of silica and alumina, the red portions 
of these marls contain : 

Water of combination . . . 279 

Sesquioxide of iion .... 3-23 

Protoxide of iron . . . . 1-35 

Bisulphide of iron .... O-O2 

Carbonate of lime .... 4-15 

Sulphate of lime o-ij 

Alumina ...... 3-95 

Magnesia 2-17 

Alkalies and loss . . . . 1-22 

In the light-coloured patches the proportion of iron is : 

Sesquioxide . ' . . . . i'8i 

Protoxide, so'uhle . . . . 0-60 
Protoxide, insoluble * . . 0-88 

3-29 

Some examples of the red portions contain from 7-54 to 8-64 
of sesquioxide of iron, the lighter colour of the green and 
grey patches being due to the smaller quantity of iron in their 
composition. 

The Clays of the Coal-measures. Underneath most of the 
beds of coal in the British, as well as other coal-fields, there is 
a bed of clay varying from i to 18 feet in thickness. At the 
base of the Permian the red colour for the most part ceases, 
and is replaced by clunch, or clay of a blue, yellow, or pale butf 



EARTHY AND OTHER MINERALS. 



colour. The light-coloured clays, from the quantity of silica 
they contain, as well as from their freedom from impurities, 
have great fire-resisting properties, and are known as fire- 
clays. During the last and present centuries a large industry 
has grown up in the use of the clays of the Coal-measures for 
various purposes, more especially in connection with the north 
of England, Flintshire, Denbighshire, Shropshire, and Stafford- 
shire coal-fields. 

In the north of England the manufacture of earthenware 
was started about the year 1830, and that of fire-bricks and fire- 
clay goods generally, first started on the Tyne, about a hundred 
years ago. The clays under different coal seams possessing 
different properties, and all of them being capable of being 
worked from the same mine if deemed desirable gives great 
facilities for the manufacture of widely different goods at clay 
works established in connection with a colliery. Mr. Joseph 
Cowen, M.P., gives 1 the following analyses of samples of fire- 
clay from seven beds underlying coal in the neighbourhood of 
Newcastle-upon-Tyne : 





i. 


2. 


3- 


4- 


5- 


6. 


7- 


Silica . . 


51-10 


47-55 


4855 


5 I-II 


71-28 


83-29 


69-25 


Alumina . 


3'*35 


29^0 


30-25 


30-40 


17-75 


8-10 


17-90 


Oxide of iron 
Lime . . 


4-03 
1-46 


I'34 


4-06 

1-66 


1-76 ] 


2 '43 ) 

> 


188, 


2-97 
T "jr* 


Magnesia . 


!*54 


0-71 


1-91 


trace 


2-30) 


2 99 J 


i 30 


Water and or- 
















ganic matter 


10-47 


12-01 


10-67 


12-29 


6-94 


3-64 


7-58 



The fire-clays those containing the most silica are made 
into bricks for lining furnaces, sanitary tubes, gas-retorts, archi- 
tectural ornaments, and many other articles which the modern 
requirements of science, sanitation, and manufactures demand. 

Passing south-west to the North Wales and Shropshire coal- 
field, the following remarks from a paper of mine published a 

1 The Industrial Resources of the Tyne, Wear, and Tees. Newcastle, 
1864. 



STRATA OF THE NORTH WALES COAL-FIELD. 49 



few years ago, 1 may serve to describe both the growth of the 
industry and the purposes for which the various clays are used. 
The following is a very general section of the order and 
position of the principal coal-seams of North Wales and the 
contiguous part of Shropshire, and its perusal will enable the 
reader to understand the subsequent allusions to the different 
clays and works of the district : 

f Dark Red Sandstones. 

) Saint Martin's Coal-measures ..... 

Red marls ..... / 

^> Grey and green rocks and conglomerate . 

Upper coal-measures ...... 

Middle sandstones, shales, and coals, including the 
freestone known as the Cefn, Minera, or Hollin 
sandstone ........ 140 



Upper 
Middle 
Lower 

Upper . 
Middle . 



Lower 



Yds. 
90 

112 

130 

90 



Cefn Coal. 
Clays, shales, and thin coals 

Dirty or Drowsal Coal. 
Strata as under Cefn coal . 



Strata as before 
Strata as before 
Strata with coals 
Strata 



Quaker Coal. 



Main Coal. 



Upper Yard Coal. 

Lower Yard Coal. 

Wall and Bench Coal. 



Strata 



Strata 



Strata 



Millstone grit. 



Lluvynenion or Half Yard Coal. 
Chwarele Coal. 

Lowest Coal. 
Add thickness of coals 

Sandstones. 



Yds. 

IOO 

60 
25 
14 

70 

18 

35 
35 
25 



292 

12 

866 



The clays of the ' Coal-measures ' are usually denominated 

1 ' The Fire-clays and Fire-clay Productions of North Wales,' British 
Architect, Jan. 2ist and 28th, 1877. 

E 



50 EARTHY AND OTHER MINERALS. 

' fire-clays.' Their power of resisting the action of fire is, 
however, very variable. The best adapted for this purpose are 
those that contain the largest proportion of silica, and that are 
free from any admixture of the oxides or sulphides of iron. 
Even the best of them have their fire-resisting quality increased 
by the addition of sand from the beds of the millstone grit ; 
indeed, the bricks made from the ' gannister ' beds of that 
series are the most largely used in the manufacture of iron 
and steel. Mr. Thomas Barnes, of the Quinta, and Mr. J. C. 
Edwards, of Trefynant, have both of them made some inte- 
resting expeiiments in the admixture of these sandstones with 
the clays worked by them. 

We now turn to the notice of the principal brick and tile 
works of the district, and we find that among the earliest works 
of the kind were those of the late Mr. Howell, known as 
' The Pottery/ at Trefonen, south-west of Oswestry. The 
writer remembers these in active work forty years ago, and at 
that date the proprietor had discovered the adaptability of the 
clays to the manufacture of pipes, tile-crests, chimney-tops, 
and many of the other purposes for which, since then, they 
have been more extensively used. 

The chief clay worked at Trefonen was the one underlying 
the four-foot coal of the locality, and which corresponds to the 
Quaker coal of the section. These works were closed about 
twenty-five years ago, when the bulk of the trade was removed 
to the works of the late Messrs. Croxon, at Sweeney, south 
of Oswestry. The manufacture of fire-bricks, tiles, and drain- 
pipes has been largely carried on at these works until now, and 
recently, the concern having changed owners, the present com- 
pany the Oswestry Coal and Brick Company have made 
extensive additions to the works, to meet the requirements of 
an increased business. 

Two clays chiefly are used here, the one under the ' four- 
foot coal ' as at Trefonen, and that under the ' black shale 
coal,' a coal answering to the ' Drowsal coal ' of the section. 
It was from an old pit-heap composed largely of these clays 
that the bricks used in the construction of the Oswestry 



BRICKWORKS OF PENYBONT. 51 

sewage works were made. The clays themselves yield a 
nearly white brick, that looks well in a building, although, 
perhaps, the absence of warmth of colour may, to some tastes, 
be a defect. The owners have, however, on their property a 
thick deposit of the 'red marls,' and by a judicious mixing of 
these with the white clays good results may be obtained. 

A very important work, full of good machinery and con- 
nected with a railway, was some years ago carried on by Mr. 
Thomas Savon at Coedygo, midway between the two former 
works. It is now closed, and every vestige of it removed, the 
owner of the freehold, it is said, objecting to such works as 
spoiling the rurality of the neighbourhood. 

Six miles to the north of Sweeney are the brick-works of the 
Quinta Colliery and Brick Company. The clay of the ' yard 
coal ' was worked here for some years ; but latterly the under 
clay of a lower coal, probably that of the ( lower yard,' has 
been substituted. The former clay contained an appreciable 
quantity of oxide of iron, which occasionally gave a reddish 
tinge to the bricks. An improvement has ensued with the 
working of the lower clay, and a nice sound brick, with rather 
more colour than those of Sweeney, is the result. The manu- 
facture here is not confined to bricks, but includes pipes, 
tiles, &c. 

Three miles farther north, and situated on a promontory 
formed by the windings of the river Dee, we reach the Peny- 
bont Works, belonging to Mr. J. C. Edwards, of Trevor. The 
clay used at these works is obtained in an open excavation from 
the ' red marls ' of the Permian, near the top of the section. 
Following the colour of the clay, the bricks and other produc- 
tions at these works are of a deep red colour. Perhaps a 
better red brick, smoother, more uniform in texture and 
colour, and more impervious to moisture, is not produced than 
the best pressed bricks from the clays of these works. In 
addition to bricks, the manufacture of blue paving- tiles is 
largely carried on, as well as that ot roofing-tiles, for which, 
owing to the scarcity of roofing-slates, and the revived taste 
for red-tiled roofs, there is a good demand. Other articles, 



52 EARTHY AND OTHER MINERALS. 

such as crests, pipes, flooring-tiles, &c., are also extensively 
made here. 

About a mile and a half higher up the valley of the Dee 
are Mr. Edwards's older fire-clay works, at Trefynant, which 
may be briefly described as among the most complete works of 
the kind in North Wales. The clay used is that underlying 
the ' Llwynenion,' or ' Half-yard coal.' This clay is many feet 
in thickness. The underground workings are extensive, and 
the coal is left in the ground to form a roof for them. 

The productions are of a pale buff colour, of great uni- 
formity of appearance. Mr. Edwards has, from time to time 
during a long course of years, added the manufacture of 
chimney-tops, socket-pipes, junctions, and of all kinds of 
sanitary ware, to the glaze and finish of which he has given 
much attention. 

Of a very similar kind, and deserving of much the same 
remarks, are the more recent works of Mr. Bowers and of Mr. 
Seacombe, nearer to the village of Ruabon. 

These gentlemen, with Mr. Edwards, have hitherto been 
the chief producers of sewage, drainage, and sanitary appliances 
in North Wales. The bricks from all the works command a 
large sale. 

A little farther to the west of the Trefynant Works we are at 
Garth Trevor and on the lower edge of the Coal-measures. 
Here, from the shaly and iron-stained clays and sandstones 
that lie between the Chwarele and lowest coal, Mr. Charles 
Mason produces large quantities of good sound and serviceable 
cherry-red bricks, which are well adapted for all ordinary 
building purposes. The clay of the * Chwarele coal ' occurs 
abundantly on this property. Its productions are of much the 
same character as those of the Llwynenion clay, and it is well 
adapted for ordinary pottery use. It has not, however, as yet 
been worked to any extent by Mr. Mason, as it has in the ad- 
joining ' Chwarele Works,' of which little can be said just now, 
except that, through the vicissitudes of trade, operations were 
recently suspended. 

Up the hill to the north, and situated about two miles to 



BRICKWORKS OF BUCKLEY MOUNTAIN. 53 

the west of the village of Ruabon, are the more recently 
developed works of Messrs. Smith and Thomas, at Plas Ucha. 
This firm works the clays associated with the ' wall and bench ' 
seams of coal, which here are adapted for use, and yield good 
bricks of a pale yellow colour that are rapidly rinding their way 
into the market. 

More recent still are the works at Plas-yn-wern, the pro- 
perty of Mr. G. H. Whalley, M.P., and which promise to be 
among the most extensive of the district. Various clays, 
from the ' Quaker ' downwards, are intended to be used at 
these works. 

At Ponkey, farther north, good hard pale red bricks are 
made from the clays in the refuse heaps of old coal-pits, and 
one or two works are in the early stages of growth. 1 

A stretch of six or seven miles brings us to the very edge 
of the Denbighshire coal-field, where it is separated from that of 
Flintshire by the limestone and grit hills of Hope and Caergwrle 
Here are the Llay Hall Colliery and Brick Works, which are just 
being brought into shape, and where, in addition to the use of 
the clays from the lower coal-seams, the owners intend to work 
the series of clays and shales that lie in the middle series 
between the ' Cefn ' or ' Minera sandstone,' and the ' Cefn ' or 
stinking ' coal. 

The mention of these shales and clays, and a walk of a few 
miles across the dividing hills, brings us to the old and great 
brickmaking region of Buckley Mountain. The works on and 
about the ' mountain ' are very numerous, and among the 
oldest are those belonging to Mr. Hancock and Mr. Catherall. 
Great open excavations meet us at almost every turn. These 
are dug in the shaly clays just alluded to as underlying the 
* Cefn ' or ' Minera sandstone,' which here is known as the 
6 Hollin coal rock,' or sandstone. Immediately underneath 
this rock is a thick deposit of rocky clay, which, mixed with a 
little of the purer clays, makes a good common brick. Next 
below is a series of blue and yellow clays, which yield good 

1 As these pages are passing through the press, most extensive terra- 
cotta and brick works are being erected near Ponkey, 



54 EARTHY AND OTHER MINERALS. 

bricks of a pale red colour. Lower down is a dark clay, which, 
when burnt, loses its dark carbonaceous colouring matter, and 
gives a nice pale-coloured fire-brick. 

Underneath the whole of the above clays there is on the 
' mountain ' a bed of fine yellow clay, which has long been 
used for the common, though useful, kind of pottery ware for 
which the place is famous. A bed of the same character, and 
occupying just the same position, has also been worked for 
many years at Cefn, near Ruabon. 

On the northern slope of Buckley Mountain, and lying 
between it and the river Dee, is the Aston Hall Colliery and 
Brick Works, on the property of the Right Hon. W. E. Glad- 
stone, M.P. A beautiful rich-coloured yellowish brick is 
made here from the clays of * wall and bench coal,' as at Plas 
Ucha, near Ruabon. These bricks may be seen to advantage 
in some of the best buildings at Rhyl and other towns on the 
north coast of Wales ; they form a nice contrast to and in 
combination with the dark red bricks from the * red marls ' at 
Penybont. 

Since the foregoing remarks were written, changes have 
taken place in the ownership of the smaller works ; but 
Edwards's, Bowers's, and Seacombe's remain in the same 
hands. At the Sweeney Colliery the red clay referred to has 
since been opened upon and worked with considerable success. 

The clays of the Coal-measures are hard, and are usually 
mined by cutting away the foot and boring in the top of the 
seam for blasting. The price paid to the getters varies from 
is. 8d. to 2s. $d. per ton, according to the hardness and thick- 
ness of the seam. In most cases the newly-obtained clay is 
laid out conveniently upon the surface for weathering before it 
is used. The purer yellow and buff clays are much mixed in 
the district with the red clays of the Permian in the manufac- 
ture of encaustic tiles. 

The clays most used in the South Shropshire coal-field are 
the following : 

A red marl occurring from 20 to 30 yards above the ' sul- 
phur coal ' at Broseley Green. This is about 5 ft. thick, and 



CLAYS OF THE SOUTH SHROPSHIRE COAL-FIELD. 55 

it is extensively employed at the Messrs. Maws works, in asso- 
ciation with more refractory clays, in the manufacture of 
encaustic tiles. The red portion of the clay contains up to 
8*64 of iron ; it burns of a dull red colour. Its composition is 

as follows: silica | ^ blned [ 2 ^.' 71 ] 64-06, titanic acid 0-62, 

alumina 2 '60, sesquioxide of iron 6*84, protoxide of iron 
0-32, protoxide of manganese 0-09, lime 0-12, magnesia 
0*04, potash 0*91, soda 0*44, water, with traces of organic 
matter, 5-85. The brick clay, occurring about the middle of 
the Coal-measures as a bed from 8 to 12 ft. thick, and is 
extensively used in the manufacture of the celebrated brown 
Broseley bricks. The Pennystone Mount, which forms the 
matrix of the Pennystone ironstone at Benthall, Broseley. It 
is 6 ft. thick, and has nodules of carbonate of iron in the upper 
part ; it is grey in colour, and of a rich ochreous brown after 
burning. It is used in the manufacture of encaustic tiles. 
Two-foot coal fire-clay, worked at Benthall, Broseley. Colour, 
dark grey ; burns of a pale buff or cream colour. It is used in 
the manufacture of fire-bricks, common * yellow ware ' pottery, 
and encaustic tiles. 

' Ganie coal fire-clay,' in the lower Coal-measures, about 
2 ft. thick, of a grey colour, and burns of a pale buff or cream 
colour. It is one of the most refractory clays of the Shropshire 
coal-field. It is employed in the manufacture of bricks and 
encaustic tiles. 

The clays of the three coal-fields already described may be 
taken as representative of those obtained from the other British 
coal-fields, from the whole of which there was produced of clay 
in the year 1881, as returned to the inspectors, 1,896,907 tons. 

With its wealth of mineral resources, America possesses 
an abundance of clays of various kinds, which are gradually 
being utilised. The same remark is true of the Coal-measures 
and other clays of various countries ; but the foregoing de- 
scription of the clays of Great Britain may be taken as repre- 
sentative of similar deposits in foreign countries. 

The following remarks relative to the colouring of burnt 



56 EARTHY AND OTHER MINERALS. 

clays, by Mr. George Maw, F.G.S., given in the 'Catalogue of 
British Clays/ to which I am indebted for much information, 
are interesting and valuable, the more so since they are the result 
of much investigation and practical experience. 

' The colour of burnt ferruginous clays is entirely due to 
the amount of iron present, irrespective of its previous state of 
combination, but subject to certain conditions in the general 
composition of the clay. The action of the kiln, with some 
exceptions referred to below, is uniform on nearly every state 
of combination in which the iron occurs, viz. to reduce it to 
anhydrous sesquioxide, associated as silicates in a more or less 
intimate state of combination with the other silicates developed 
in burning. 

' Yellow clays coloured with hydrous sesquioxide, e.g. yellow 
ochre, and red clays coloured with anhydrous sesquioxide and 
the lower hydrates, merely lose their water of combination and 
become bright red bricks. 

' Grey clays, containing finely divided pyrites or bisulphide 
of iron, are also converted by the kiln into bright reds, the 
sulphur being driven off, leaving the terra-cotta charged with 
the red anhydrous oxide. 

' In clays charged with grey carbonates of iron the following 
reaction takes place. The carbonic acid is driven off as 
carbonic oxide, part of its oxygen peroxidizing the iron. 

'Grey clays containing less than i or i per cent, of iron 
change in the kiln to various shades of cream colour or buff, 
whilst those containing from 2 to 10 or 12 per cent, of iron 
produce in the kiln the bright red bodies used in the manufac- 
ture of terra-cotta, encaustic tiles, red building bricks, &c. 
There seems to be no essential difference, with the exception 
noticed below, in the colouring matter of the clays that burn 
buff and those that burn red in the kiln, the depth of colour 
depending merely on the amount of iron present, the buff shades 
graduating into the deeper shades of red. 

' The brightest shades of red and buff are, however, pro- 
duced with but a partial vitrification of the body. At a heat 
sufficient to insure its complete vitrification a further change of 



COLOUR OF CLAYS AFFECTED BY BURNING. 57 

colour takes place. The bright buff shades are changed to 
neutral greys, and the reds to a slaty greyish black, which 
probably results from a partial reduction of the metallic 
colouring matter, and its more intimate combination with the 
other vitreous silicates produced at the higher temperatures. 
In clays containing a large proportion of carbonaceous matter 
the complete peroxidation and consequent colouring power of 
the iron seems to be arrested. In the black carbonaceous clay 
of Bovey Tracey, containing 13 per cent, of organic matter, 
the combustion of the carbon in contact with the ferruginous 
oxides seems wholly or partially to have reduced them to a 
metallic state or lower oxide having less colouring power than 
the sesquioxide, and a remarkable bleaching of the burnt clay 
has been the result. The presence of the alkaline earths in 
ferruginous clays, especially of lime and magnesia, has also a 
singular bleaching power in the kiln, arresting the development 
of the bright red colour. One of the red marls of the Permian, 
containing 6 per cent, of sesquioxide of iron and 35 per cent, 
of carbonate of lime, burned of a greyish buff instead of the 
rich red such a proportion of iron would otherwise have pro- 
duced. From some experiments made by the writer it has 
been ascertained that as small a proportion as 5 per cent, of 
caustic magnesia mixed with a red clay entirely destroys its red 
colour in the kiln, probably from the production of a pale- 
coloured silicate of iron and the alkaline earth. A familiar 
example of this reaction occurs in the process of manufacturing 
yellow bricks in the neighbourhood of London, the colour of 
which is dependent on the admixture of ground chalk with the 
brick earth, the brick earth by itself burning of a red colour.' 

Clays occur in various degrees of fineness, from the coarser- 
grained clays of the drift to the fine clays of the tertiary beds 
and the Coal-measures. All clays contract in burning, but it is 
found that coarse-grained clays containing most silica contract 
less in burning than fine smooth clays. The amount of con- 
traction is due to the loss of water, the loss of carbonic acid, 
and the consumption of the carbonaceous matter contained in 
the clay. It is also affected by the presence of alkalies, which 



58 EARTHY AND OTHER MINERALS. 

promote the complete vitrification and consequent drawing 
together of the silicious particles. Clays made up also of 
large and small particles contract less than those made up of 
grains more uniform in size, the smaller particles helping to 
fill up the interstices of the larger. The average amount of 
the contraction of clays in burning is from 6 to 7 per cent, of 
the original moulded size of the article. 



PART II. 
HALOID MINERALS. 

(COMPOUNDS OF THE EARTHS AND ALKALIES), 
CHLORIDE OF SODIUM (COMMON SALT), 
NITRATE OF SODA, BORAX, BARYTA, GYPSUM, 
ALUM SHALE, PHOSPHATE OF LIME. 



6i 



CHAPTER IV. 

SODIUM, CHLORINE, CHLORIDE OF SODIUM (COMMON 

SALT). 

Description of Sodium Of Chlorine -Common Salt resulting from the 
Combination of the Two The New Red Sandstone Plains of England 
Stratigraphical Position of the Cheshire Salt Deposits History of 
Salt'working in Cheshire and Worcestershire Strata overlying the 
Cheshire Salt Beds Analysis of Rock Salt Of Brines Details of 
Cheshire Salt-mining Brine Springs of Worcestershire Associated 
Strata Detailed Section of Characteristics of the Brine Statistics-- 
Brine Springs of Ashby Wolds Salt Manufacture in the North of 
England Manufacture of Sulphate of Soda Discovery of a Bed of 
Rock Salt at Middlesborough Detailed Section of Strata Analysis 
of the Rock Salt Second Boring near Fort Clarence with Results 
Rock Salt Deposits of Carrickfergus, Ireland Method of Working. 

SODIUM. 

SODIUM, the metallic base of soda, and one of the simple 
elements, is a soft white metal, with the appearance of silver. 
It was obtained by Sir Humphrey Davy by the voltaic decom- 
position of soda. It may be cut with a knife, and it yields to 
the pressure of the fingers. On exposure to the air it oxidizes 
spontaneously, and when nearly red-hot it takes fire and burns 
with a yellow flame. It passes into a liquid state at a tempera- 
ture of 194. It is largely diffused throughout nature, its salts 
being found in all animal fluids, and, as we have seen, there is 
an appreciable proportion in most of the older rocks. 

CHLORINE. CHLORIDE OF SODIUM. 

Chlorine was discovered by Scheele in 1774, and it was 
considered to be of a compound nature till 1809, when Gay- 
Lussac and Thenard demonstrated that it should be considered 



62 



EARTHY AND OTHER MINERALS. 



a simple substance. Sir 
Humphrey Davy fol- 
lowed up the investiga- 
tion of it shortly after- 
wards, and gave it its 
name from xAwpos, yel- 
lowish green, in allusion 
to the colour of its gas, 
which is also very dense, 
and with a strong, suffo- 
cating odour. Sodium 
takes fire in this gas, 
and combining with 
that element, common 
salt is the result. The 
same result has been 
produced by the union 
of the two elements in 
the sea, and the propor- 
tions in which they have 
combined with each 
other and with other 
substances will be seen 
in the following pages. 
From the summit of 
the Minera Mountain, 
five miles west of Wrex- 
ham, North Wales, the 
spectator has around 
him one of the most 
extensive views in Eng- 
land. Eastwards there 
is the New Red Sand- 
stone plain of Cheshire; 
to the south-west he 
may discern the open- 
ings through which this 






Hi, 



W 



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S'o' 



* 1 

w > 
Cfl 



a 

* S 

55 ^ 

* ^ 

O .-- 

Q 



<CQ 



bo 

c 
J 

i 
^ 
13 

M 

il "* 

H 
& I 



? 

S M -Z 



HISTORY OF THE CHESHIRE SALT DEPOSITS. 63 

geological formation extends down the plain of the Severn to 
Worcester and the Bristol Channel. With a little aid from his 
imagination he realises how the same red rocks to the south- 
east mantle around the southern termination of the Pennine 
Chain of carboniferous rocks, through the counties of Leicester 
and Nottingham, and form on the eastern side of the chain the 
Red Sandstone plains of York and Durham. 

It is on the uppermost division of this strata, as shown in the 
section, Fig. 7, that the great salt deposits of Cheshire are found. 

Before 1 describe the details of the way in which these 
deposits occur, I will give a brief rksumk of the rise and pro- 
gress of the industry. In doing this I am glad to avail myself 
of the help afforded by the information gathered some ten 
years ago by Mr. Joseph Dickinson, F.G.S., one of H.M. In- 
spectors of Mines, and which is embodied in his excellent 
' Report on Land-slips in the Salt Districts/ 

It is clear that the Romans, following in the wake of the 
original inhabitants, worked the salt springs, and among the 
earliest subsequent references to salt springs are those which 
relate to those of Droitwich, in Worcestershire. From these 
it appears that Kenulph, King of the Mercians, in the year 
8 1 6, gave Hamilton and ten houses in Wich the name that 
seems to have been given to places containing salt springs 
to the church of Worcester; and about the year 906 Edwy, 
King of England, endowed the same church with Tepstone 
and five salt furnaces or scales. 

Between the years 1084 and 1086 William the Conqueror 
caused among the other inquiries, the results of which are 
recorded in Domesday Book, one to be made relative to the 
Wichs and salt-houses their names, by whom they had been 
held in the time of Edward the Confessor, the last hereditary 
Saxon king, and by whom they were held at the time the 
inquiry was made. In 1863 Mr. William Beaumont, after a 
painstaking examination of the German text and the numerous 
contractions, gave a zincograph of the original document, 
together with a translation, from which the following particulars 
were collected by Mr. Dickinson : 



64 EARTHY AND OTHER MINERALS, 

'In Roeleau hundred the Earl Hugh holds Wyreham 
(Weaverham) in demesne. Earl Edward held it. A foreigner 
holds of the Earl. There were in Wych seven salt-houses 
belonging to this manor. One of these now renders salt to the 
Hall ; the others are waste. The Earl himself holds Frotesham 
(Frodsham). There is in Wych half a salt-house to supply the 
Hall. 

' In Dudestan hundred, Robert Fitz Hugh holds Beddes- 
field (Bettisfield, Flintshire) of Earl Hugh ; Earl Edwin held it. 
The same Robert holds Burwardestone ; Earl Edwin held it. 
There is a salt-house of 24 shillings. The Bishop of Chester 
claims a hide and a half, and a salt-house in this manor. 

' In Mildestvich hundred the same Richard (Richard 
de Vernon) holds Wice (Leftwich). Osmer and Alsi held it 
for two manors, and were free men. 

' In Warmundestron Hundret. The same William (Wil- 
liam Maldebeng) holds Actune (Acton by Nantwich). This 
manor has its plea in the lord's hall, and in Wich one house 
free to make salt. 

' In Tunundune hundred. The same William (William 
Fitz Nigel) holds Heletune (Halton) ; Orme held it. In Wich 
there is a house waste. 

* In Roelan hundred. The same Gilbert (Gilbert de 
Venables) holds Herford (Hartford). Dodo held it for two 
manors as a free man. In Wich one salt-house rendering 
2 shillings, and half another salt-house waste. 

'In Bochelau hundred. The same Gilbert (Gilbert de 
Venables) holds Wimundesham (Wincham). Dot held it, and 
was a free man. There is one acre of wood and a hawk's aery, 
and one house in Wich, and one border. Randle holds it of 
the Earl Tatune (Tatton) ; Lewin held it. There is a house in 
Wich waste. 

'Mildestvic (Middlewich) hundred. Hugh and William 
hold of the Earl Rode. Godric and Raves held it for two 
manors, and were free men. 

' In the same hundred of Mildestvic there was a third Wich 
called Norwich (Northwich), which was in farm at eight pounds. 



EXTRACTS FROM DOMESDAY BOOK. 65 

In it there were the same laws and customs as in the other 
Wiches, and the King and Earl divided the receipts in the like 
manner. All the thanes who held salt-houses in this Wich 
gave no Friday's boilings of salt the year through. Whoever 
brought a cart with two or more oxen from another shire gave 
4 pence for the toll. A man from the same shire gave for his 
cart 2 pence within the third night after his return home. If 
he allowed the third night to pass he was fined 40 shillings. 
A man from another shire paid i penny for a horse-load. 
But a man from the same shire paid i styca within the 
third night after his return, as aforesaid. A man living in the 
same hundred, if he carted salt about through the country to 
sell, gave a penny for every cart for as many times as he loaded 
it. If he carried salt on a horse to sell he gave one penny at 
Martinmas. Whoso did not pay it at that time was fined 40 
shillings. All the other customs in the Wiches are the same. 
This manor was waste when Earl Hugh received it. It is now 
worth 35 shillings.' 

The next references, which are to Nantwich, are interesting, 
inasmuch as the salt trade has now departed from the locality, 
the last salt being manufactured at Nantwich about the year 
1847. 

'Nantwich. In King Edward's time there was Wich in 
Warmundestron hundred, in which there was a well for making 
salt, and between the King and Earl Edwin there were 8 salt- 
houses, so divided that of all their issues and rents the King 
had two parts and the Earl the third. But besides these the 
Earl had one salt-house adjoining his manor of Acatone 
(Acton), which was his own. From this salt-house the Earl 
had sufficient salt for his house throughout the year. But if 
he sold any from thence the King had twopence and the Earl 
a third penny for the toll. In the same Wich many men from 
the country had salt-houses of which this was the custom : 

' From our Lord's Ascension to Martinmas any one having 
a salt-house might carry home salt for his own use. But if he 
sold any of it either there or elsewhere in the county of Chester 
he paid toll to the King and the Earl. Whoever after Martin- 



66 EARTHY AND OTHER MINERALS. 

mas carried away salt from any salt-house except the Earl's 
under his custom aforesaid, paid toll, whether the salt was his 
own or purchased. These aforesaid 8 salt-houses of the King 
and the Earl in every week that salt was boiled, or they were 
used, on a Friday rendered 16 boilings of salt, of which 15 
made a horse-load. But from Martinmas to our Lord's Ascen- 
sion these boilings were given according to custom as from the 
salt-houses of the King and the Earl. All these salt-houses, 
both of the lord and other people, were surrounded on one part 
by a certain river and on the other part by a river, and on the 
other part by a ditch. Whosoever committed a forfeiture 
within these bounds might make amends either by the pay- 
ment of 2 shillings or by 30 boilings of salt, except in the 
case of homicide or of a theft for which the thief was adjudged 
to die. These last, if done here, were dealt with as in the rest 
of the shire. If out of the prescribed circuit of the salt-houses 
any person within the county withheld the toll and was con- 
victed thereof, he brought it back and was fined 40 shillings if 
a free man, or if not free 4 shillings. But if he carried the 
toll into another shire where it was demanded, the fine was the 
same. In King Edward's time this Wich, with all pleas in the 
same hundred, rendered 21 pounds in farm. When Earl Hugh 
received it, except only one salt-house it was waste. William 
Maldebeng now holds of the Earl the same Wich with all the 
customs thereunto belonging, and all the same hundred, which 
is rated at 40 shillings, of which 30 shillings are put on the 
land of the same William, and 10 shillings on the land of the 
Bishop, and the lands of Richard and Gilbert which they have 
in the same hundred, and the Wich is let to farm at 10 
pounds. 

' Middewich. In Mildestwich hundred there is another 
Wich between the King and the Earl. There, however, the 
salt-houses were not the lord's, but they had the same laws and 
customs that have been mentioned in the above-mentioned 
Wich, and the customs were divided between the King and 
Earl in the same manner. This Wich was let to farm for 8 
pounds, and the hundred wherein it was for 40 shillings. The 



DISCOVERY OF ROCK SALT IN CHESHIRE. 67 

King had two parts and the Earl the third. When Earl Hugh 
received it, it was waste. The Earl now holds it, and it is 
let to farm for 25 shillings and two wainloads of salt. But the 
hundred is worth 40 shillings. From these two Wiches who- 
ever carried away bought salt in a wain drawn by four oxen or 
more paid 4d. for the toll ; but if by two oxen 2d., if the salt 
were two horse-loads. A man from another hundred gave 
2d. for a horse-load. But a man of the same hundred gave 
only a halfpenny for a horse-load. Whoever loaded his wain 
so that the axle broke within a league of either Wich gave 2 
shillings to the King's or Earl's officer, if he were overtaken 
within the league. In like manner he who loaded his horse so 
as to break its back gave 2 shillings if overtaken within the 
league, but nothing if overtaken beyond it. Whoever made 
two horse-loads of salt out of one was fined 40 shillings if the 
officer overtook him. If he was not found nothing was to be 
exacted of any other. Men on foot from another hundred 
buying salt paid 2d. for eight men's loads. Men of the same 
hundred paid id. for the same number of such loads. 

' Flintshire (the detached portion between Cheshire, Den- 
bighshire, and Shropshire). The same Hugh (Hugh Fitz 
Osborn) holds Claventone (Claverton, Cheshire), Osmer held 
it and was a free man. To this manor belong eight burgesses 
in the city, and they render 9 shillings and 4 pence, and there 
is a salt-house in Norwich ( North wich) worth 12 pence.' 

In the year 1245, when Henry III. was at war with the 
Welsh, he caused the brine springs of Cheshire to be destroyed 
in order to cut off the supply of salt to the enemy. In the 
time of Henry VI. there were 216 salt-houses in operation at 
Nantwich. In the reign of Queen Elizabeth there were over 
200 salt-works of six pans each in Cheshire. In 1671 there 
were two salt-works in operation at Winsford. 

Up to this date the whole of the salt made in Cheshire was 
obtained by evaporation from the brine of springs ; but in 
1670 Mr. Adam Martindale communioated to the 'Philosophical 
Transactions' the fact that in that year John Jackson, in 
searching for coal on behalf of the lord of the soil, William 



68 EARTHY AND OTHER MINERALS. 

Marbury, of Marbury, Esquire, brought up natural salt by an 
instrument. This first boring was at Marbury Lane, Marston, 
near Northwich, and it was followed by the sinking of a shaft, 
and the deposit was worked until the year 1720, when the 
shaft fell in. Other shafts were sunk, and the working of the 
rock salt underground at Marston has been continuous until 
now. Up to the year 1779 rock salt was only obtained from 
these mines at Marston ; but in that year explorations were 
made at Lawton, which led not only to the finding of the same, 
but also a lower bed of salt. This discovery led the owners of 
the Marston mine, in the year 1781, to sink a shaft from their 
workings by means of a horse-gin, the result of which was the 
discovery of the lower bed of salt. Explorations have since 
been made to a depth of 60 yards or so in the strata below the 
bottom bed of salt, which show thin beds and irregular sphe- 
roidal masses of rock salt in the marls. These have not yet 
been worked. 

In 1808 brine springs were chiefly confined to the valleys 
of the Weaver and the Wheeloch, with a spring at Dirtwich on 
the borders of the detached part of Flintshire, and a weak 
spring at Dunham, near the river Bollin. 

The most distant point up the course of the Weaver was 
near Andlem. Here a boring was put down through the slight 
covering of lias which went into weak brine. Nearer Nant- 
wich there were then several springs in use. but these have 
been discontinued, partly because the brine was weaker, and 
partly because the facilities for carriage were not so great as at 
other places. The most abundant springs were at Winsford, 
and then at Nantwich and Northwich. Between these two 
places the inflow of fresh water spoils the successful working 
of the brine. Springs of weaker brine have been found down 
the course of the Weaver to Frodsham. 

From remote times salt has been the subject of taxation in 
England. There is a reference to it, we are told, 64 years B.C. 
The tribute was continued by the Romans when they worked the 
Droitwich salt springs, and they partly paid the wages of their 
soldiers in salt.. Hence, it is said the origin of the custom at 



SALT IN CHESHIRE AND WORCESTERSHIRE. 69 

the Eton Montem of asking for salt. Writing in the last 
century, Dr. Johnson defined this impost to be a hateful tax on 
commodities not adjudged by the common judges of property. 
At the beginning of the present century it was computed that 
800 tons of salt were wasted annually at the Ashby de la 
Zouch springs in Leicestershire, because of the tax upon salt, 
which precluded the possibility of evaporating the brine with 
the small coal, which was thus also wasted. About the same 
period the amount of taxes paid by the salt-works of Cheshire 
and Worcestershire ranged from i,8oo/. to 20,ooo/. a year. 
Happily this tax has long been abolished. In the year 1881 
the production of rock salt in Cheshire was 166,740 tons, in 
Ireland 30,891 tons. In the same year the production of 
white salt irom brine was, in Cheshire 1,600,000 tons, 
Worcestershire 226,000 tons, and Staffordshire 4,000 tons, the 
both kinds of the aggregate value of 1,149,1107. 

Referring now to the section, fig. 7, there are in the division 
4 two series of beds below the red sandstones that lie at the 
base of the section. The lowest of these is known as the Lower 
Mottled group, and it has a thickness, in Lancashire, Cheshire, 
and Shropshire, ranging from 200 to 500 feet, ihe next group 
in ascending order is that of the Pebble beds, which range 
from 500 to 750 feet in thickness. Above these beds come 
those shown in the base of the section (4), which have a thick- 
ness of about 500 feet. 

Above these beds there occurs in Germany a small series 
of beds known as ' Muschelkalk,' but so far this member of the 
Trias, as the whole series is termed, has not been recognised 
in England. The beds No. 2 and 3 of the section form to- 
gether the lower part of the Keuper, or highest division of the 
Trias. They consist first in ascending order of a series of 
flagstones and sandstones of pale buff and red colour, on the 
bedding surfaces of some of which are beautiful impressions of 
the footprints of birds and reptiles, good examples of which 
have been obtained from the Grinshill quarries of the Hawk- 
stone hills. These are succeeded by a similar succession of 
flagstones and marls, the two series having a combined thick- 



70 EARTHY AND OTHER MINERALS. 

ness of from 450 to 500 feet. Fig. 8 gives a general view of 
this division of the strata as the beds crop out in the ridges of 
the Peckforton and Delamere hills. 




FIG. 8. GENERAL VIEW OF THE PECKFORTON HILLS, CHESHIRE. 

The red marls (i), which form the highest beds of the Trias, 
attain in Lancashire the great thickness of 3,000 feet. Fortu- 
nately for the winning of the rock salt, they do not reach any- 
thing approaching this thickness in the Cheshire salt-field, as 
the following detailed section of the strata overlying the salt 
deposits near Northwich will show. 

DETAILED SECTION OF STRATA SUNK THROUGH AT WITTON, 
NEAR NORTHWICH, TO THE LOWER BED OF SALT. 

Ft. In. 

1. Calcareous marl 150 

2. Indurated red clay 4 6 

3. ,, blue clay and marl . . . . . .70 

4. Argillaceous marl ' . . I o 

5. Indurated blue clay I o 

6. Red clay, with sulphate of lime in irregular branches . 4 o 

7. Indurated red clay with grains of sulphate of lime inter- 

spersed .40 

8. Indurated brown clay with sulphate of lime crystallised 

in irregular masses and in large proportion . .120 

9. Indurated blue clay with laminae of sulphate of lime . 4 6 

10. Argillaceous marl .40 

11. Indurated brown clay laminated with sulphate of lime . 3 o 
12.. Indurated blue clay, ditto 3 



Carried forward . . 63 o 



DESCRIPTION OF THE CHESHIRE SALT BEDS. 71 

Ft. In. 
Brought forward . . 63 o 

13. Indurated red and blue clay 120 

14. Indurated brown clay with sand and sulphate of lime 

irregularly interspersed through it. The fresh water, 
at the rate of 360 gallons per minute, forced its way 
through this stratum 13 O 

15. Argillaceous marl 5 

1 6. Indurated blue clay with sand and grains of sulphate of 

lime 39 

17. Indurated brown clay as next above . . . . 15 o 

1 8. Blue clay as strata next above I 6 

19. Brown clay, ditto, ditto 7 

20. The top bed of rock salt . . . . . 75 o 

21. Layers of indurated clay with veins of rock salt running 

through them 31 6 

22. Lower bed of rock salt 115 o 

341 9 

On the north-west side of Northwich, the upper bed of salt- 
rock ranges fr3m 84 to 90 feet. It decreases eastward to 80 
feet, and to the south-west it loses 12 to 15 feet in the course 
of a mile. It would thus appear to form a large lenticular 
mass, it being probable also that in extending over a larger 
area it may again thicken. Only 12 to 15 feet near the 
base of these upper beds are considered pure enough for 
working. 

At Marston, the lower bed is 96 feet thick. In the section 
above given its thickness is 115 feet; at other mines it has 
been penetrated to a depth of 1 1 7 feet without the bottom 
being reached. 

In the upper 70 feet of the lower bed, the salt occurs in 
irregular strings and masses, associated with gypsum. It is the 
lower half that contains the most salt, but of this portion only 
from 15 to 20 feet near the base are worked. 

The rock salt varies from yellow to red and reddish brown 
in colour, its colour varying with the different proportions of 
iron it contains. It is crystalline in structure, and fine cube 
crystals of pure salt occur in places. 

The following analysis gives its general composition : 



72 EARTHY AND OTHER MINERALS. 

Chloride of sodium .... 98-32 

Sulphate of lime ..... 0-65 

Chloride of magnesium .... 0-02 

Chloride of calcium .... croi 

Insoluble matter i - co 

The rock salt sometimes appears in irregular column al 
shapes, and sometimes in rounded masses which seem to be 
compressed into each other. Both the beds of rock salt and 
those of gypsum abound in the remains of minute forms of life 
Estheria and Foraminifera. 

The upper marls, with their salt deposits, extend south-east 
to Audlem, where they are covered with a thin coating of Lias. 
Brine springs are found here, but the brine is rather weak. As 
we approach the north-west, towards Nantwich and Beeston, the 
brine becomes stronger. Eastward there are indications of salt 
to Congleton and Lawton, and northward to Frodsham. The 
great mass of the salt, however, seems to be about North wich, 
Winsford, and Marston. The lakes of Budworth and Pickmere 
seem to lie in hollows formed in the outcrops of the salt-beds. 
Still further to the south-east there are brine springs worked near 
Weston, north of Stafford. The salt-bearing marls are bounded 
by two divergent ranges of escarpments, which, starting north- 
east of Shrewsbury, range the one in the Grinshill and Hawk- 
stone hills to the north-east, and the other beginning in a few 
isolated hills, at last becomes continuous in the Peckforton and 
Delarnere hills, running to the north-west. In the year 1873, the 
date of Mr. Dickinson's report, there were at work in Cheshire^ 
Staffordshire, and Worcestershire 19 salt mines and 49 brine 
springs. Formerly the salt mines were worked by a single 
shaft of very small diameter. At present, although the 
diameter of the shafts is small, there are now usually two sunk 
to the salt-bed worked, and a third for pumping is sunk to just 
below the base of the drift and soft beds, in order to prevent 
the surface waters running into the mine. As already inti- 
mated, the workings are about 15 to 18 feet high; the roof 
being supported by thick pillars from 7 to i o yards square, and 
from 20 to 25 yards apart, according to the nature of the roof 
and the overlying strata. The salt rock between is removed 




ham 



COMPOSITION OF BRINE 

by blasting. The drills used are about 8 feet 

each end, and thick in the middle for handling, 

being used. The old fashion, too, of using a straw filled with 

fine powder for a fuze is also practised. The winding is now 

done by steam-engines in the usual way, and tram-roads are 

used underground ; no sleepers are used, the rails being fastened 

to the rock floor of the excavation. 

About 300 persons are employed at the salt mines of North- 
wich and Winsford. The day's work below ground is either 
from seven in the morning till three in the afternoon, or from 
eight to four, with two half hours out for meals. The mines 
are clean and dry. free from carbonic acid gas. There is plenty 
of head room. The workmen look healthy, and sanitary 
arrangements are well attended to. 

Besides the mines worked in the rock salt beds, there are 
the brine springs and the pumping arrangements. Indeed, we 
have seen that this is the oldest industry of the two. The 
composition of the brines of Cheshire and Worcestershire is 
given in the following analysis : 





CHESHIRE. 


WORCESTERSHIRE. 


. . r> T> 






(Constituents in 100 -Parts r$nn6 


Marston. 


Wheelock. 


Droitwich. 


Stoke. 


Chloride of sodium . 


25-222 


25-333 


22-452 


25-492 


Chloride of potassium . 












Bromide of sodium 


on 


020 


trace 


trace 


Iodide of sodium 


trace 


trace 


trace 


trace 


Chloride of magnesium 





171 








Sulphate of potash 
Sulphate of soda 


trace 
146 


trace 


trace 
390 


trace 
'594 


Sulphate of magnesia . 












Sulphate of lime . 


"391 


418 


'3^7 


261 


Carbonate of soda 


/- 
036 




115 


016 


Carbonate of magnesia 


107 


107 


'34 


'34 


Carbonate of manganese 


trace 


trace 






Carbonate of lime 


trace 


trace 


trace 


trace 


Phosphate of lime 


trace 


trace 


trace 


trace 


Phospha ' . oxide 


trace 


trace 


trace 


trace 


Alumin; 


trace 


trace 








Silica . 






trace 


trace 




25-9I3 


26-049 


23-378 


26-397 



74 EARTHY AND OTHER MINERALS. 

The rain falling upon the surface finds its way to the rock, 
entering which by cracks and softer strata it percolates through 
the beds, and taking up into solution the salt they contain, the 
water flows on until it finds a natural outlet at a lower level 
than that at which it entered, or into abandoned salt mines, or 
into wells sunk on purpose, whence it is pumped up and run 
into pans, which are subjected to heat, the water passing off in 
vapour and the salt remaining. This constant abstraction of 
the solid substances of the strata is producing serious effects in 
the district. The land sinks, boundaries are removed, roads 
are turned into rivers, and rivers and canals into roads. In 
the towns, Northwich especially, the houses are nearly all 
crooked, and are propping one another up in the spirit of true 
reciprocity. Occasionally a house altogether disappears, to the 
great jeopardy of its occupants. What the end of all this will 
be it is difficult to say. It seems useless to build houses on 
moving and unstable ground, and it is probable that the district 
immediately concerned will be given up to agriculture and the 
production of salt, the dwellings being erected around the 
outer margin of the shifting area. The usual royalty payable 
to the landowner ranges from 2d. to 6d. per ton, with a ground 
rent for land occupied. For brine the terms are very various. 
Sometimes the royalty is merged in an annual rent, at the rate 
of about 507. for a Cheshire acre equal to 10,240 square 
yards. The highest price for salt made from it is about IQS. 
per ton. 

Worcestershire. Droitwich, the centre of the Worcester- 
shire salt industry, lies about twelve miles to the north-east of 
the city of Worcester. Between the two towns, good sections 
of the waterstones and other beds underlying the upper red 
marls are exposed, as are also the strata between the salt strata 
and the waterstones. Droitwich is situated upon the red marls 
themselves, and through the incessant outflow and pumping of 
the brine, the town is in the same danger of falling in as is 
Northwich. About thirty-five years ago the ground cracked 
along the axis of the hill to the east of the town, very sud- 
denly, so that the sheep feeding close by disappeared in a 



THE SALT SPRINGS AND BED OF DROITWICH. 75 

chasm. Latterly, the houses have been built up on strong 
wooden frames. Salt springs are also worked at Stoke Prior, 
to the north-east of Droitwich, on the way to Bromsgrove. At 
Droitwich the brine springs are in the town, which lies in the 
narrow valley of the river Salwarp. The sides of the valley 
rise very steeply to a height of 60 to 80 feet. 

The prevailing rock near the surface is a clayey calcareous 
sandstone of a brownish red colour with spots and patches of 
bluish green. The brine is reached in the pits or wells at a 
depth of from 100 to 180 feet. The general succession of the 
strata in descending order seems to be soil and drift 5 to 15 
feet ; marl, the rock above described, 30 to 40 feet ; hard, 
flaky or slaty gypsum, formerly called locally, talk, 70 to 120 
feet. Immediately in passing through the bed or beds of 
gypsum the brine is reached, and from the tools dropping 
22 inches to 2 feet, it is inferred that there is a river or lake of 
brine of that depth. When struck the brine rushes up the bore- 
hole with great force, which indicates that it has its origin at a 
greater height than that it occupies in the region of the wells. 
This brine stream rests upon a salt bed. At Stoke Prior the 
pits are deeper than at Droitwich. A shaft was sunk in the 
year 1829 to a depth of 153 yards, and the rock salt was 
mined, but only for a short time. The section of the salt beds 
here was 

Yds. Ft. In. 

To top of rock salt through red marls with gypsum and salt . 121 o o 

Red mar], with veins of rock salt 026 

Rock salt, red, with from 7 to 20 per cent, of marl . 13 o o 

Flesh-coloured red marl with veins of rock salt . . . 800 
Rock salt with from 7 to 22 per cent, of marl (not passed 

through) . . . - 10 o o 

152 2 6 

The brine flowing and obtained from the pits is for the 
most part colourless ; sometimes it has a palish green hue, like 
that of sea-water. It contains from 2,000 to 2,290 grains of 
salt to the pint. It differs from the Cheshire brine in its con- 
taining about 2 per cent, of sulphate of soda. It is also freer 
from carbonate of lime, oxide of iron, and chloride of lime than 



76 EARTHY AND OTHER MINERALS. 

is the Cheshire salt. In the Government returns the salt ob- 
tained from near Weston, in Staffordshire, is combined with 
that of Worcestershire. The combined production of white 
salt from the two counties, at Shirleywich, Stoke Prior, and 
Droitwich, was in the year 1881 235,750 tons. Seventy years 
ago the annual production was 16,000 tons, of which the prin- 
cipal part was consumed in England. This production paid a 
tax of about ,320,000. The market price of salt at that time 
was ^31 a ton, of which ^30 was duty. 1 

Although not of importance commercially, it may be inter- 
esting to note that at Ashby wolds, in the Ashby de la Zouch 
coal-field, or Leicestershire coal-field, a century ago there were 
salt springs at a depth of 225 yards from the surface, which 
contained from 5 to 6 per cent, of salt. Higher up in the 
series a spring less saturated with brine flowed through the 
fissures of the coal with a hissing noise, supposed to be caused 
by the emission of hydrogen gas. Some attempts seem to 
have been made to utilise these brine springs, but they were 
abandoned, partly owing to the weakness of the brine and 
partly to the prejudicial operation of the salt-tax. 

NORTH OF ENGLAND. Formerly salt was produced on an 
extensive scale about the mouth of the Tyne by the evaporation 
of sea-water. About two hundred years ago 200 pans were 
employed for this purpose. In addition to sea-water, brine 
springs were also to some extent used. At Long Benton 
Collieiy, in Northumberland, the proprietors had early in the 
present century the exclusive privilege of extracting soda from 
salt springs in the Coal-measures without paying the usual duty. 
The principal salt works were grouped about and in some cases 
gave names to, Howdon Pans, Hartley Pans, Jarrow, and North 
and South Shields. At the latter place reminiscences of the 
trade remain in the fact that the town is still divided into East 
Pan and West Pan wards. Other evidences of the extent of 
the trade remain in the large hills formed of the ash of the 
salt-pans. 

1 'Horner Brine Springs at Droitwich.' Transactions, Geological 
Society, vol. ii., p. 99. 



DISCOVERY OF SALT IN DURHAM. 77 

The production of salt from these sources gradually gave 
place to the use of salt obtained from Cheshire and Ireland. 
Sea-water is, however, still largely used to dissolve the rock 
salt derived from those sources. From 90,000 to 100,000 tons 
of white salt are decomposed annually on the Tyne in 74,000 
to 80,000 tons of sulphuric acid, the result being from 100,000 
to nc,ooo tons of sulphate of soda. 

At the present time there is every prospect of the region 
south of the Tyne becoming a great salt-producing district. 
In the year 1864 it was announced that a bed of rock salt 
had been discovered near Middlesborough. This discovery 
resulted from a shaft and boring begun on July 4, 1859, by 
Messrs. Bolckow and Vaughan, for the purpose of securing 
a supply of water for their works. As this discovery will 
probably be of great importance to the trade of the district, it 
will not be out of place to place on record here the details of 
the strata passed through in this shaft and bore-hole. At the 
present time it is said that arrangements are being made by 
the firm named to work the salt deposit. 

Particulars of strata sunk and bored through at Middles- 
borcugh-on-Tees by Messrs. Bolckow and Vaughan. The 
sinking was commenced on July 4, 1859. 

No. Description of Strata. Thickness. 

Fms. Ft. In. 

1 Made ground . ....... I 5 o 

2 Dry slime or river mud .... I 2 o 

3 Sand containing water ... 140 

4 Hard clay (dry) . . -. . . 140 

5 Red sand with a little water . o i o 

6 Loamy sand with a little water . . o 3 o 

7 Hard clay (dry) ... . 230 

8 Rock mixed with clay and water . . 150 

9 Rock mixed with clay (dry) . o i o 

10 Rock mixed with gypsum (dry) . i o o 

1 1 Gypsum with water .... 020 

12 Red sandstone with small veins of gypsum 

and water ..... 910^ 

13 Gypsum rock (dry) .... i o o 

14 Brown shale with water ... o i o 

15 Red sandstone . . . . . .040 

Carried forward . . . 24 o o 



78 EARTHY AND OTHER MINERALS. 



No. 


^Description of Strata. 


Thickness. 






Fms. 


Ft. 


In. 




'Brought forward 


2 4 








16 


Red sandstone, with veins of gypsum and water 


2 


O 


O 


17 


Bluish rock 





3 





18 


Red sandstone with water .... 


3 


i 


O 




Bottom of shaft . 


29 


4 





Boring. 19 


Red sandstone 


72 


5 


4 


20 


Red and white sandstone .... 


o 


i 


6 


21 


Red sandstone 


35 


5 


7 


22 


Ditto, with clay 


o 




o 


23 


Red sandstone 


8 


4 


3 


24 


Ditto, and clay . . . . 


i 


3 


o 


25 


Red sandstone . . ..'.... ; 


ii 





5 


26 







2 


9 


27 


) 








28 


> Red sandstone and clay . . . , . 


6 


I 


ii 


29 


1 








3 


Red sandstone with a vein of blue rock 


8 


I 


4 




Red and blue sandstone .... 





I 


5 


3 2 


Red sandstone 


i 


o 


o 


33 


Ditto, with thin veins of gypsum . 





I 


5 


34 


Ditto, ditto 


6 


3 


8 


35 


Red sandstone, blue clay, and gypsum 





i 


2 


36 


Ditto, with veins of gypsum .... 


14 


3 


3 


37 


Gypsum ....... 





3 


2 


3* 


White stone 





o 


8 


39 


Limestone ....... 





2 


8 


4 


Blue rock 





O 


2 


4 1 


Blue clay 








2 


42 


Hard blue and red rock ..... 








10 


43 


White stone 





2 


7 


44 


Dark red rock 





I 


2 


45 


Dark red rock, rather salt .... 


I 


O 


7 


. f 46 




2 





7 


^ 47 


Ditto, very dark 





4 


i 


w tf , 48 


Ditto, very light 





3 


6 


12 -3 49 


Ditto, rather dark 


4 


3 


4 


m 3 5 
V 51 


Ditto, very light ...... 
Ditto, rather light 


7 

i 


i 
3 


6 
o 


5 2 


Limestone ....... 





i 





53 


Conglomerate, limestone, and sandstone, 










with much salt 


i 





4 



218 5 4 
Or 1,306 feet. 

It will of course depend upon the extent of these salt 
deposits whether they can be profitably worked, but the thick- 
ness is so great that the probability is the beds extend over 



SALT DEPOSITS OF IRELAND. 79 

a large area. Then while some of the beds, as in Cheshire, 
may not be pure enough for profitable working, there will be 
thicknesses that may be advantageously mined as in Cheshire 
and at Wieliezka, as described in the next chapter. An 
analysis of a sample of the rock salt gave the following 
results : 

Chloride of sodium .... 96-63 per cent. 

Sulphate of lime .... 3-09 

Sulphate of magnesia . . . O'o8 

Sulphate of soda . . . . o-io 

Silica 0-06 

Oxide of iron trace 

Moisture 0-04 

100-00 

The sample was probably one of the lighter varieties. 

Following the success attending Messrs. Bolckow and 
Vaughan's exploration, Messrs. Bell Brothers have had a small 
shaft, 16 inches diameter, put down by the Diamond Rock 
Boring Company near to the works at Fort Clarence. This 
shaft or borehole is 1,200 feet in depth, and it has pierced beds 
of rock salt 80 feet in thickness, which thus proves the con- 
tinuity of the salt deposits over some extent of area. It is 
intended to let fresh water down this shaft and to pump it up 
as brine. 

IRELAND. Rock salt and salt made from brine have been 
produced near Carrickfergus for near a century past. The 
production of rock salt in the year 1881 was 31,730 tons, and 
of white salt, estimated, 64,000 tons. About a century ago a 
trial pit was sunk near an old hole on the west side of the 
Eden, near Carrickfergus, which from time immemorial had 
been known as the salt hole, but the result was not satisfactory 
and the shaft was filled up. Subsequently it was noticed that 
brine oozed out through the filling. A trial was then made by 
Mr. M. R. Dalway, who discovered a little brine in or near a 
hard bed in the sandstone about eight yards from the surface. 
Mr. Dalway then sunk a pit to the east, on the dip of the 



80 EARTHY AND OTHER MINERALS. 

strata. This shaft was taken down about 177 yards. It 
reached the hard bed just referred to and a little brine was 
obtained, but not enough for profitable working. Mr. Dalway 
also sunk another shaft to a depth of about 233 yards, with a 
boring below for 17 yards, all in marl, without finding brine. 
This was about a quarter of a mile from the present salt-pits 
at Dunerne. In the year 1851 rock salt was discovered at 
Dunerne to the east of Mr. Dalway's explorations. As at Mar- 
bury Lane in Cheshire, so here the discovery was made in a 
trial shaft on the Marquis of Downshire's estate, being sunk in 
the hope of finding coal. Following this discovery other 
shafts were sunk, and the rock salt has been worked ever 
since. 

The following is a general section of the strata at Dun- 
erne : 

Yds. Ft. In. 
Soil . .... o i 6 

Brown drift with boulders of chalk, limestone, flint, &c. . 20 I 6 
Brown, and a little blue marl, with gypsum . . . 224 o o 

245 o o 

Rock salt 500 

Brown marl and mailstone . 200 

Rock salt 3100 

Brown marl and marlstone ....... o I o 

Rock salt 15 o o 

Total depth from surface .... 298 i o 

This is Mr. Dalway's mine, whose spirited trials were at 
last rewarded with success, and it is the deepest salt-mine in 
the British Islands. In this mine about 40 feet thickness of 
rock salt is worked. Pillars 14 yards by 12 at the bottom 
and 12 yards by 10 at the top, are left standing at intervals of 
25 yards square apart. At the Belfast Mining Company's mine, 
in the same neighbourhood, 10 yards of rock salt are worked, 
and the pillars are 16 yards by 12 at the bottom, and 12 yards 
by 8 at the top, and the same distance apart. It has been 
found from experience that with pillars of less strength or 
frequency the workings crush in. 



8i 



CHAPTER V. 
CHLORIDE OF SODIUM continued. 

Salt Deposits of France, of Switzerland, of Spain The Salt Mines of 
Cardona, on the Ebro, near Burgos The Sea Salt Gardens of the 
South-west Coast Analyses of Sea Water Salt Deposits of Italy, of 
Germany, Mecklenburg- Schwerin, Hanover, Anhalt, Wiirtemburg, 
Bavaria Salt Deposits of Austria, Salzburg, Wieliezka Description 
of the latter Mine The Sea Salt Gardens of Istria and Dalmatia Salt 
Mines of Roumania, of Russia, Solikamsk, Tchapatchi, Orenburg 
Salt Lake in the Crimea Salt Deposits of Africa, of Asia, Caspian 
Sea, Palestine Chemical Composition of the Water of the Dead Sea 
The Salt Deposits of Persia, of India Bahadur Khel Table of 
Strata Kohat Salt Range North America " Licks " of Michigan 
Petit Anse Island, Louisiana Nevada Salt Lake of Dr. Chas. 
Darwin's Description of a Saline in Patagonia Inferences and Con- 
clusions. 

IN FRANCE, brine springs occur in several places at Salies, 
south of Toulouse, at Salenars and Montmorat, in the Jura, 
and near St. Maurice. At Arbonne, in Savoy, at an elevation 
of 7,200 feet above the sea, in the region of perpetual snow, 
are masses of saccharoid gypsum which are imbued with chlo- 
ride of sodium, and which become light and porous when the 
salt has been removed by water. In SWITZERLAND, extensive 
beds of rock salt associated with gypsum occur in the upper 
marls of the Trias, or at the base of the Lias, near Bex. 

SPAIN. In this country there are extensive salt deposits, 
and salt is manufactured from sea-water to a considerable extent. 
Of the former perhaps the most important is that of Cardona, 
in the province of Catalonia, in the north-east of Spain. 

The district consists of an elevated plain or plateau, through 

G 



82 EARTHY AND OTHER MINERALS. 

which a valley is excavated, along which runs the river Car- 
dona. Along the sides of this valley, and especially near the 
town of Cardona, are cliffs of red salt, the town of Cardona 
itself standing on what has been termed a mountain of salt. 
The soil of the district is about six inches thick, and it is 
impregnated with salt, on which vineyards flourish luxuriantly. 
The workings in the rock salt are in the hill on which the town 
stands, and in the cliffs in the immediate neighbourhood, for 
about a mile and a half up and down the valley. The place 
where the industry centres is an oval valley about a mile and a 
half long by half a mile wide, extending from the castle of Car- 
dona to a promontory of red salt at the other end of the oval. 
The salt rock in this promontory is 663 feet high and 120 feet 
wide at its base. The 120 feet represents the thickness of the 
bed, the beds being probably highly tilted, and the 663 feet a 
portion of its extent. So far the workings do not appear to 
have descended below the bottom of the valley. A rivulet finds 
its way underground throughout the salt rock, and issues out 
so strongly charged with salt that in time of floods, when it 
enters the river Cardona, it kills the fish. 

The colour of rocks of the district, as well as of the salt, is 
red, and the strata abound with crevices and chasms in which 
cluster stalactites of salt like bunches of grapes. As the sun 
rises over this scene the effect is described as very beautiful, 
the mountain of Cardona sparkling as with thousands of 
precious gems. 

As elsewhere, accurate examination shows that the salt 
deposits occur as large irregular masses in marls and sandstones 
which themselves are more or less impregnated with salt. 

An extensive deposit also occurs between Caparosa and 
the Ebro ; a bed of rock salt 5 feet thick interstratified be- 
tween gypsum and limestone at Valhirra. Another deposit, at 
Posa, near Burgos, is said to present indications of volcanic 
origin, being associated with pumice-stone, and occurring in or 
near the supposed crater of an ancient volcano. 

Notwithstanding these extensive natural salt deposits, the 
roads and other means of communication have been so defec- 



COMPOSITION OF SEA WATER. 83 

tive in Spain that the inhabitants of a considerable tract along 
the south-west coast cultivate what may be called salt gardens. 
The sea with each tide is let into a series of ponds, which are 
constructed for the purpose, in a clayey soil, to a depth of from 
2 feet to 6 feet. In the first pond a subsidence of mud takes 
place; the water is then conducted by a long channel to a 
second pond, where a further subsidence of mud occurs. Then 
by a series of channels the water is led through a series of 
shallow pits, like the settling-pits at a lead mine, only not so 
deep, in which the salt crystallises, and from which the clear 
water flows off to the sea. 

With this reference to the production of salt from sea-water 
it will be interesting to notice the result of three analyses 
of the same, which were as follows to 1,000 parts : 





i. 


2. 


3- 


Chloride of sodium 


24-84 


26-66 


25-00 


,, magnesium . . . 


2-47 


5-15 


3-50 


,, potassium 
Sulphate of lime 
,, magnesia ; 


1-20 
2-06 


1-23 
1-50 


O'lO 

0-58 


,, soda 





4-66 





Carbonate of lime and magnesia 








0-20 




31-87 


39-20 


29'33 



In addition to the foregoing there were 6*2 per cent, of 
carbonic acid, with traces of manganese, iron, phosphate of 
lime, silica, the bromides and iodides of the metals, some 
organic matter, and ammonia. 

In ITALY the volcanic mountain of Cologero, near Sciacca, 
in Sicily, contains a considerable amount of rock salt imbedded 
in its layers. 

GERMANY. Very extensive salt deposits occur in the North 
of Germany, extending from near Hamburg on the west, through 
the Grand Duchy of Mecklenburg-Schwerin towards Stettin on 
the east, and extending to Hanover and to Magdeburg and 
Stassfurth on the south. The mines at the latter place are 



84 EARTHY AND OTHER MINERALS. 

said to yield a royalty of 400,000 thalers yearly to the Prussian 
Government, and to the government of Anhalt 250,000 thalers. 
The most active operations hitherto have been in the southern 
half of the area described, but important explorations and dis- 
coveries have during recent years been made along the northern 
portion of the area. Near Jessemtz, about 65 miles from 
Hamburg, a boring put down by order of the Mecklenburg 
Government proved saline and gypsiferous strata, containing 
also potash and other salts, to a thickness of nearly 200 feet. 
Another boring put down at Liibtheen, near Hagenow, to a 
depth of 1,496 feet, had at the bottom a thickness of salt of 
426 feet. Southwards, at Minden, in Prussia, near Hanover, 
a boring was started in the Lias, and having passed through 
the Upper Keuper marls reached the Muschelkalk at a depth 
of 2,515 feet. From this depth, which, as we have seen, lies at 
or rather below the ordinary base of the salt deposit, 84 cubic 
feet of liquid, containing 4 per cent, of chloride of sodium, 
issued from the boring per minute. 

In Wiirtemburg, in the south of Germany, salt deposits com- 
mence at Hall, and are continued south-east through Bavaria 
to Halstadt, Ischel, and Ebensel in Austria. In Wiirtemburg 
these deposits have been long worked near Wimpfen. 

A large proportion of salt produced in Germany is obtained 
from brine springs, and from brine wells-by means of pumping. 

In some of these, as at Wimpfen, the natural flow or yield 
of the brine is supplemented by artificial means. A hole is let 
down to the salt-bed, in which a pump is fixed, but space is 
left around the pump down which fresh water is sent. This 
becomes impregnated with salt, and is pumped up brine. The 
brine derived from this source contains an average of 27*00 
of chloride of sodium. 

Besides chloride of sodium, which in the natural springs 
ranges from 0-155 to 9-623, there are in the liquids varying 
small proportions of other minerals, including the chlorides of 
potassium, magnesium, and calcium, the carbonates of lime, 
magnesia, soda, and manganese, and the sulphates of potash, 
lime, soda, and magnesia. The artificial wells which have 



SALT DEPOSITS OF AUSTRIA. 85 

been sunk to the salt beds are usually stronger in chloride of 
sodium than are the waters of the natural springs. Many of 
the latter are too dilute for profitable evaporation by artificial 
means. At Salzhausen it takes the evaporation of 339 cubic 
feet of brine to produce i cwt. of salt, and at Schonebeck 
19,000,000 cubic feet of brine are required to produce the 
annual yield of 28,000 tons of salt. In the case of weak brines 
therefore the greater proportion of the liquid is first removed 
by gradual evaporation in the open air, so as to bring the solu- 
tion up to a sufficient strength for profitable working by 
artificial evaporation. 

AUSTRIA. Salt is produced in the Austrian Empire both 
by mining and by the evaporation of sea-water. Both indus- 
tries are monopolized by the Government, and the profits are 
credited to the revenue. The average production of salt in 
the empire may be taken as rock salt 554,000 centners, refined 
salt 1,500,000, sea-salt 220,000, and salt for manufacturing 
purposes 14,000. 

Of the mines the principal ones are those of the Salzberg 
in the south-west, and of Wieliezka, near Cracow, in the north 
of the empire. 

The deposits of the Salzberg seem to be a continuation of 
or closely related to those of Wiirtemburg, in Germany. One 
of the most ancient and extensive of the mines is situated 
about 8 miles north of the town of Hall, in the Austrian Tyrol, 
and on the left bank of the river Inn, below Innsbruck. It 
lies on red sandstone, marls, and rocks, and at an elevation of 
6,300 feet above the sea. There are records extant which 
show that there were salt-works in operation here early in the 
eighth century. In all probability these depended upon a salt 
spring which rises at the foot of the mountain. In the year 
1275,50 the story goes, Niktes von Rohrbach, der f rammer 
Ritter, or pious knight, frequently noticed on his hunting 
expeditions that the cattle loved to lick certain cliffs of the 
valley. This led him to taste the flavour of the rock for himself, 
and finding it rich in salt, he followed up the track until he 
came to the Salzberg itself, where he inferred from his observa- 



86 EARTHY AND OTHER MINERALS. 

tions there was an immense supply of salt. Since that time 
the salt has been worked, first by hewing and later by blasting. 
Vast chambers, some of which are an acre in extent, have been 
excavated in the rock, which have been subsequently closed 
up and filled with water. At the end of a year or so the water 
becomes impregnated to about one-third its weight with salt, 
and it is led off by means of conduits to Hall, where it is 
evaporated. The process of excavation is repeated when 
necessary. 

These salt-beds are continued on to Styria on the north- 
east, where they are also to some extent worked. 

The other great salt mine of Austria is the famous one of 
Wieliezka, near Cracow, in Galicia. This mine has been worked 
since the year 1251, and it has still vast reserves of the mineral. 
Fig. 9 shows a general section of the strata of this mine, and 
the similarity of the rocks to those in which the great salt 
deposits of England lie will be at once recognised. The salt 
occurs in large lenticular and irregular shaped masses, in a red 
marl rock. These masses are for the most part very pure. In 
the rock itself there are numerous impressions of vegetable 
remains, especially in the upper portion overlying the salt 
deposits. The fig. 9 shows how the deposits are worked, 
first by a shaft sunk down to the top of the deposits, and then 
by a series of slanting tunnels which cut through the salt 
masses. At these points of intersection the latter are excavated, 
leaving vast chambers, from whose roofs stalactites hang and 
glisten when the mine is lighted up, and in the sunken floor of 
the chambers, where the salt mass has been followed down, 
there are lakes across which the exploring traveller is ferried in 
boats. 

The daily wages of the workmen employed in this mine is 
about 2s., varying somewhat according to the skill and posi- 
tion of the workman. There are also, in addition, grants of 
firewood and salt. The mine has been worked to a depth of 
over 400 yards. An American traveller gives the following 
popular account of a visit he made to this mine some years 
ago. 



WIELIEZKA SALT MINE. 



* A long winding stair of several hundred steps, neatly 
covered with boards, led to the first story. Long alleys con- 
ducted to the chambers.;, which, in the course of six centuries, 




Vegetable soil. 
Sandy clay. 

Fine sand, 
like Tripoli. 

Marl 

with 

sand and * 
sandstones. 
^JJS Sandstone. 

J~ __ ~^J-- Marl mixed 

:"_- ~~ = ^ = I-r_ with sand 

'_-~ "I. 3}-^ in particles 

I" H-j- -T" __~~^~ and small . 

~-r"-~^^~~~ r ~ ^~i cubes. 




Salt deposits 
in beds and 
irregular masses 
in marl mixed 



FIG. 9.-SECTION OF STRATA AT THE WIELIEZKA SALT MINES, AUSTRIAN POLAND. 
Scale i" = 150 Feet. 

have been excavated in the solid salt. These chambers are 
well proportioned, and present an appearance of cleanliness 
and neatness which at once reconciles the visitor. No 
humidity, no closeness, no chilling draughts, but a dry, airy, 
never varying temperature pervades these subterranean caverns. 



88 EARTHY AND OTHER MINERALS. 

The halls up on the first floor have been named after the 
various monarchs of Poland and Austria, and are decorated 
with their statues or the monuments erected to their memory. 
Another chamber is called the chapel of St. Cunegunda, and on 
the day of her festival high mass is celebrated in the presence of 
the miners. The largest of the chambers was the concert hall or 
the theatre. There were the orchestra, saloons, galleries, and 
from the arched roof above hung a chandelier of salt. Some 
of the guides ascended to the uppermost tier, and waving their 
blazing brooms illumined the gloom above and around them. 
The light falling upon the crystal walls, and the grim shadows 
trembling and struggling upon the brink of the darkness which 
reached far beyond into the deep gulf, was marvellously beauti- 
ful. Again descending we reached the second story, and 
threading the long passages arrived at the borders of a lake 
where a boat and torchbearers awaited us. 

'We landed upon the opposite side of the lake, and 
descended to a chamber immediately beneath ; but we were 
already 600 feet below the surface and thought this quite 
sufficient. The whole mass above was supported by arches 
and pillars of salt, as solid and hard as adamant. Some of the 
latter have been cut away and immense beams of wood sub- 
stituted in their place. There are no clefts or gaps in the 
length or breadth of this spacious vault. All is solid and 
secure, and the idea of accident or damage never occurs to the 
observer. The rock in its general appearance, and in a doubt- 
ful light, resembles our gray granite, except that it has more 
brilliancy that kind of brilliancy imparted to the texture of 
ordinary quarries containing crystallised quartz. Where the 
water has filtered, crystallisations appear in the forms of cubes 
and prisms, and where these are seen with the aid of a number 
of torches, the effect is very beautiful.' 

In Istria and Dalmatia, along the east coast of the gulf of 
Venice and the Adriatic Sea, are important saltworks at which 
the salt is evaporated from sea -water in much the same 
manner as that practised on the south-west coast of Spain. 
In this industry 4,400 persons are employed, including 1,700 



SALT DEPOSITS OF RUSSIA. 89 

women and 1,450 children, and the production of salt from this 
source averages, as we have seen, 220,000 tons a year. 

Passing eastwards, into the newly formed kingdom of 
ROUMANIA, we find five salt mines at work, two of which are 
penal and are worked by convicts. One of these, Telega, 
half-way between Ploresti and Sinaia, is descended by a series 
of staircases to a depth of about no feet, the depth it has now 
reached. 

RUSSIA. This empire produces about 400,000 tons of salt 
annually. The Government levy a tax of 2s. 8d. per cwt. 
upon the article, which amounts to about 12,000,000 roubles 
a year. This tax is about to be reduced, if the reduction has 
not already taken place, to is. %d. per cwt. The principal salt 
works of Russia are at Solikamsk, on the east side of the 
Ural Mountains, just on the borders of Russia in Europe, and 
on the same parallel of latitude as St. Petersburg. Solikamsk 
is in the kingdom of Perm, which has given its name to our 
Permian strata; these strata, with the overlying New Red Sand- 
stone and marls, being largely developed there. The produc- 
tion of refined salt at Solikamsk is about 70,000,000 Ibs. 
annually, valued at one halfpenny per pound. The brine is 
pumped by steam-engines from a depth of from 100 to 150 
feet. It is boiled for six hours and left to settle for another 
fourteen, after which the salt is removed in wooden trays, on 
which it is left to dry. 

Of the 148 salt-works in Russia deriving salt in a similar 
manner from brine springs, about half are in the Government 
of Perm. Some of these now in active work have existed since 
the fifteenth century. 

An inferior salt, worth only is. &/. to 2s. per cwt., is 
obtained in a similar manner in the Government of Archangel. 

In the Yenotayef district of the Government of Astrachan 
is the hill Tchapatchi, which is described as being a mountain 
of rock salt, and from this source a large supply of superior 
salt is obtained. There are other similar hills more or less 
made up of salt rock masses in the same district, as well as 
numerous lakes in which salt is precipitated. Rock salt beds 



90 EARTHY AND OTHER MINERALS. 

also crop out and are worked near Fletskaya, Fattchita on the 
borders of the Kirghese Steppes east of Orenburg ; and in 
Siberia there are four imperial salt works, which are worked by 
convicts. On the northern side of the range of the Caucasus 
there are salt springs ; indeed these abound in south-eastern 
Russia. The water of a lake near Sympheropol, in the Crimea, 
is found to contain chloride of sodium 16-12, sulphate of soda 
2*444, chloride of magnesium 7*55, chloride of calcium 0*276, 
and sulphate of potash 0-7453. 

AFRICA. Before passing into Asia we may just notice that 
salt occurs largely throughout the continent of Africa. In 
Tripoli there are extensive lagoons near Bengazi which yield 
about 200,000 tons of fine salt yearly. The salt rock of 
Tegara, and those of Had Delfa, in Tunis, are also worked. 
The mineral occurs in the mountains west of Cairo, and bound- 
ing the north of Libya it extends to a great distance. It is 
also found in solid masses south of Abyssinia. Salt lakes 
occur to the east of the Cape of Good Hope, which contain 
at their bottom thick beds of rock salt variously coloured with 
extraneous matters. Along the coast in the same neighbour- 
hood salt is obtained from sea-water in the way already 
described. 

ASIA. Reference has already been made to the salt mines 
of Siberia. In portions of the same country on the coast sea- 
water is subjected to the action of frost, which separates the 
clear water into ice, leaving a residuum of strongly saline 
liquid. Salt lakes occur on the borders of the Caspian Sea, 
which are interesting from their resemblance to others in 
South America, and as throwing light upon some conditions 
under which our great Triassic salt deposits were formed. 
These lakes occupy shallow depressions in the land. The 
mud on their borders is everywhere black and foetid. Beneath 
the crust of sea-salt sulphate of magnesia occurs imperfectly 
crystallised ; the muddy sand is mixed with small strings and 
masses of gypsum. These lakes are also inhabited by small 
crustaceans. 

In PALESTINE red rocks containing saline, gypsiferous, and 



SALT DEPOSITS OF PERSIA. 91 

bituminous matter underlie the Jurassic limestones and strata 
that cover a large portion of the country and continue south- 
wards into Arabia. Hence it is that the streams running into 
the river Jordan from the Sea of Tiberias southwards come 
charged with these various substances, and all flowing into the 
Dead Sea, which is also bounded by rocks of a similar 
nature, contribute to the peculiar chemical composition of the 
waters of that lake. The water of the Dead Sea contains 
6-578 of chloride of sodium and 10*543 of chloride of 
magnesium. 

Passing to the south-east we find a considerable salt 
mining industry carried on in the hills bounding the Persian 
shore of the Persian Gulf, near its entrance into the Indian 
Ocean. The salt rocks crop out on the sides of the hills. They 
occur in layers about 4 feet thick, with intervening strata of 
earthy matter. The general appearance of the rocks is of a 
reddish colour, and they vary from marl to hard sandstone. 
There is a good deal of ochre associated with the salt deposits, 
generally lying above them ; so much so that its presence is 
taken as an indication that salt will be found below. 

The chief places of the industry are Kishm Island, Hormuz, 
Larak, Pohal, Jabel, Bostana, and Hameran. The salt usually 
occurs in reddish hard granular masses, occasionally in pure 
white masses. In secondary forms it occurs in stalactitic 
and saccharoid masses, and in translucent and transparent 
masses of a cubical form. The red salt is used by the natives 
for salting fish in connection with the extensive fishery that 
is carried on along the coast. The finer qualities are sent in 
native boats to Muscat, whence the salt is exported to 
Mauritius, Zanzibar, Batavia, and Bengal. The salt rock is 
quarried by means of powder, and it is afterwards broken by 
means of wooden and iron mallets. The result of the excava- 
tions is the formation of large caverns. At the western end of 
the district is a beautiful natural cavern formed by the dissolv- 
ing of the salt out of the rock by the passage of a stream 
through an original crack or crevice. In the salt springs, which 
are numerous, sulphurous gases abound, and also crystals of 



EARTHY AND OTHER MINERALS. 



pure sulphur. In some warm springs near the village of 
Salakh, the water, besides 'being charged with salt, yields 
naphtha of a reddish colour, which 
is highly combustible and burns 
with a thick smoke, the natives 
using it for light. The cost of 
mining the salt is given at ^s. 2d. 
per 3,600 Ibs., and the price of it at 
the sea-side at iSs. to 22s. for the 
same amount. The whole group of 
the strata enclosing the salt are 
considered to be of middle if not 
more recent Tertiary age. 

INDIA. On the west-north-west 
side of the Punjab, on both sides of 
the river Indus south of Peshawar, 
are very important and interesting 
salt deposits, the more so since they 
are so near the salt range on the east 
side of the Indus, which appears to 
be of Silurian if not an older age, 
and that on the west side of Triassic 
or Tertiary age. Of the two, that 
west of the Indus is of the greatest 
commercial importance. 1 It com- 
prises an area of 1,000 square miles 
of country, stretching from outside 
the British boundary in Afghanistan 
to near the river Indus, and lying 
between Bannu and Kohat, but 
nearer the former place. There are 
four long and sharp and narrow 

ranges of hills stretching nearly due east and west ; these are 
steep and rocky. The whole country presents a wild, barren 

1 See Memoirs of the Geological Survey of India, vol. xi. The Trans- 
Indus Salt Region,' by A. B. Wynne. With an Appendix on the 'Kohat 
Mines or Quarries,' by H. Warth. 




SALT DEPOSITS OF INDIA. 93 

appearance, with greenish-coloured soil and rocks, varied by 
bright purple colours and blood-red zones of clay, the white of 
the adjacent gypsum bands broken by pale orange-coloured or 
yellowish debris. 

The general descending order of the rocks of this region is 
given by Mr. Wynne as follows : 

SUPERFICIAL ) Diluvium, sandy river deposits, sand, recent con- 
DEPUSITS . ) glomerate, and detritus. Thickness irregular. 

( P T P . E Jl, CA^" I. Soft gray sandstone and clay conglomerated, and 

TIARY SAND- j- bould j or bble beds 50O to lg feet> 
PLEIOCENE' STONES . . ) 

1 MIDDLE TER- \ Gray and greenish sandstones, and drab or reddish 
TIARY SAND- > sandstones, with bones and fossil timber ; 2,000 to 
V. STONES . . ) 3,000 feet. 

,-Harder gray and purple sandstones, bright red and 
purple clays, slightly calcareous and conglomeritic 
LOWER TER- I bands. Bone beds occur below, also obscure plant 
MIOCENE . \ PIARYSAND- < fragments, apparently exogenous fossil timber, and 
STONES . . I in places near the base a thin layer of strongly 
ribbed bivalve shells in a bad state of preservation ; 
v I 3,000 to 3,500 feet. 

f Nummulitic limestone, Alveolina beds, more shaly 
UPPER NUM-/' limestone with a cherty band containing Gastero- 
MULITIC . .) pod sections, with several bivalves, &c. ; 60 to 100 

feet. 

Trrn-trxTTT ) \> -^ ~, ._( Red clay, lavender-coloured at top, with a*w/*'/ 
EOCENE . / RED CLAY J }n ^^u^. O ne or two sandstone bands near 
' '( the top contain fossil bone fragments; 150 10400 feet. 
T XT ( Sandstone with nummulites, or thick greenish clays 

Roir IT r and limestone bands locally developed below or at 

' ' the place of the red clay zone ; 100 to 350 feet or more. 

(White, gray, and black gypsum, with bands of dark 
gray clay, or black alum shale gypsum, sometimes 
impregnated with petroleum or bitumen, alum shale 
generally so ; series 50 to 300 feet. 

( Rock salt associated with beds of clay and sometimes 
ROCK SALT . < earthy impurities, the upper part bituminous and 
I ( base unseen ; 300 to 700 or 1,200 feet. 

Although the rock salt is in this section grouped with 
Eocene strata, some diversity of opinion seems to exist as to its 
exact age. Supposing the intervening strata to be absent, it 
might still be of Triassic age. Still, although the strata of the 
district are much contorted, there does not appear to be any 
unconformity between the undoubted Eocene rocks above and 
the gypsiferous and saliferous strata below. Fig. 10 illustrates 
the succession and contortion of the strata. 

Owing to this contorted and dislocated condition of the 
strata, the salt rocks are thrown up to the surface, in some 
places forming hills and cliffs 200 feet high. The most notable 
example of this is in the vicinity of Bahadur Khel, where it 



94 EARTHY AND OTHER MINERALS. 

forms, for the length of a quarter of a mile, high detached cliffs 
on each side of a small stream valley, forming perhaps the 
largest exposure of rock salt in the world. Fig. n, adapted 
from a beautiful lithograph accompanying the memoir re- 
ferred to, will give an idea of the appearance of these hills of 
salt. 

In this neighbourhood the salt is very pure. It is of a 
whitish or gray colour, its texture varying from a highly crys- 
talline mass, the most prevalent form, to a somewhat earthy 
salt intermingled with blue or grayish finely divided clay. 
Rarely, minute fragments of gypsum project from the weathered 
surface of the rock. 

The earthy impurities are most common in the western 
part of the district, where the largest exposures of salt occur, 
but even here only a few subordinate bands are unfit for work- 
ing. There is an absence from the salt of potassa and other 
salts which elsewhere are frequently associated with the salt 
deposits. The deposits differ from those of Persia already 
described in that the latter overlie the nummulitic formation, 
and from those of the salt range 60 to 100 miles to the east of 
the Indus in that it forms one solid mass from top to bottom, 
with few exceptions, and also in its colour, nothing like the 
red or pink salt of the Salt Range being observable in the 
Kohat district. There is also a difference in age, Silurian 
rock overlying the salt deposits of the Salt Range. 

An analysis of clean salt from the mass at Bahadur Khel 
gave the following results : 

Chlorine 59'5 2 

Sulphuric acid 1-5 

Lime 1*06 

Sodium 37 '47 

Insoluble -45 



100-00 



The salt rock is obtained by quarrying with the ordi- 
nary tools and blasting-powders. The ordinary method is as 
follows. The top soil or debris is removed from a small 



SALT MOUNTAIN OF BAHADUR KHEL. 



95 




96 EARTHY AND OTHER MINERALS. 

central portion of the area intended to be worked, then the 
salt rock is attacked and removed, the excavation widening 
downwards as wide and deep as it may safely be taken. Then 
a fresh ring-like space is cleared around the central opening, 
the latter being filled with the debris removed, and the rock 
is again removed ; the operation being repeated, the ring-like 
circumference of quarry extending with each operation, and 
the central boss or cone of debris increasing correspondingly. 
The deposits belong to the British Government, who charge a 
tax or royalty upon the salt removed. 

In the Salt Range east of the Indus the salt rock is obtained 
by ordinary underground mining. Salt deposits in springs of 
lesser magnitude and importance extend north-eastwards into 
Thibet 

AMERICA, NORTH. A chain of mountains extends along 
the west bank of the river Missouri for a length of 80 miles, 
by 45 in breadth, and of considerable height. These moun- 
tains consist largely of rock salt. The same formation extends 
into Kentucky, where the deposits are called " licks," because 
of the licking of the rocks and soil by the herds of wild cattle 
that once roamed there. In Michigan, in the year 1882, Mr. 
Crocket McElvoy, of Marine City, sank a well in the neigh- 
bourhood to a depth of 1,633 feet, when a deposit of rock salt 
was entered and penetrated to a depth of 1,633 f eet without 
the tools passing through it. The deposit seems to increase 
in thickness, but it is reached at an increasing depth as it trends 
in a south-westerly direction by Inverhuron, Kincardine, and 
Warwick. The brine is described as pure and strong. An 
extraordinary superficial deposit of rock salt is described as 
occurring in Petit Anse Island, parish of Calcacren, Louisiana. 
The island is about two miles in diameter, and the salt deposit 
on it is known to extend under 165 acres. It is covered with 
1 6 feet of soil. It has been proved to a depth of 80 feet. 
The salt occurs in solid masses of pure crystals, and it is taken 
out by blasting. The saltness of Salt River, in Arizona, is due 
to a considerable stream that, above the junction of the river 
with the Gila, flows into it from the side of a large mountain. 



SALT DEPOSITS OF AMERICA. 97 

The bulk of the manufactured salt of North America is 
obtained from brine springs. Valuable and productive springs 
are worked in the Syracuse and Salina districts and in Ohio. 
Some of these arise from a red sandstone whose geological 
place is said to be below the Coal-measures. There are also 
the salt lakes of North America, the Great Salt Lake, which 
has an area of 2,000 square miles and is situated at an eleva- 
tion of 4,200 feet above the sea. The waters of this lake are 
described as being a solution of almost pure chloride of 
sodium. 

Rock salt has been recently discovered in Nevada. There 
are the outcrops of nine beds or ledges, the thicknesses of 
which range from 30 to 300 feet. The southern termination 
of these deposits is about 7 miles from the uppermost limit to 
the navigation of the Colorado River. Some of the specimens 
are sufficiently pure and transparent as to admit of small print 
being read through them. In the same State there is an inter- 
esting salt lake, the water of which contains about two pounds 
of salt and soda to every gallon. It is several hundred feet 
deep. Soda and salt have been obtained from this lake for 
several years by natural evaporation. The water is pumped 
into tanks at the beginning of the summer season. It is left 
in these tanks during the warm summer months, until the frost 
sets in. When the first frost comes the soda is precipitated in 
crystals. The water is then drained off into a large pond, 
where slow evaporation goes on, and a deposit of common salt 
is obtained. Some beautiful specimens of Gay-Lussite. a com- 
pound of the carbonates of lime and soda, and named after the 
distinguished French chemist Gay-Lussac, are obtained from 
this lake ; the only other locality where they are found being 
the Lake Maracaibo, in South America. Both in the West 
Indies and in South America salt deposits and lakes occur. 
In St. Domingo, about 15 miles from the harbour of Barabona, 
and between that harbour and the great salt lake of Emiquilla, 
an important salt deposit occurs. The saline character of the 
country between the Andes and the Pacific is well known, 
and important salines occur in Brazil. Perhaps the following 

H 



9 8 EARTHY AND OTHER MINERALS. 

description given by the late Dr. Charles Darwin, when he 
was a young man, and attached to the ship Beagle as a 
naturalist, of the large salt lake or salina 15 miles from the 
town of El Carmen, in Patagonia, on the south-east coast of 
South America, latitude 41, will form a fitting conclusion to 
the foregoing description of the salt deposits of the world. 

' During the winter it consists of a shallow lake of brine, 
which in summer is converted into a field of snow-white salt. 
The layer near the margin is from 4 to 5 inches thick, but 
towards the centre its thickness increases. The lake is 2^ 
miles long and i broad. Others occur in the neighbourhood 
many times larger and with a floor of salt 2 or 3 feet in thick- 
ness, even when under water during winter. A large quantity 
of salt is annually drawn from the salina, and great piles some 
hundred tons in weight were lying ready for exportation. It 
is singular that the salt, although so well crystallised, does not 
answer so well for preserving meat as sea-salt from the Cape de 
Verde Islands. The season for working the salina forms the 
harvest, as on it the prosperity of the place depends. Nearly 
the whole population encamp on the banks of the river, and 
the people are employed in drawing out the salt in bullock 
waggons. The border of the lake is formed of mud, and in 
this are numerous large crystals of gypsum 3 inches long, while 
on the surface crystals of magnesia lie about. Worms crawl 
among the crystals, and flamingoes prey upon them.' The 
lakes lie in depressions in the grand calcero-argillaceous for- 
mation which extends over the Pampas from latitude 20 to 50 
south, or in the driftal deposits which lie upon it.- 

From the foregoing particulars it will be seen that salt 
deposits occur in strata of all ages, from the Silurian (salt 
occurring also in older rocks still in a disseminated form) to 
those now forming. It will also be seen how the conditions 
under which it has been deposited and also its associated mine- 
rals other combinations of soda, gypsum, magnesia, with oxide 
of iron as a colouring matter have been the same through all 
time. The artificial salt lakes of warm climates and the phe- 
nomena of salt lakes in the steppes of south-east Europe and 



GENERAL CONCLUSIONS. 99 

north-west Asia, and in North and South America, indicate to 
us the ways in which the older salt deposits were accumulated 
the thinner seams in shallow lakes, and the thick deposits in deep 
inland seas and lakes like those of the Caspian and Dead Seas 
and the deep salt lakes of America. We also see in the 
description given by Dr. Darwin of the separation of the 
different minerals in the lakes of Patagonia how the mud 
settles around the shores, how the disseminated sulphate of 
lime and sulphate of magnesia gather themselves together in 
separate masses and crystals, and how in the deeper and 
stiller portions of the water the chloride of sodium is deposited 
in a mass with but comparatively little admixture of foreign 
substances. The same operations go on in arms of the Cas- 
pian Sea and in the lakes adjacent. The results of these 
operations are very similar to the conditions observed in every 
salt-mine, masses, strings, and crystals of gypsum, other salts 
of soda and of potash lying usually, as in Germany, upon the 
salt deposits themselves, and these deposits gathered together 
in great egg, onion, and thick lense-like masses in the midst 
of the surrounding strata. Whatever other causes, therefore, 
may have been at work in the past, according to geological 
age and local surroundings, yielding at times other minerals 
besides those commonly associated with the salt masses, we 
have in phenomena now surrounding us an explication of the 
conditions under which and the means by which the salt 
deposits of past times were formed. 



100 



CHAPTER VI. 

NITRATE OF SODA, BORAX, BARYTA, GYPSUM, FLUOR 
SPAR, AND ALUM SHALE. 

Composition of Nitrate of Soda Occurrence in German Salt Mines 
Deposits of in Peru and Chili The Desert of Atacama Statistics of 
Production Boron Boracic Acid Composition of the Lagoons of 
Tuscany Borax The Tincal Trade of Thibet Borax in Nepaul, in 
Iceland, and in Nevada Barium Baryta Sulphate Carbonate 
Sulphate of Baryta in Snailbeach Lead Mine The Wotherton Baryta 
Mine, Shropshire Statistics of Production Gypsum, its Composition 
and Varieties Geological Position Statistics of Production Fluor 
Spar in Derbyshire and in Devonshire Native Alum Alum Shale 
Alum Industry on the Yorkshire Coast Description of the Deposit. 

NITRATE OF SODA. 

NITRATE of soda consists of nitric acid 63-5, and soda 36'5. 
It crystallises in a rhomboidal form, like carbonate of lime. It 
burns vividly with a yellow light and deliquesces, in which it 
differs from saltpetre (nitre). 

In most of the German and Austrian salt-mines, nitrate of 
soda occupies a position overlying the salt deposit, the upper 
portions of the beds differing in this respect from the lower. 
The great source, however, from whence it is derived, is the 
great desert of Atacama, South America, lying between 20 
and 27 S. lat., and forming part of the territories of Peru and 
Chili. 

This region is divided into four basins or sub-divisions. 
The eastern boundary of the whole is the great mountain chain 
of the Andes, and the basins are divided from each other by 
mountain ridges running roughly east and west from the Andes 



GREAT DESERT OF ATACAMA. IOI 

to the sea. Starting from the north, the first basin is bounded 
on the north by the hills Caracoles, Atacama, and Naguayan. 
This basin communicates with the Pacific by the deep gorge 
of Negra, near Antojagasta. This is separated from the next 
region to the south by a range of hills and the peak of Cobre. 
This second basin is named Cachiyuyal, and towards the sea it 
opens out into the port of Taltal. It contains the most ex- 
tensive tracts of level ground to be found in Chili. The 
third basin is not so large, and it is bounded on the south by 
the hills that extend to the Cerro Negro and Carrizalillo. It 
consists more of a series of narrow valleys than of plains to any 
extent. The fourth basin consists of the dry bed of the Salado 
River and the undulating stretches of land that bound it. The 
strike of the underlying strata of the whole region is roughly 
from north-east to south-west. The oldest rocks, consisting of 
granites, gneiss, slaty rocks, and limestone, rise up in the 
mountains to the east. Over these older rocks the newer 
deposits, consisting of gravel and sand, the waste of the ad- 
jacent rocks, are spread, and the characteristic feature of the 
whole region is its barrenness. 

The deposits of nitrate of soda are mainly scattered over 
the portion of this region lying between 24 and 26 30' S. lat. 
They occur at a little distance from and along the course of 
ancient river beds. The deposits form layers about 8 to 10 
inches in thickness, and they usually underlie a bed of common 
salt. The richest portions occur near the margin of the de- 
posits. The existence of the mineral under the surface is 
indicated usually by numerous natural pits leading down to it. 
The production of nitrate of soda in the Peruvian portion of 
the region in 1879 was stated at 55,000,000 pounds. It is esti- 
mated that the portion of the desert situated in Chilian territory 
contains enough of nitrate of soda to yield 10,000,000 pounds 
a year for a century to come. It is probable that, as similar 
conditions prevail, similar deposits will be found spread over 
the great salt desert of the Argentine Republic, 25 to 30 S. 
lat., 64 to 68 W. long. 



102 EARTHY AND OTHER MINERALS. 

BORON, BORACIC ACID, BORAX. 

Boron is one of the simple elements. It is not abundant 
in nature, where it is only found in combination with oxygen 
as boracic acid. It was first discovered by Sir Humphrey 
Davy in 1807, by exposing boracic acid to the action of a 
powerful voltaic battery. Gay-Lussac and Thenard afterwards 
obtained it in greater quantity by heating boracic acid with 
potassium. In the year 1851 boron was obtained by Deville 
ist, in the form of transparent crystals resembling the 
diamond, but generally of a reddish tint, and in this state he 
considered it the hardest of all substances known ; it scratched 
the diamond with ease ; 2nd, in metallic crystals resembling 
graphite ; and 3rd, as a black amorphous powder. 

Boracic Acid consists of three parts of hydrogen, one of 
boron, and three of oxygen. It is largely obtained from 
lagoons in Tuscany. The rocks around these lagoons are 
Cretaceous limestones and Tertiary clays, and are in various 
stages of decrepitation from the action of the vapours arising 
from the lagoons. The vapours are often very dense, with a 
strong sulphuretted hydrogen smell, and the lakes are often 
restless. 

In the year 1818 Mr. Frangois Lardarel, a French gentle- 
man, founded a small establishment for the collection and 
extraction of boracic acid, and in 1827, being led to practise 
economy through the great cost of firewood, he turned to 
account the hot vapours of the lagoons. His trade grew until 
he had nine establishments within a few miles of Castelnuovo. 
The production increased from 521 tons in the ten years 
ending 1828 to 1,831 tons in the year 1859. 

Borax, Borate of Soda, is composed of boracic acid 36-58, 
soda 16*25, and water 47*17. Occurs in white crystals, and 
has a sweetish alkaline taste. Crude borax, or tincal, is found 
in Thibet, over extensive districts. Considerable quantities are 
dug out of the earth, and many of the people, shepherds chiefly, 
are employed in collecting it. Large quantities are obtained 
from the lake Pelto, and from another lake distant about one 



TINCAL TRADE OF THIBET. 103 

hundred miles to the east of this. This more distant lake is 
described as being difficult of access, being surrounded by 
precipitous rocks. It is supplied chiefly by springs, the waters 
of which hold borax in solution. The water evaporates and 
leaves a crust of borax covering the bottom of the lake. This 
process goes on continually, so that there is a constant supply. 
The ground over large areas is also strongly impregnated 
with it. 

The substance is collected from the sides of the lakes in 
the months of September, October, and November, when it is 
carried by flocks of sheep, about 30 pounds on a sheep, to 
the villages, where it is packed in bags woven by the shepherds, 
and further carried at a very slow rate over difficult roads to 
Moradabad, where it is bought by native merchants and sent 
by them to Calcutta. 

A deposit has also been discovered in Nepaul, consisting 
of very fine crystals and comparatively pure. A lagoon has 
also been discovered in Iceland, and, as I write, the prospectus 
of a company just formed to work it is issued. 

A similar lake exists in Esmeralda country, Nevada, United 
States of America, in a valley known as Teel's Marsh. This 
was discovered as lately as 1873, and a great industry has 
arisen in connection with it. It appears as a soft clayey 
deposit, and it is said, after removal, to renew itself in two or 
three years. 

BARIUM, BARYTA. 

BARIUM, another of the simple elements and the metallic 
base of barytes, was also discovered by Sir H. Davy, in the 
year 1808. It is a white metal like silver, and is fusible below 
a red heat. It takes its name from (3apv<s, heavy, on account 
of the density of some of its compounds. 

BARYTA consists of about equal parts of barium and oxygen. 
It is a grey powder with a specific gravity of about 4. 

SULPHATE OF BARYTA (Heavy Spar). Composition : baryta 
66, sulphuric acid 34. H. = 2-5 to 3-5 ; specific gravity 4-3 
to 4*8. Of a white colour, frequently tinged yellow, red, or 



104 EARTHY AND OTHER MINERALS. 

brown ; occurs in compact, granular, fibrous, and columnar 
masses ; is translucent to transparent, with a vitreous lustre. 
It decrepitates before the blow-pipe, and fuses with difficulty. 

CARBONATE OF BARYTA ( Witherite]. Composition : baryta 
76'6, carbonic acid 22*4. H. = 3 to 375 ; specific gravity 
4-29 to 4'35- Crystallises in six-sided prisms with terminal 
pyramids, and exists also in fibrous or granular masses. Colour, 
white, yellowish, and grey, and a rather resinous lustre. The 
crystals are usually white and transparent. 

Baryta occurs in the Llandeilo and Bala beds of the Lower 
or Cambro-Silurian strata. It is found associated with lead 
ores. At the Snailbeach lead-mine, in Shropshire, it occurs in 
beautiful crystalline forms. It is, however, in the higher beds 
of these strata, where the lead fails, that baryta is most 
abundant. The Wotherton mine, on the borders of Shropshire 
and Montgomeryshire, is one of the most productive baryta 
mines in Great Britain. Here the lode is from 3 to 30 feet wide. 
It crosses a band of hard rock of considerable thickness diago- 
nally from east to west, and it is in this hard rock that the lode 
is most productive. When it passes at each end into soft slate 
or shale, it becomes disorganised, and the baryta is in a more 
scattered form. In the productive portion the lode consists 
of great masses of pure white sulphate of baryta, mixed with 
others coloured yellow. Some very perfect crystals occur in 
cavities in the masses, some of which are the more interesting 
because they show the method of their growth by accretion, 
in the layers coloured by different metals. There are also fine 
crystals of carbonate of lime which are similarly coloured. 
There are also here and there spots and nests of the sulphides 
of copper and lead. This mine yielded 3,328 tons in the year 
1 88 1. Three mines in Northumberland and Durham yielded 
5,434 tons, including a considerable proportion of carbonate 
of baryta. One in Yorkshire, Raygil, gave 2,017 tons > an d 
forty-four in Derbyshire a total of 5,140 tons. The baryta 
from the four last-named counties came from the strata of the 
Carboniferous Limestone, in which it was also associated with 
lead-ores, where it is found at a depth of from 70 to 100 feet 



GYPSUM. 105 

below the ordinary gypsum. In Great Britain and Ireland 
there were, in the year 1881, seventy-two mines, with a total 
production of 21,313 tons. The sulphate of baryta is ground 
for the manufacture of paint, and the carbonate, which is a 
poison, is used among other things for the destruction of rats. 

GYPSUM SULPHATE OF LIME. 

We have already noticed carbonate of lime as constituting 
the bulk of limestone rocks, but another form, sulphate of lime, 
occurs abundantly in nature. The general composition of 
gypsum is, lime 32*6, sulphuric acid 46 '5, water 20*9. H. 1*5 
to 2-0, and specific gravity 2-31 to 2-33. In a pure and crys- 
tallised state it is clear and translucent, with a pearly lustre ; 
but according to the degree in which it is mixed with other 
minerals, it is grey, yellow, brown, and black, and is opaque. 
It crystallises in right rhombic prisms with bevelled edges. Its 
varieties are 

ANHYDRITE (Anhydrous Sulphate of Lime] differs from ordi- 
nary gypsum in that it does not contain water. Chemical com- 
position: lime 41*2, sulphuric acid 58*8. Occurs at the salt-mines 
at Bex, in Switzerland, where it is found at a depth of from 70 
to 100 feet below the ordinary gypsum ; Hall, in the Tyrol, 
at Ischil in Upper Austria, and at the great salt-mine of 
Wieliezka, in Austrian Poland. It is sometimes used as an 
ornamental stone. 

Fibrous Gypsum or Satin Spar, composed of fine white 
fibres. 

Radiated Gypsum, having as its name indicates a radiated 
structure. 

Selenite, which includes the foliated transparent gypsum. 

Snowy Gypsum and Alabaster, the latter being the name 
by which the massive form of gypsum is known. 

Sulphate of lime occurs in most geological formations, from 
the oldest Silurian to the newest Tertiary. It is, however, most 
abundant in the upper or Keuper division of the Triassic strata. 
We have already seen, in treating of salt, how largely it is 
associated with that mineral in almost every salt district de- 



106 EARTHY AND OTHER MINERALS. 

scribed, occurring generally in nests, pockets, and irregular 
masses above the salt deposits, and in one instance, that of 
Droitwich, forming a continuous bed 40 to loofeet thick above 
the liquid brine. 

In the year 1881 there were sixteen gypsum mines at work 
in Great Britain and Ireland. These returned a total pro- 
duction for the year of 79498 tons, of the estimated value 
23,3297. Of this quantity, three mines in Derbyshire yielded 
12,928 tons, nine mines in Nottinghamshire yielded 49,604 
tons, three mines in Staffordshire 7,456 tons, and one mine in 
Sussex 9,510 tons. Formerly the great source of gypsum was 
the Chellaston Plaster Mine in Derbyshire ; but its production 
had fallen off in the year 1881 to 790 tons. 

It is estimated that from 30,000 to 40,000 tons are used 
annually in Great Britain, chiefly in the Staffordshire potteries 
for making plaster moulds ; hence it is often called ' potters' 
stone.' 

In France, gypsum is worked chiefly at Montmartre and 
Pantin, in the Paris basin of Tertiary strata. It is harder than 
the English gypsum, and as plaster of Paris it is more valued 
on this account. 

As alabaster, gypsum is worked in several parts of Italy. The 
purest is that of Val di Marmolago, near Castellina, thirty-five 
miles from Leghorn, and it is much used for ornamental pur- 
poses. A fine variety, resembling white wax, is also obtained 
from Valterra, and a granitic variety is obtained from Carrara. 

In America, selenite and snowy gypsum occur in New 
York, near Lockport ; and in the Mammoth Cave, Kentucky, it 
occurs in beautiful imitations of flower, shrub, and tree foliage. 

FLUOR SPAR. 

FLUOR SPAR {Fluoride of Lime) is composed of: lime 
5i'3, and fluorine 48*7. It occurs in compact and granular 
forms ; is sometimes fibrous. It ranges in colour from white 
through yellow, light green, purple, blue, and more rarely rose 
red. The colours are usually bright, and in the massive 
varieties they are frequently banded. It frequently forms the 



FLUOR SPAR, ALUM. 107 

gangue or matrix of the metallic ores in mines, especially in 
lead-mines in limestone, and it is found occurring in veins in 
the older gneissic, granitic, and slaty rocks. 

There are three mines in England producing fluor spar 
two in Derbyshire in the Carboniferous limestone, yielding in 
1 88 1 122 tons, and one, the Tamar Silver Lead, in Devonshire, 
worked in the older slaty rocks, which produced in the same 
year 250 tons, the value being about 14^. per ton. 

NATIVE ALUM ALUM SHALE. 

Native alum occurs in silky fibrous masses, and also in octa- 
hedrons and efflorescent crusts. The usual composition is : 
2.4 parts of water to i part of sulphate of alumina, and i part of 
some other sulphate. In the common alum of the shops, potash 
alum, this sulphate is a sulphate of potash. In soda alum it is 
sulphate of soda; magnesia alum, sulphate of magnesia; am- 
monia alum, sulphate of ammonia ; iron alum, sulphate of iron ; 
manganese alum, sulphate of manganese. Alum is manufactured 
largely in England from alum shale, of which in the year 1881 
4,950 tons were raised in Lancashire, 52 tons in Warwickshire, 
2,651 tons in Yorkshire, and 8 tons in Scotland. 

The raising of alum shale, and the production, is an old 
industry in Yorkshire. In 1460 Sir Thomas Challoner brought 
over a workman from France to carry out in England at 
Guisbro' the then secret process, the monopoly of the trade 
being in the hands of the Pope. 

The works afterwards passed into the possession of the 
Crown, and were declared to be a royal mine. They were 
subsequently let to Sir Paul Pindar, at a rental of 15,0007. a 
year. He employed 800 persons and made large profits, the 
price being then 26/. per ton. During the Commonwealth the 
mines were restored to their original owners, and five manu- 
factories were at work. 

The chief quarrying of alum shale now takes place near 
Whitby, in Yorkshire. Overlying the deposit, which occurs in 
Liassic strata, is a bed of hard compact stone called Dogger. 
Below this comes a thick deposit, between two and three hundred 



108 EARTHY AND OTHER MINERALS. 

feet thick, of hard shaly clay, of a bluish grey colour. At a 
considerable depth from the surface this is as hard as ordinary 
slate, but on exposure to the weather the hardest portions 
crumble and decompose. The upper part of the deposit is soft 
and has an unctuous feel. Lower down the deposit becomes 
dull and earthy, with an admixture of sand and of ironstones, 
but below it again assumes its softness and unctuousness. The 
parts of the deposit which are more earthy than slaty yield the 
most alum. The whole deposit abounds with sulphur in the 
form of iron pyrites, but sulphur is more abundant in the upper 
part, which is the most valuable part of the deposit. 



iog 




CHAPTER VII. 

PHOSPHATE OF LIME. 

Phosphorus Importance in Vegetable and Animal Life Use in Agricul- 
tureMode of Occurrence in Nature Phosphoric Acid Apatite- 
Other Forms of Phosphate of Lime Professor Henslow and the 
Coprolites of Suffolk Modes in which Phosphate of Lime occurs in 
Nature The Apatite Deposits of the Laurentian Rocks of Canada 
Their Range and Manner of Occurrence Particular Examples 
Analyses Particulars of Mining The Apatite or Phosphate Deposits 
of Norway Range Geological Age Various Modes of Occurrence 
Particular Examples Rutile Rock Dykes Analyses Difficulties of 
Dressing Mining Particulars. 

PHOSPHORUS is one of the simple elements. It was discovered 
as such in the year 1669, by Brandt, of Hamburg, and in 1769 
Scheele discovered its presence in the bones of men and 
animals. 

Since the last date it has been found to be a most important 
and essential ingredient of the brain, and to be necessary to the 
nervous system generally. It is therefore at the present time 
largely employed in the preparation of medicines for ailments 
affecting these parts and functions of the human body. 

It is present also in considerable proportions in plants, and 
books on agricultural chemistry usually contain numerous 
details of the quantities found in the various plants and roots 
that are used for human food. 

When it is reflected how much phosphorus must be extracted 
from the soil every year to make the bones and tissues of all 
the living things that grow out of and feed upon the earth, it 
will be seen how necessary it is that at least as much phosphorus 



110 EARTHY AND OTHER MINERALS, 

as is extracted from the soil should be returned to it from time 
to time if we would avoid its utter exhaustion. In the attempt 
to do this we have suggested to us the whole question of the 
preparation of chemical manures, into the composition of which 
this substance largely enters. 

Phosphorus is not found in a pure form or free in nature, 
but always in combination with other substances, chiefly lime 
and oxygen. In the mineral state in which we have now to 
consider it, it is found in combination with lime in the follow- 
ing forms, in which it is known as phosphate of lime. 

In all these forms the strength and value of the mineral is 
calculated according to the amount of phosphoric acid there is 
in combination with the other minerals. The composition of 
phosphoric acid is as follows: phosphorus 31 parts, oxygen 
64 parts, hydrogen 3 parts. 

APATITE. Chemical composition: phosphate of lime 91 to 
92, chloride of calcium 0*0 to 0*42, and fluoride of calcium 4-6 
to 77. This mineral has a specific gravity of 3*16 to 3^25, 
that is to say it is about three and a quarter times as heavy as 
water, and its hardness is = 5. In appearance it is often trans- 
parent ; its natural colour is a creamy white, but it is generally 
tinged yellow, light green, grey, and blue, by the admixture of 
various substances that enter into its composition. Its varieties 
are known as 

Phosphorite, which is the general rocky or massive form in 
which the mineral is found, as described more particularly 
further on. 

Magnesia Apatite, which contains 774 of magnesia. This 
variety is found at Kusinsk, in the Ural Mountains, but 
magnesia often enters into the composition of phosphatic 
deposits. 

Moroxite, which is apatite of a greenish blue colour and 
opaque character, from Arendal, in Norway. 

Asparagus Stone, which occurs in translucent crystals of 
a reddish colour, and is found in the Zillerthal, in the 
Tyrol. 

It will be seen in the following pages that the commercial 



PRODUCTION AND USE OF PHOSPHATE OF LIME. 1 1 I 

value of the phosphates of lime of commerce is principally 
determined by the amount of phosphoric acid they contain in 
conjunction with lime. 

It was in the year 1842, when on a visit to Felixstow, in 
Suffolk, that the attention of the late Professor Hen slow was 
directed by a countryman to the existence of curiously shaped 
nodules or concretions in the red crag of that neighbourhood. 
On examination the Professor found that these nodules con- 
tained a considerable proportion of phosphate of lime, and at 
the meeting of the British Association in 1845, he suggested 
the value of these substances in their application to agri- 
culture. 

The result has been extensive mining operations in the 
original deposits, and also in other deposits of the same sub- 
stance which have subsequently been discovered in other 
parts of this country and in various countries of the world, 
together with a corresponding growth in the manufacture of 
chemical manures. To such an extent has this industry grown 
within the last thirty-five years, that in the year 1875 there 
were raised in England and Wales 250,152 tons of phosphatic 
nodules and substances of the value of 628,ooo/., besides which 
we imported 100,258 tons. In 1877 the home production had 
fallen down to 69,000 tons, our manufacturers depending chiefly 
upon foreign supplies. The port of Charlestown supplied in 
that year no less than 170,000 tons, with a.bout 70,000 tons 
derived from other countries. 

Phosphate of lime is contained in rocks of all ages and of 
almost all textures. It occurs as chemically mixed throughout 
the mass of rock, as collected in a purely mineral form in 
cracks, cavities, and layers of the strata, and also as gathered 
into and forming a good part of the fossil remains contained 
in strata, as well as in beds in which the phosphatic matter of 
ancient sea organisms has been re-deposited upon the old sea 
floor. 

I proceed to describe the principal phosphatic deposits of 
the world, beginning with the oldest stratigraphically, and 
ascending to the newest deposits, noticing as we proceed the 



12 



EARTHY AND OTHER MINERALS. 



intervening strata in which the mineral is more widely and 
sparsely diffused. 



PHOSPHATIC DEPOSITS OF CANADA. 

At the base of the whole series of stratified rocks lie the 
Laurentian strata of Canada, the equivalents of portions of 
which are found in the Western Highlands of Scotland, with 
possibly outcrops of the same strata in the promontories of 
Carnarvonshire and Pembrokeshire, in Wales. 

Fig. 12 will afford an idea of the succession of these lowest , 



about 20.000 F _ . 




9 6 7 e S * 3 Z J 

FiG/i2. ORDER OF LAURENTIAN STRATA OF CANADA WITH PHOSPHATIC DEPOSITS. 

I. Speckled hornblendic or pyroxenic gneiss and greenish hornblendic slaty rocks. 
2. Crystallised limestone, White Lake and Bolton's Creek band. 3. Bands of 
white and bluish-grey limestones (Upper Sharbot Lake), interstratified in lower 
part with beds of mica slate. 4. Black hornblendic slates of quartzose gneiss. 
5. Lower Sharbot limestone with interbedded bands of gneissic and hornblendic 
rock. 6. Granitic gneiss of great thickness (8,000 to 9,000 ft.), with apatite. 
7. Crow Lake, Rock Lake, and Silver Lake limestone with deposits of apatite 
near its base. 8. Gneissic strata of great thickness with a thin interbedded band 
of limestone. 9. Bols Lake and Tay River limestone. 10. Gneissic strata of great 
thickness. 

known strata of the earth's crust, as they course from north-east to 
south-west through the provinces of Ottawa and Ontario, in 
Canada, and the explanation of the figure will give a general 
view of their mineralogical characteristics. 

The whole of this vast volume of strata undulates from north- 
west to south-east in synclinal troughs and anticlinal ridges, and 
it is where the ridges of the granitic gneiss, No. 6, with its over- 
lying limestone, No. 7, come to the surface that the phosphatic 
deposits have been chiefly found and worked. The region 
where the deposits have hitherto been most proved lies for 
some distance on both sides of a line drawn from Prince 



APATITE DEPOSITS OF CANADA. 113 

Edward Peninsula on Lake Ontario, north easterly through 
the counties of Frontenac, Leeds, and Renfrew, in the province 
of Ontario, to the river Ottawa, below the island of Callumette, 
and thence through the county of Buckingham, in the province 
of Ottawa. 

The deposits occur in three forms. First, as beds of 
irregular thickness, interposed between the almost vertical 
strata. Secondly, as veins or lodes whose general direction is 
north-west by south-east or at right-angles to the run or strike of 
the strata ; and thirdly, as superficial deposits in the detritus that 
covers the upturned edges of the rocks. These are the result 
of the decomposition of the exposed portions of the strata, the 
blocks and rough crystals of apatite having fallen out of the dis- 
integrating mass of rock, the fragments and remains of which 
now form the loose material surrounding them. 

The discovery of these phosphatic deposits is of com- 
paratively recent date, and to the close of the year 1874 the 
workings on them partook more of the nature of preliminary 
trials than of systematic workings. There were at that date 
one hundred and forty-two ^openings made on deposits in 
North Burgess, the general position of most of which is shewn 
on the accompanying sketch-map, fig. 13. 

These openings consisted chiefly of trenches 10 to 20 
feet long by 4 to 10 feet wide, cut through the superficial soil 
and decomposed part of the solid strata below. Many of 
these openings revealed phosphate in the loose covering, and 
a good many tons were shipped. In this position [the phos- 
phate consisted of loose masses, embedded in a micaceous 
pyroxenic debris, surrounded by a good deal of calcareous 
matter, together with carbonate of baryta. These superficial 
workings were uncertain, not continuously profitable; they 
were soon exhausted, and consequently abandoned. 

Following, however, the indications they afforded down to 
the solid rock, many of them revealed both beds and veins of 
phosphate of lime, some of which have proved continuously 
and profitably productive. 

It was difficult at first to distinguish between a bed and a 

i 



114 EARTHY AND OTHER MINERALS. 

vein, but as the bearing of the strata became understood, the 




veins were readily distinguished by their contrary direction to 
that of the strike of the stratification. 

In order to afford a view of the character of these more 



APATITE MINING IN CANADA. 115 

permanent workings, I will give a few selected descriptions of 
them. 

1. An opening 10 ft. long, 7 ft. wide, and 15 ft. deep, 
revealing at the bottom a bed of green massive apatite, 
varying in thickness from i to 2 ft., and enclosed by dark 
quartzose and micaceous hornblendic gneiss. This bed was 
struck along its course westward in two places within a chain's 
length, where it showed the same character. 

2. A trench 30 ft. long, sunk down to a bed of calcite, 
with a north-east and south-west course that contained crystals 
of apatite of large size. 

3. A similar trench sunk on a parallel bed of calcite of a 
red colour, in which were crystals of apatite grouped together 
in the midst of the carbonate of lime. 

4. Two openings on a bed running east and west, and 
averaging 10 in. in thickness ; a beautifully pure bed of apatite 
of excellent quality. 

It may be observed here that the apatite deposits in 
carbonate of lime have not proved so continuous as those 
enclosed in the gneissic rocks. To the foregoing I will add 
some illustrations of the character of the veins. 

1. An opening 10 ft. square sunk down to an irregular vein 
of green apatite running in a north-west direction and enclosed 
in a rock which is a mixture of carbonate of lime, felspar, mica, 
and pyroxene. 

2. An opening 8 ft. long, 4 ft. wide, and 3 ft. deep, expos- 
ing a vein of green phosphate, bearing north-west, which had a 
thickness varying from 3 in. to 2 ft., and which was enclosed 
in a rock of quartzose granitic nature. 

3. A pit 10 ft. long, 4 ft. wide, and 6 ft. deep, exposing 
a vein of green apatite 6 to 18 in. wide. The apatite is 
here associated with good-sized crystals of whitish coloured 
mica. 

4. An opening 35 ft. long, 4 ft. wide, and 6 ft. deep, 
shewing a vein of green apatite of a thickness of from 2 to 
3 ft. in syenitic rock. 

5. A shaft 30 ft. deep, in a rock of granitic gneiss, down 



Il6 EARTHY AND OTHER MINERALS. 

to a vein of apatite varying in thickness from 18 in. to 17 ft., 
along which a level had been driven for a distance of 85 ft. 
In this distance two smaller veins were seen to branch out of 
the main one. The phosphate occurs in pockets and bunches 
in the vein, the enclosing rock being a quartzose gneiss. From 
these workings about 450 tons of high class phosphate of lime 
had been obtained. The pockets and bunches of apatite are 
usually connected with each other by a leader or string of the 
mineral, but they are often quite cut off and separate from each 
other. 

The examples just given will afford an idea of the nature of 
the phosphatic deposits in Ontario, and the following descrip- 
tion of a deposit in Ottawa will show the similarity of their 
structure at the extreme point north-east at which the deposits 
have been worked. 

The deposit is on the eighteenth and nineteenth lots of the 
twelfth concession of Buckingham. It is situated on the 
Riviere du Lievre, where the rocks rise in a bold cliff about 
100 ft. high. This escarpment of rock is of a similar character 
to those already described granitic gneiss. It is intersected 
by numerous veins of green crystalline apatite, which frequently 
occur in aggregations or clusters of large-sized crystals. One 
of these, which is before me as I write, is as thick as a man's 
thigh. A portion of it yielded 93 per cent, of phosphate of 
lime. The crystals are cemented together by a readily crum- 
bling matrix of cream-coloured carbonate of lime, in which 
smaller crystals of apatite are thickly disseminated. The pro- 
portion of phosphoric acid is usually larger in these crystals 
than in the rough granular masses. 

Care is required in separating these crystals from the 
enclosing substances, which in colour and texture so closely 
resemble the mineral. An instance occurred in which a work 
was carried on for some considerable time, during which several 
thousand tons of pyroxene, which closely resembles the phos- 
phate, was stored for shipment. Instances are not uncommon, 
too, where the phosphate has been thrown upon the waste- 
heaps. This last mistake has arisen from the variable character 



COMPOSITION OF CANADIAN PHOSPHATES. 117 

and colour of the apatite, which certainly here justifies its name, 
which signifies to deceive. 

When first discovered the colour of the mineral was green, 
and all substances not green were rejected, but it is now 
recognised in every shade of colour, the next principal variety 
being red. It is, as I have said, often crystalline ; it is also 
roughly lamellar, and from this form it passes into that of a 
granular condition, known as sugar phosphate. It also occurs 
as a very close-grained compact rock, which has formerly often 
been thrown away as useless. Several blocks of almost pure 
phosphate, weighing upwards of a ton each, were shown at the 
Paris Exhibition. 

The following analysis by Dr. Voelcker will show the 
general composition of the Canadian phosphates, and it is 
seldom that any of a less proportion than 65 per cent, .of phos- 
phate of lime are shipped from Canada. 





No. i. 


No. 2. 


No. 3. 


No. 4. 


No. 5. 


No. 6. 


Moisture, water of 
combination, and 
loss on ignition . 
* Phosphoric acid . 
Lime . . 


62 

33-5I 

4.t)'I4 


10 

41-54 

^4" ~4 


II 

37-68 
^1-04 


1-09 
30-84 
42*72 


8 9 

32-53 
44*20 


'I 3 

31 1 7 

4V62 


Oxide of iron, alu- 
mina, fluorine, &c. 
Insoluble silicious 
matter .... 


7-83 
II-QO 


3-03 

59 


6-88 
429 


I3-32 
12-03 


12-15 
10-17 


9-28 
I3-50 




lOO'OO 


100-00 


100-00 


100-00 


lOO'OO 


100-00 


* Equal to tribasic 
phosphate of lime 


73-15 


90-68 


82-25 


67-32 


71-01 


69-35 



The distinguishing characteristics of the composition of 
Canadian phosphates are the absence of carbonate of lime, the 
scarcity of iron and alumina, and the presence of fluorine. 
They are also rather hard, and somewhat difficult to grind to 
the desired degree of fineness. 

In the early stages of the industry, when the phosphate has 
been picked out of the loose stuff near the surface, it has been 
known to be mined for from 2S. to 2s. 6d. per ton, and large 



Il8 EARTHY AND OTHER MINERALS. 

quantities have been obtained at prices varying from $s. 6d. to 
IQS. per ton. But as the deposits are followed down into the 
hard gneissic rock the cost of mining is considerably increased. 
The rock is very hard, and it soon blunts the drills ; against 
this, however, must be set the fact that frequent joints in the 
rock facilitate operations. The veins are worked by open cut- 
tings, and, where favourable, by means of tunnels, from which 
the veins are followed and stoped away upwards overhand. 

The following is an estimate of the cost of working made 
by Mr. Alexander Garret, of Ottawa, in connection with the 
Riviere Lievre deposit, before referred to, which, although it 
may be subject to variations caused by time and by special 
mineral conditions, will afford a favourable idea of the cost of 
mining Canadian phosphates. Quantity supposed to be raised 
when the mine is fairly opened out, 5 tons a day. 

$ Cents. 

Four men at 120 cents each per day . . . . 4 80 

One cart, horse, and boy 2 25 

Assorting o 75 

Loading on raft o 50 

Freight on raft to Buckingham 2 oo 

to steamboat-landing on the Ottawa . . 7 50 

Wharfage o 60 

Loading on barge for Montreal at $2 50 cents per ton . 12 50 

Discharge into vessels at 10 cents per ton . . . o 50 

Commissions and insurance on 5 tons . 3 oo 

Powder and fuze o 20 

Interest and contingencies o 50 

Loss in transit 75 

35 85 
or $7 17 cents per ton. 

It is assumed in the calculation that the phosphate is equal 
to 80 per cent., and that it is worth in Montreal $20 a ton, so 
that the cost and profit would stand thus : 

$ Cents. 

Value 100 oo 

Cost 35 85 

Profit ..... 64 15 

or nearly 2/. 14^. per ton. 

As, however, the value of the phosphate in Liverpool at 



APATITE DEPOSITS OF NORWAY. 119 

is. $d. per unit would be only 5/. per ton, and the freight from 
Montreal to Liverpool would average 25.$-., the value of the 
mineral in Montreal as given above is placed too high. 
An estimate at another mine is given as follows : 

*-* 

Cost of mining per ton . . . . 150 

Cartage to river 040 

River carriage to Montreal . . . . 040 

Freight from Montreal to Liverpool . . 150 

Cost in Liverpool . . . 2180 

The amount shipped from Montreal in 1883 was 17,840 tons. 

As regards the cost of mining, this estimate seems to be 
most correct of the two. The cost will, however, differ much 
in different localities, owing to the varying thickness of the 
beds, the frequency or otherwise of the pockets, their size, and 
other considerations. It will also vary at different times at the 
same mine. Let us now notice deposits of a similar nature in 
Norway. 

THE APATITE OR PHOSPHATIC DEPOSITS OF 
NOR WA Y. 

The existence of apatite in Norway has been known for a 
long time, and special attention was drawn to it by M. Dufrey- 
noy in his * Traite de Mineralogie.' The discovery of deposits 
which could be profitably worked only dates, however, from the 
year 1871. The discovery was made accidentally by Peter 
Simonsen, who organised a French company to work the 
deposits he had discovered. The explorations of this com- 
pany led to the discovery of a number of similar deposits 
within the same district. The only mines at present worked 
extensively are those which are worked by a French company 
in the parish of Bamle, near Oedegaarden. 

The region of the principal phosphatic or apatite deposits 
known in Norway stretches, as will be seen by a reference to 
the map, fig. 14, from the towns of Stathelle and Langesund, 
west-south-west, to the port of Kragero, and on to Risor and the 



120 



EARTHY AND OTHER MINERALS. 



neighbourhood of Arendal, as shown in the map, fig. 14. I have 
made several visits to this region, and I have examined a great 
number of these deposits. I am enabled, therefore, to supple- 
ment the interesting information given in the article ' referred 
to below from personal observation. 

The section, fig. 15, will show the general order of the 
strata at this region, which belong to the Laurentian group, 




FIG. 14. MAP OF THE APATITE DISTRICT, NORWAY. Scale, 8 English miles = i inch. 

and bear a great resemblance to the strata of the same age in 
which the Canadian phosphatic deposits occur. 

The rock in which the apatite is usually found is a dark 
grey granular gneissic rock, with a large proportion of horn- 
blende in it, the colour being lighter or darker according as 
there is less or more of this mineral. The particles of the 

1 * Vorkommen des Apatit in Norwegen,' Herren Brogger und Reusch. 
Deutschen Geological Gesellschaft^ 1875, p. 646, et seq. 



ILLUSTRATIONS OF APATITE VEINS IN NORWAY. 121 




c a 




FIG. 15. SECTION FROM AAS TO FOSTHI, SHOWING GENERAL ORDER OF STRATA IN 
APATITE DISTRICT, NORWAY. 




FIG. 16. VEINS OF APATITE AT 
TVITRAE, NORWAY. 

A B, Apatite Veins. 

C D, Openings. 

Dark shading, Hornblende. 

Light parts with x, Apatite. 

,, 2, Quartz Strings. 

E E, Gneissic Rock. 




FIG. 17. APATITE VEINS, GODFIELD. 



222, Hornblende, large flakes of Mica, 

and some Titanic Iron Ore. 
3 3, White and Grey Granular. 
4 4, Dark and Grey Granular Rock. 



122 



EARTHY AND OTHER MINERALS. 



different minerals the rock is composed of are less regularly 
arranged than in ordinary gneiss. 

The apatite occurs in veins, as shown in figs. 16, 17, 18 ; 
in nests and pockets, as seen in figs. 19, 20, and 22 fig. 22 
giving a fair illustration of the surroundings of a Norwegian 
apatite mine; and in beds, as shown in the sections, figs. 15, 
23, and 24. The Gabbro referred to in the explanation of 
some of these figures is the name given to darker and rougher 
varieties of the hornblendic gneiss, in which the deposits are 
found. It also occurs in large 
crystals, fig. 22, groups of which 
sometimes take the place of the nests 
and pockets distributed through the 
rocks. The veins do not lie along 
lines of displacement of the strata, 
but are rather cracks of shrinkage 
filled with phosphate and its asso- 
ciated minerals. Fig. 16 repre- 
sents two parallel lodes, about 8 ft. 
apart, at Tvitrae, which can be 
traced along the surface for two 
or three hundred yards, and the 
southern one has been followed to 
a depth of 30 ft. They are from 
3 ft. 6 in. to 6 ft. wide, and the 
apatite, which here is chiefly red 
in colour, with a little yellow, lies 
in pockets and wedge - shaped 
masses within the lodes. These masses are sometimes 4 ft. 
thick and 6 or 8 ft. long, and they are connected by strings 
of apatite and hornblende, sometimes by the latter alone, 
the miner never losing heart as long as he has a string 
of hornblende to follow. The hornblende also surrounds 
the apatite as a black margin from ^ in. to i in. thick. 
These apatite masses are separated from each other by similar 
masses and strings of dull quartz, fig. 21, so that probably 
not more than two-fifths of the contents of the veins are 




212 



Fig. 18. SECTION OF DOUBLE 
LODE, GODFIELD. 



Scale 1 inch 
i i, Apatite with 



i foot, 
occasional 



strings of Quartz. 

2 2, Hornblende (Black) with 

Iron Ore occasionally. 

3 3, Grey Granular Rock. 
4, Hornblendic Gneiss. 



POCKETS OF APATITE NEAR KRAGERO. 



123 



apatite. Figs. 17 and 18 are also illustrations of apatite veins 
as they occur amongst a number of others at Godfield, where 
the apatite is of a cream and greenish colour. Here are the 
usual conditions the grey granular rock, the fringe of horn- 
blende, which on each side of the apatite in fig. 17 contains 
some beautiful crystals of titaniferous iron ore and large flakes 
of mica. In this illustration are also seen examples of pockets 
running alongside the vein. Being simply cracks of shrinkage, 
these veins are uncertain as to their continuance in length and 
depth, and also as to the character of their contents. It is 




FIG. 19. VUGGENS APATITE MINE NEAR KRAGERO, NORWAY, SHOWING NESTS OF 
APATITE, a, a. 

only when a long length is exposed, as at Tvitrae, and at the 
works of the French company near Faesset, that their average 
worth can be estimated. 

In figs. 19 and 20 we have illustrations of the way in 
which the mineral occurs in pockets, and it will be seen that 
the chief thing to be considered in estimating the commercial 
value of such deposits is the proportion of apatite contained 
in the mass of rock to be removed. These deposits are uncer- 
tain in their character. Fig. 20 is an illustration of the 
character of a long cluster of nests about 50 ft. in length, 
which promised to give an average thickness of i ft. of apatite ; 



124 



EARTHY AND OTHER MINERALS. 






H 

> o 
55 1) 

i? 

ir 

W H 



? z 

8> 

58 > 
W 58 
w 



02 

g3 

So 




the strata while lying in the 



but the whole of 
these nests died 
out at a depth of 
a few yards. The 
Vuggens mine, fig. 
19, has been more 
successful. Here 
again the apatite 
is surrounded with 
hornblende, the 
crystals of which 
in all cases point 
in length towards 
the apatite. 

Fig. 23 is an 
illustration of a 
series of bed-like 
deposits on Dore- 
dalen property, 
near the Tvitrae 
Lake. These beds 
crop out on the 
high breast of a 
hill, and are trace- 
able for a con- 
siderable distance. 
There aje six or 
seven of them, 
ranging from 6 in. 
to 2 ft. in thick- 
ness. Possibly, 
however, they may 
not be true beds, 
but collections of 
apatite occupying 
portions only of 
line of bedding. They are, how- 



Speckled 
Gabbro. 



Sandstone 
and Gabbro. 



CRYSTALS OF APATITE NEAR KRAGERo. 125 

ever, the most massive and continuous beds I saw in Norway. 
The apatite here varies in colour 
from cream through green and 
white and pink. At a little dis- 
tance from these beds there is a 
long irregular mass about 30 ft. 
long, lying in the line of the 
stratification and dying out to a 
string at each end. Another in- 
teresting series of bed-like de- 
posits occur near the south-west 
end of the range in the hill H6- 
gaasen, on the Midbo property, 
about half-way between Tved- 
estrand and Arendal. Fig. 24, 
from a sketch taken by me in 
August, 1882, illustrates these 
deposits, which are interesting 
from the amount of rutile oxide 
of titanium associated with the 




Apatite Deposit. 



Speckled Gab- 
bro. 



FIG. 21. SECTION OF APATITE DE- 
POSIT AT OEDEGARDEN. 




FIG. 22. FINE CRYSTALS OF APATITE IN VUGGENS MINE, KRAGERO, NORWAY. 

apatite, as well as for the beautiful separate crystals of apatite. 



126 



EARTHY AND OTHER MINERALS. 



The latter mineral lies in pockets, the run of which coincides 
with the bedding of the gneissic rocks. 

The following analysis by Dr. Voelcker of two samples 
each of red and of white will give an idea of the rich quality 
of these Norwegian apatites. 




FIG. 23. HILL-SIDE ON DORFDALEN PROPERTY, NORWAY, WITH APATITE BEDS 
(A A A) SET IN GREY HORNBLENDIC GNEISSIC ROCK. 





Red Apatite. 


White Apatite. 


Hygroscopic water 


0'43 

0-40 
41-88 

53-45 
1-61 

1-66 
1-24 


0*43 
0-40 

4174 
54-12 
1-61 

0-20 

0-45 
0-97 
0-50 


0*19 
0-23 

4I-25 
56-62 
6- 4 I 
0-29-) 

0-38J 
0-82 
0-17 


0-298 
0-198 
42-280 
53-350 

2-160 
0-920 

0-990 


"Waiter of combination 


Phosphoric acid . ... 




Chloride of calcium 
Magnesium 


Iron and alumina 


Insoluble matter 


Alkalies . . . . 




100-67 


100-00 


100-36 


100-196 



From the absence of all traces of the remains of organic 
life in the apatites of Canada and Norway and in their sur- 



BEDDED APATITE DEPOSITS NEAR TVEDESTRAND. 127 

roundings, we may reasonably infer that in them we have 
original deposits of apatite from phosphatic matter disseminated 
in the water of those early seas, derived probably from gaseous 
emanations and eruptions from the interior of the earth, and 
deposited pure and simple, without having passed through the 
structure and substance of living organisms. The gathering of 




irwr 



FIG. 24. SECTION OF APATITE DEPOSITS AT MIDBO, NORWAY. 

A A A A, Red and Grey Gneissic Strata. 

B B B B, Dark-coloured Hornblendic Gneiss bounding the Apatite Courses C C C C. 

i, 2, 3, 4, Openings on the Apatite Courses. 

the mineral into separate masses distinct from the rest of the 
strata, with the crystalline fringe of hornblende and titaniferous 
iron ore, indicates considerable chemical action with its result- 
ing crystalline conditions subsequent to these depositions of 
the phosphatic matter. 

The containing gneissic rock is often varied by passing into 



128 EARTHY AND OTHER MINERALS. 

large masses of pink and red felspar, especially in the imme- 
diate vicinity of the apatite pockets. Dykes of the same 
substance, and also of granite, not unfrequently cross the strata 
and cut off the veins. Illustrations of this occur at Godfield. 

The chief element of uncertainty in the mining of these 
deposits lies in the proportions of apatite there may exist to the 
enclosing matrices, and this, of course, depends upon the size 
of the nests and bunches of apatite, and the distances at which 
they may lie apart. 

A difficulty also occurs in the dressing, from the great 
similarity there is between the red felspar and the red apatite, 
and between the white apatite and the white quartz. It 
requires some degree of handling and of familiarity to the eye 
to distinguish the difference. It is also next to impossible in 
actual mining to secure the whole of the apatite. It is tender, 
and in the process of blasting it gets broken up. Even with 
the most careful screening and picking it is impossible to avoid 
having a second quality of the very small of from 45 to 50 per 
cent., and after all some portion is lost. 

It will be seen that with deposits so uncertain in their 
character it is difficult to fix the costs of mining and dressing 
the mineral. It may be assumed that miner's wages are less 
in Norway than in England, but that this is balanced by the 
rather higher price of materials. Then it may be taken that 
an area or space of apatite 6 ft. by 6 ft. by 4 in. thickness is 
equal to a ton, and also that the whole of this in mining cannot 
be saved for use. Taking apatite of the quality of 85 per cent., 
and an average thickness over a considerable area of 8 in., 
and a production of from 1,000 to 1,500 tons a year, the cost 
of mining, dressing, and shipping a ton of apatite, including 
cost of management and all other costs, if the mine is within 
four or five miles of a port, may be taken at 6$s. It is essential 
to success in apatite mining in Norway that a large number of 
concessions be grouped under one management, not only in 
order to save in cost of management, but also that when one 
mine is poor another may be rich, and the supply be kept up. 



CHAPTER VIII. 

PHOSPHATE OF LIME continued. 

Phosphatic Matter in Strata between the Laurentian and Lower Silurian 
The Phosphorite Deposit of North Wales Discovery Range Asso- 
ciated Strata Description of Bed Supposed Origin of Analyses 
Compared with other Phosphates Particulars and Costs of Mining 
and Dressing The Phosphatic Deposits of Estramadura, Spain 
Position Discovery Composition Description of Particular Deposits 
Deposits in Canada, France, Hungary Bone Bed at Top of Upper 
Silurian Strata in Shropshire. 

DEPOSITS IN SILURIAN STRATA. 

BETWEEN the deposits of phosphate of lime described in the 
last two chapters and those now to be described there is a 
vast thickness of strata, probably not less than 70,000 to 
80,000 feet in thickness, comprising the uppermost beds of the 
Laurentian group, the whole series of the Cambrian, and three- 
fourths at least of the Cambro-Silurian or Lower Silurian groups 
of strata. 

Throughout the whole of this vast series of rocks there are 
traces of phosphatic matter, which becomes an appreciable 
quantity where organic remains abound, as in the Paradoxides 
beds of St. David's, the fossiliferous beds of the Lingula strata, 
and of the Llandeilo limestone. 

At nearly the summit of the Cambro-Silurian strata in 
North Wales, and resting on the uppermost surface of the Bala 
limestone, we meet with a deposit of phosphate of lime, which 
is interesting scientifically, and which, although it has not yet 
been extensively worked, is, I think, from its position, quality, 
and the great extent of the deposit, destined to be. 

K 



130 EARTHY AND OTHER MINERALS. 

Dr. Voelcker, who had been employed to make analyses of 




some samples of the deposit for the original discoverers and 



SECTIONS OF STRATA IN NORTH WALES. 131 




FIG. 26. SECTION ACROSS THE BERWYN AND ARRAN MOUNTAINS, N. WALES, ON LINE A B 
OF PLAN. Scale 5" = i mile. 




SECTION ACROSS THE BERWYN MOUNTAINS, N. WALES, ON LINE B C OF PLAN. 
Scale J" = i mile. 

i Hirnant Limestone. 2, Bluish Shales. 3 3, Shales with Phosphatic Nodules. 4, Phos- 
phorite Bed. 5, Bala Limestone. 6, Bala Ash passing into Greenstone. 



132 EARTHY AND OTHER MINERALS. 

workers, first directed public attention to it at the meeting of 
the British Association held in Birmingham in the year 1865, 
when he entered into particulars concerning its composition 
and value. In the year 1867, having been previously em- 
ployed in the examination of the deposit at points east and 
west of the place of original discovery, I communicated a 
paper to the Geological Magazine? in which its true strati- 
graphical position and mineralogical conditions were first 
described. 

Subsequently, in 1871, a discovery was made of a similar 
bed near the summit of the Berwyn Mountains, between Llan- 
gynog and Bala, with which I became connected, and having 
had occasion to examine the deposit at various other points 
of discovery, I embodied the whole of my observations in a 
communication made to the Geological Society in 1874, and 
which appeared in the journal of that society during the fol- 
lowing year. 2 

I will here summarise those observations, and add such 
particulars of results and cost of working as will illustrate the 
value of the deposit, and which will, I hope, be of service to 
those who may hereafter attempt its working. 

The deposit, as shown on the sketch-map, fig. 25, follows 
the course of the Bala limestone in the north-east part of the 
county of Montgomery, North Wales. The section, fig. 26, 
along the line A B C of the map, illustrates the general struc- 
ture of the county, and shows the phosphate bed with its 
underlying limestone in the same position over the whole 
area. 

Although not essential for our purpose, it will be interesting 
to note the detailed structure of the Bala limestone as it is 
seen at the Berwyn phosphate mine, inasmuch as probably it 
forms the most complete detailed section of that series of beds 
in North Wales. 

1 ' On a bed of Phosphate of Lime in North Wales.' D. C. Davies. 
Geological Magazine, vol. iv. p. 257. 

2 D. C. Davies 'On the Phosphatic Deposits of North Wales,' Quarterly 
Journal GeoL Society, vol. xxxi. p. 357. 



SECTION OF STRATA AT THE BERWYN MINE. 133 




134 EARTHY AND OTHER MINERALS. 

a Grey shale with echinoderms and other fossils phosphatised. 

b PHOSPHATE BED. 

c Dark limestone impregnated with phosphatic matter. 

d Dark shales with veins of sulphate of baryta, passing upwards into a 

soapy clay. 

e Limestone with veins of sulphate of baryta. 
/ Dark shales. 
g Bluish grey limestones. 
h Limestones and shales, often pyritous and decomposing towards the top 

as brownish sandstone, containing fossils orthis and lepteena of several 

species, also trilobites illaenus and asaphus. 
x Blue slaty bed. 

j Limestones and shales with fossils, orthis, lepttzna, bellerophon, &c. 
k Crystalline limestone. 

/ Tough blue shaly rock with limestone partings. 
m Limestones with the usual fossils, plentiful. 

n Beds of bluish shale with black balls of phosphate and small trilobites. 
o Kaolin. 

p Tough calcareous shales, fossiliferous. 
q Kaolin. 

r Alternations of slaty, calcareous, and arenaceous beds, 
j Limestone, composed almost entirely of orthis spiriferoides. 
t Shaly beds slightly calcareous, with limestone bands. 
u Superficial drift. 
x Peaty deposits. 

There is a great similarity of structure in many respects 
in this group of beds all over the district under considera- 
tion. 

The phosphate bed lies at the top of the series of lime- 
stone beds, and is overlaid by the shales, a. It varies in 
thickness from 6 to 18 inches. It is black in colour from the 
graphite it contains ; rarely, where the graphite is absent, it is 
of a pale yellow colour. The bed is made up of a number of 
concretions, which range in size from that of an egg to that of 
a full-sized cocoanut, which are closely packed together, and 
run into each other. They are cemented together by a black 
shaly matrix. The concretions have often a polished appear- 
ance, which is also due to the presence of graphite. Fre- 
quently, along the course of the bed, the phosphorite is 
charged with concretions and crystals of sulphide of iron. 



THE PHOSPHORITE BED OF NORTH WALES. 135 

Near the surface the pyrites become oxidised, and the deposit 
changes its black for a rusty appearance. 

The concretions contain from 60 to 69 per cent, of phos- 
phate of lime j but the matrix also contains a portion, so that 
the average quality of 1,000 tons sent off from this mine has 
been about 46 per cent. 

Latterly, by more careful dressing and selection, the quality 
has been brought up to 55 per cent., and there need be no 
difficulty in sustaining this average. With proper appliances 
and means for drying the phosphate, the percentage may be 
increased to 58 or 60. 

The bed is underlain by a thin bed of crystalline lime- 
stone, c, which does not usually exceed 6 inches in thickness, 
although at times it does thicken out and form a solid lime- 
stone 2 feet thick. This limestone contains phosphate of lime 
to the extent of 15 to 20 per cent. 

Sometimes the phosphate bed is seen to divide into two, 
and more rarely, at the Berwyn mine, fig. 27, into three beds. 
When this division takes place the dividing substance is the 
phosphatic limestone. The uppermost bed dies out as it 
enters the shales ; so does the middle one. It is invariably 
the lowest bed which is continued forward, the overlying lime- 
stone dying out until the shales take their true position above 
the phosphate bed. 

In attempting to account for the existence of this bed we 
cannot be far wrong, I think, in ascribing to it an organic 
origin. It is probably an old sea bottom, on which the phos- 
phatic matter of crustacean and molluscan life was precipitated 
and stored during a long period, while certain marine plants 
may also have contributed their share of phosphatic matter. 
There may also, as in the case of the Laurentian deposits, 
have been an abundance of phosphatic matter in the water of 
this early sea, independent of the living organisms which it 
sustained. 

If we could bend down the edges of the strata of the 
section, fig. 26, to a horizontal line, and piece them with the 
middle portion, which has been broken and denuded through 



136 



EARTHY AND OTHER MINERALS. 



the upheaval of the underlying porphyries, greenstones, and 
slates ; if we further follow the phosphorite bed underground 
along the section, fig 26, to where it comes up in altered 
form on the flanks of Aran Mawddy, and measure the length 
of the district described on the map by the breadth thereof, we 
should gain some conception of the extent of the shallow sea 
with its swarms of life in which the bed 
was deposited, covering as it does an 
area of about 150 square miles. Over 
this the depth of the sea must have 
been nearly uniform, and the same 
conditions of life must have prevailed. 
Then I do not doubt that, in some 
shape or other, the bed may be found 
at the same horizon all along the course 
of the Bala limestone in North Wales. 
The bed presents the same general 
appearance at all the points where it 
has been opened upon. To the east, 
about Llanfyllin, however, it becomes 
more sandy and impure, while on its 
western outcrop, about Llan-y-Mawddy, 
the phosphatic matter is largely re- 
placed by sulphur. The figs. 29, 30, 
3 r > 3 2 > 33 w iH illustrate the details of 
the bed and its associated strata at 
widely different places. 

The following analyses and par- 
ticulars will show the character and 
commercial value of the deposit. 
Analysis of nodules : 




So S 



FIG. 28. SECTION SHOWING 
DIVERGENCE OF THE 
PHOSPHORITE BEDS AT 
THE BERWYN MINE. 



Moisture and organic matter 
Insoluble matter .... 
Tribasic phosphate of lime . 
Oxide of iron and alumina . 
Other constituents not determined 



4-200 

22-600 

64-165 

6-890 

2-145 

100-000 






SECTIONS OF NORTH WALES PHOSPHORITE 

Another analysis of nodules gave 69-24 phosphate 
without any pyrites or carbonic acid, and only slight 
sulphuric acid. Five analyses from the bulk of consignments 
from the Berwyn mine previous to 1876 gave an average of 
46-85 of phosphate of lime. 




traces 






FIG. 29. SECTION 'OF 
STRATA AT PEN-Y- 
GARNEDD PHOSPHORITE 

MINE. 



FIG. 30. SECTION OF 
STRATA NEAR PWLLY- 
WRACH, WEST OF CWM- 



FIG. 31. SECTION OF 
STRATA ATTYNTWLL, 
LLANFYLLIN. 



Dr. Voelcker's original analysis of two samples from Cwm- 
gwynen, the place where the bed was first recognised, were 

ist sample gave 64-16 of phosphate of lime. 



2nd 



48-50 



There was no carbonate of lime, some fluoride of calcium, 
alumina, and oxide of iron. 



138 EARTHY AND OTHER MINERALS. 

The darker-coloured contained more graphite and were 
richer in phosphate of lime than the light-coloured speci- 
mens. 

The deposit at Pen-y-garnedd, when properly dressed, 
averaged 46 per cent, of phosphate of lime. 




UWFJf 

a. ws*?' s,* 

o. p - -I 



FIG. 32. SECTION OF STRATA AT GREEN HALL 
PARK, LLANFYLLIN. 






Continuation 

of Phos- 
phorite Bed. 



AT CWM-DYNEWYDD, NEAR 
LLAN-Y-MAWDDY. 



Two samples from near Llan-y-Mawddy, where the phos- 
phate is replaced by sulphur, gave the following results : 



Phosphate of lime 
Sulphur 



2-90 



1-72 

34-20 



ANALYSES OF PHOSPHORITE OF NORTH WALES. 139 

Partly through want of knowledge, and partly through care- 
lessness, some of the early consignments of phosphate from 
Cwmgwnen and Pen-y-garnedd, and later from Berwyn, were 
not properly dressed and selected. The result was a per- 
centage as low as 30, and the Welsh phosphates came into dis- 
repute. 

The following recent analyses from consignments in bulk, 
and which were made by the analysts of the consignees, will 
show what these Cambro -Silurian phosphates can really be 
made to do, while, as I have said, with proper appliances for 
dressing and means to dry the mineral, it may be sent off 4 or 
5 per cent, higher in quality. 

i. Analysis of sample of 5 tons, by D. H. Richards, 
F.C.S., borough analyst of Oswestry : 

Insoluble in hydrochloric acid . . . 31-020 

Water 280 

Lime 32-256 

* Phosphoric acid . . , . . 23-572 

Oxide of iron, &c. . . . . .'*-- 3'686 

Carbonic acid .... . . . 2-220 

Not determined (alkalies, &c.) . ... . 6-966 



loo-ooo 

* Equal to tribasic phosphate of lime . 5 1 -46 

2. Analysis and samples of 8 tons, by Dr. Voelcker : 

Water and loss on heating . . . . 5-49 

* Phosphoric acid 23-25 

Lime 32-70 

Oxide of iron, alumina, magnesia, carbonic 

acid, &c 15*04 

Insoluble silicious matter . . . . 23-52 



100-00 

* Equal to phosphate of lime . . 50-76 



140 EARTHY AND OTHER MINERALS. 

3. Analysis of sample of 8 tons, by Nesbitt & Co. : 

Moisture 0-35 

Water of combination 2-65 

Silicious matter 28-75 

Oxide of iron and alumina . . . . 4-60 

Lime 32-62 

* Phosphoric acid 23-79 

f Carbonic acid 2 -80 

Sulphuric acid 0-96 

Undetermined 3-48 



100-00 

* Equal to phosphate of lime . . 51-95 
f ,, carbonate of lime . . 6-36 

Two subsequent analyses, one of 8 tons, by E. Davies, 
F.S.C., of Liverpool, gave 54*97 ; and one by the analysis 
of Messrs. Newton Keats & Co., of St. Helen's, gave 
55'8o. 

The value of phosphates of lime for agricultural manures 
depends largely upon the absence of oxide of iron and alumina. 
If these substances are present in quantity the phosphate, 
after it has been made soluble, becomes fixed again, or goes 
back to an insoluble state. Further, if there is too much 
carbonate of lime, the quantity of sulphuric acid required is 
very great, owing to the acid attacking the carbonate instead 
of the phosphate of lime. I have therefore been at some 
pains, in order to arrive at the true value of this North Wales 
deposit, to compare it in this respect with others of similar 
strength from various parts of the world. The annexed table 
is the result; and it will be seen that the phosphate from 
North Wales is really superior in these particulars to the others 
with which it is compared. 

In mining the deposit a level is first driven along the bed 
from the hillside. An opening is next made up to the surface ; 
then the bed is taken down by overhand stoping. It is found 
necessary to take from three to five feet of the limestone bed 
below the deposit away first. This is done by blasting ; and 



COSTS OF MAKING THE WELSH PHOSPHORITE. 141 

if strong explosives are used, and care is taken to compel the 
miners to bore deep holes far apart, and to put strong charges 
of the explosive used, this operation may in future be done 
more cheaply than in the past. The phosphate bed is left 
standing for several fathoms in length, and when a sufficient 
area of its under surface has been laid bare, a few shots put in 
between the bed and the overlying shales brings down the 
whole mass, the parting between the bed and the shales 
being very distinct and clean. The whole of the bed obtained 
is taken out of the mine to be dressed, while the limestone is 
used to fill up the space mined below, passes being left at 
frequent intervals for the purpose of throwing the phosphate 
down into the level below. 

The average amount of ground stoped by two men per 
week at the Berwyn mine was, in 1876, 47 square feet forward, 
or a little over i fathom. With the use of stronger ex- 
plosives, as I have said, the amount should be brought up to 
2 fathoms. 

The average cost for fuze, powder, and candles per pair of 
men per week was 4-r. %d. 

The average nett wages made by men at 36^. per fathom, 
the men finding their own stores, was 23^. per week. 

The average production of the bed over a space of 
360 fathoms was 2 tons 10 cwt. of phosphate per fathom, of 
an average strength of 46 per cent. 

The average yield of 53 per cent, quality from the bed 
was, as nearly as I can ascertain, 2 tons per fathom, the 
remainder, although containing a good deal of phosphatic 
matter, being rejected. 

The cost of driving the level was from 4/. IO.T. to 5/. per 
fathom. 

The cost per ton of dressing 586 tons of ore up to an 
average percentage of 46 was 3^. per ton. 



142 



EARTHY AND OTHER MINERALS. 



THE AMOUNTS OF OXIDE OF IRON, CARBONATE OF LIME, AND 
ALUMINA IN VARIOUS SAMPLES OF PHOSPHATES YIELDING 
UNDER 57 PER CENT. OF PHOSPHATE OF LlME. 






-"Oxide 
of 
Iron. 


Alumina. 


Carbonate 
of Lime. 


Insolu- 
ble Sul- 
phate of 
Iron, in- 
nocuous. 


Soluble 
Sulphur 
and 
Fluo- 
rine. 


ll 


Phosphate 
of Lime. 


Boulogne coprolites, 
ordinary quality 


6-24 


5'39 


8-95 




3-'4 


26-I6 


45-I9 


Ditto, superior . . 


I4-38 




.. 





17-62 


54-79 


Cambridge, ditto . . 
Bedford, ditto . . . 


18-70 
5-29 7-24 


7-84 







777 
20-81 


56-87 


Spanish Phosphate . 


14-0 

V 











37-21 


56-19 


German, ditto . . . 
Carolina, ditto . . 
Welsh, ditto . . . 


5-6 
3'99 
i-oi 


3-20 
I -06 


6-61 
9-0 


7-0 





17-80 

not given 
24-81 


56-80 
52-72 
50-08 



Average amount of oxide of iron, carbonate of lime, 

and alumina in seven of the above samples . . 16-61 

Ditto, in the Welsh sample 11-07 

Only about I per cent, each of oxide of iron and alumina. 

There are, without exaggeration, millions of tons of this 
deposit in Montgomeryshire, which, when the prejudices exist- 
ing against its colour and those created by carelessness or 
ignorance in the early days of its mining, are overcome, may 
be brought into the market at a fair profit to those who may 
undertake its exploitation. 



THE PHOSPHATIC DEPOSITS OF ESTRAMADURA, 

SPAIN? 

These important deposits extend from Logrosan by Mon- 
tanches to Caceres, following the line of railway which now 
extends from Estramadura to Portugal. Attention was first 
drawn to them in the thirteenth century by Bowles, an English- 
man, in a description he then gave of the natural riches of the 
country, and in which he gave the name of phosphorite to the 

1 Quarterly Journal, Geological Society, vol. i. p. 52. Ann. des Mines, 
t. v., 1834, p. 175. 



PHOSPHORITE DEPOSITS OF ESTRAMADURA. 143 

mineral, from its property of giving light in the dark when 
thrown upon burning wood. The deposits were referred to by 
Le Play, in 1834, but they were first fully examined and 
described in 1845 by Dr. Daubeny and Captain Widdrington, 
who went into the inquiry as to whether the mineral would pay 
for working and for transport to England. 

The deposits consist of a series of beds intercalated be- 
tween schisty and slaty strata of probably Silurian age. The 
direction is N. 45 E., and they dip down almost vertically 70 
S.E. There is a granitic bed not far below their horizon in 
the strata. At Logrosan these beds are about 40 yards across, 
and the single beds are sometimes worked in open trenches to 
depths of from 25 to 50 yards. 

The beds have been regularly worked since the year 1865, 
and the phosphates imported into Great Britain have been 
estimated to reach on an average as much as 200,000 tons a 
year. 

The deposit contains a maximum quantity of 85 per cent, 
of phosphate of lime near Logrosan and Montanches, and a 
minimum of 50 per cent, near Caceres. The beds are traceable 
for long distances on the surface. They differ from each other, 
and each one differs in composition and structure in different 
parts of its course. In all of them there is the presence of 
carbonate of lime, which in a certain measure forms a guide 
for the discovery of the phosphorite itself. There is iron in a 
quite large enough proportion, as well as of silicic acid. These 
phosphorites vary from a white to a light ochrey colour. The 
following is an analysis by Dr. Daubeny of phosphorite from 
Logrosan. 

Phosphate of lime ".-.,. .81-15 

Fluoride of calcium .. . . . I4'OO 

Peroxide of iron . . . . . 3-14 

Silica . 1-70 

99-99 

The following particular description of the deposits at 
various points will give a further idea of their character. 



144 EARTHY AND OTHER MINERALS. 

1. Jingal. Bed recognised near a mill in the village of 
Jingal, as it is entered from Truxello. Its thickness is about 
4 ft. 6 in. It is followed for a length of about 420 yards, and 
is seen at a still greater distance. 

2. Del Casillon. This bed passes under the church of 
Logrosan, and presents at the gate of the village a mass of 
phosphate 25 feet in thickness, and very pure. For a long 
distance the average thickness of the bed is about 6 feet. 

3. Nostra Senora del Consuelo. A bed cropping out on the 
side of the hill of that name. It is split up into thin beds 
which probably join in depth. 

4. Costanaza. This bed has been followed for a distance 
of more than 2 miles. It passes downwards like the others in 
the Sierra Boyales, and reaches the base of the Sierra de 
Custova, which rises above the village of Logrosan. 

5. Terras Colorado. A bed 2 yards thick, and proved for 
a length of 105 yards, and parallel to the next bed. 

6. Cumbre Bojera. Which is an important bed. 

There are no organic remains in these deposits. It has, 
however, been argued that the presence of carbonate of lime 
indicates an organic origin, and that traces of organic life may 
have been destroyed by the heat evolved in the irruption of 
supposed igneous rocks close by. To this it is sufficient to 
answer that there must have been both carbonate and phos- 
phate of lime present in those early seas before organic life 
could exist, and that these substances represent the cause as 
well as the effect of organic life. 

Similar deposits to those described extend into Portugal. 
They lie, like those of Spanish Estramadura, in schists above 
granitic rocks, and their quality ranges from 65 to 70 per cent. 

While phosphate of lime is not known to occur in workable 
quantities elsewhere in strata of Silurian age, in FRANCE 
nodules of phosphate are found in the calymene beds of the 
slates of Angers. 

In HUNGARY similar nodules are found in strata of the 
same age, and in CANADA such nodules are found associated 
with the Lingulae of the Lingula flags at the base of the Silurian 



BONE BEDS OF SECONDARY STRATA. 145 

rocks. Spherical concretions of a brown or black colour, con- 
taining a good deal of phosphoric acid, are found in Galicia ; 
also in the government of St. Petersburg, and in that of 
Novgorod, in rocks of similar age. 

At the top of the Silurian strata in Shropshire, and just 
below the lowest beds of the Devonian, is a highly phosphatic 
bed, and one that is very interesting scientifically, because it 
contains the oldest known remains of vertebrate life. The 
bones it contains are associated with crustacean remains, but 
hitherto the bed has not been commercially workable. 1 

A similar bed is also found at the top of the Devonian 
strata at their junction with those of the Carboniferous Lime- 
stone, Another bed occurs at the top of the Trias strata, be- 
tween them and the beds of the Lias. In this bed there are, 
in addition to fish and crustacean remains, the bones and exuvia 
of the huge reptiles which had at this stage appeared in the 
order and succession of life. 

There are two bone beds still higher one at the junction 
of the Lias strata with those of the overlying Oolite, and one 
at the summit of the ' Wealden/ and at the base of the Lower 
Greensand. None of these various bone beds have as yet been 
found of sufficient thickness to pay for working; but I men- 
tion them here as interesting from their position at the junc- 
tion of several consecutive groups of strata, and also as forming 
a source from whence may have been derived, by disintegration 
and denudation, some of the rolled and rounded nodules, 
usually known as coprolites, which we shall have to notice as 
occurring in some of the overlying groups of strata. 

1 See papers by the author in Leisure Hour, October, 1877, p. 685, on 
' Fertilizers and Food Producers.' 



146 



CHAPTER IX. 

PHOSPHATE OF LIME continued. 

The Greensand and Gault Position of Bedfordshire and Cambridge Phos- 
phate Beds Localities Description of Beds with Fossil Contents 
Analyses Composition of the Phosphate Bed Derivation of the 
Phosphate Matter The Phosphatic Nodules of Suffolk Conditions of 
taking Phosphate Lands Phosphate Digging Statistics of Produc- 
tions Phosphatic Deposits of the Ardennes and the Meuse in France 
and Belgium Date of Discovery Geological Position Extent 
Characteristics of the Deposits Phosphate Deposits of Bellegarde, 
France Geological Position and Fossil and Mineral Characteristics 
Analyses Phosphatic Deposits of the Cretaceous Strata of Russia 
History of the Discovery of Mineralogical Features Analyses. 

THE PHOSPHATIC DEPOSITS OF THE WEALDEN AND 
CRETACEOUS STRATA.^ 

BETWEEN the summit of the Oolitic strata and the base of the 
massive beds of the chalk there is interposed a series of beds 
of sand and clay which are known as Greensand. These 
beds are subdivided into Lower Greensand, Gault, and Upper 
Greensand. In the counties of Bedford and Cambridge each 
of these subdivisions contains a bed of phosphatic nodules, the 
precise position of which is shown in the section, fig. 34. The 
lowest and perhaps most important of these beds has been 
extensively worked in the neighbourhood of Sandy, and to the 

1 P. B. Brodie, F.G.S., On a Deposit of Phosphatic Nodules on the 
Lower Greensand of Sandy, Bedfordshire. J. J. Harris Teall, The Potton 
and Wicken Phosphate Deposits . Cambridge : Deighton, Bell & Co., 1875. 
' Rock of the Cambridge Greensand,' Harry Seeley, F.S.A., Geological 
Magazine, 1866, p. 302. ' On the Phosphatic Nodules of Cambridgeshire,' 
by the Rev. O. Fisher, F.G.S., Quarterly Journal, Geological Society, 
vol. xxix. p. 52. 



SECTION OF STRATA SHOWING DEPOSITS. 147 
north-east at Wicken and Potton, Bedfordshire. From the 



==E^EE^=M White Chalk with Flints, 1,000 ft. 




Recent Post-Glacial Sands, Gravels, and Clays.") 



Supposed Place of Carolina Phosphates. 

Upper Boulder Clay. 

Middle Sands and Gravels. 

Boulder Clay. 

Age of German Phosphates, River Lahn. 

Norwich Crags Red Crags.| p liocene> 

Coraline Crags, 100 ft. ) 



Bovey Tracey Beds, 300 ft.\ 

L Miocene. 



Glacial 150 ft. 



Leaf Beds of Mall. 



J 



Hampstead, Bembridge, Osborne, and Headon") Upper 
Beds, about 550 ft. thick (Clays and Sands). 5 Eocene. 



Bagshot, Bracklesham, and Barton Beds (Sand, ) Middle 
Clay, and Gravel), about 1,200 ft. thick. } Eocene. 



Place of Suffolk Coprolites. \ 

London Clay, 450 ft. \ Lower'Eocene. 

Place of Thanet Sands and Plastic Clay. J 



White Chalk without Flints, 600 ft. 

Chalk Marl, 100 ft. 

Ely Phosphate Bed. 

Gault, 200 ft. 

Folkstone and Boulogne Phosphate Beds. 

Lower Greensand, about 1,600 ft 
where fully developed. 

Place of Sandy Phosphorite. 
Place of Wealden. 
Oolite. 



FIG. 34. GENERAL SECTION OF STRATA FROM THE SUMMIT OF THE OOLITE UPWARDS, 

SHOWING THE STRATIFIED POSITIONS OF THE VARIOUS PHOSPHATIC DEPOSITS IN 

THE CRETACEOUS AND TERTIARY BEDS. 



section fig. 35 it will be seen that the bed lies at the summit 



148 



EARTHY AND OTHER MINERALS. 



of sands about 50 feet thick, and that it is covered with similar 
sands and ferruginous sandstone. The bed varies in thickness 
from 6 inches at Potton to 2 feet at Sandy Heath. The bed 
is composed of phosphatic nodules and of pebbles in about 
equal proportions, and these are cemented together by ferru- 
ginous sand into a hard conglomerate. The nodules do not 
occur uniformly over a large area, but appear to run in patches, 
being occasionally absent. They vary in size from a pea to a 
hen's egg. They are of all shapes, rounded and elongated, are 
frequently pitted with minute holes on the outside, where they 
are of a light brown colour, but the interior is of a dark brown 



Sands slightly indurated, 3 ft. striped horizontally. 
Coarse ferruginous Sand with hard flaggy Beds. 

Horizontal striped Sandstone with small Pebbles. 
Phosphate Nodule Bed, 2 ft. 

Sandstone, about 50 ft. thick. 



FIG. 35. SECTION OF PHOSPHATE BED ON SANDY HEATH, BEDFORDSHIRE. 

or black, and they often, but not always, enclose organic re- 
mains, casts, and fragments of fossils, chiefly those of ammo- 
nites. The enclosed and associated fossils are much water- 
worn. Of these fossils some about half are derived from 
other strata, about ten species of mollusca from the Portland 
beds, a large number of bones, teeth, and scales of the rep- 
tiles iguanodon and megalosaurus from the Wealden and 
Purbeck beds, with seven species of mollusca and numerous 
teeth and spines of fish from the Kimmeridge clay. The 
extraneous shells are often so rolled and broken as to defy 
recognition. Then about eighteen species of mollusca have 
been identified as belonging to the bed itself, inasmuch as they 
are not rolled or broken. Vegetable remains, including those 
of Clatharia Lyetti, are also found associated with the phosphatic 




ANALYSES OF CAMBRIDGESHIRE COPROLITES. 149 

nodules. The following analysis of the samples referred to by 
Mr. Brodie will show the composition of the nodules. 

Average Samples Washed Copro- 

of Siftings, from lite from another 
layers at i and 2 ft. spot. 

Water of combination .... 5-17 5-67 

Phosphoric acid* 22-39 15-12 

Lime 3 2 '73 26-69 

Magnesia, alumina, and fluorine . . 6-64 4-51 

Carbonic acidf 3-06 2-18 

Oxide of iron 8-08 20-61 

Silicious matter 21-93 25-22 

100-00 loo-oo 

*EquaL to tribasic phosphate of lime . 48-51 32-76 

fEqual to carbonate of lime . . -6-95 4-95 

In the course of working these deposits care has been 
taken to bring the percentage of phosphate of lime as near as 
possible to the highest of these figures, the lowest being com- 
mercially valueless. 

To the north of Cambridge, and near Ely, a similar bed, 
from six inches to a foot thick, occurs in what would seem to 
be a little higher place in the series of strata, resting as it does 
immediately upon the Gault. Thus nodules of this bed are 
richer in phosphatic matter than are those just described, a 
very full analysis by Dr. Voelcker giving the following re- 
sults : 

Moisture and organic matter . f . 4-68 
Lime. . . . . . '. . 43-21 

Magnesia . . . . . . 1*12 

Oxide of iron . * . . . 2-46 

Alumina 1-36 

Phosphoric acid . . . . .25-29 
Carbonic acid . . . . . . 6-66 

Sulphuric acid 0-76 

Chloride of sodium 0*09 

Potash . 4 / l . '' 4 t * .0-32 
Soda. . . . * 4 , 0-50 
Insoluble silicious matter . . . . 8-64 
Fluorine and loss 4-96 

100-05 



150 EARTHY AND OTHER MINERALS. 

The greater part of the nodules seem to have been derived 
from other and older strata. Many of them show the structure 
and markings of the interior of shells of various kinds. All 
the derived fossils have plicatulae attached to them, and even 
where they are broken plicatulae are attached to the broken 
surfaces. They vary in size up to a diameter of four inches. 
Often they are irregular concretions, but frequently occur as 
tubes or halves of tubes. Although of a greenish cast outside, 
when broken they show a dark brown colour, and sometimes 
contain scales of fishes and small shells. 

There are also fragments of bones of birds, reptiles, and 
fishes, all charged with phosphatic matter. As I have before 
hinted, some of these nodules may have been derived from the 
abrasion of older phosphatic beds, whether massive or nodular. 
There cannot, however, be any doubt that the water of this 
chalk sea was highly charged with phosphatic matter derived 
first from original sources, as the deposits of Norway and 
Canada, then passing into seaweed, bones, shells horny and 
calcareous, and preponderating perhaps in the softer substance 
of the organisms themselves, and for a long time permeating 
all substances receptive of it, and gathering itself into various 
shapes around organic centres. 

Higher up in the series, see section fig. 34, at the summit 
of the chalk and just above the London clay, we find the bed 
of phosphatic nodules worked in Suffolk. The nodules of this 
bed seem to have been derived in part from the London clay, 
and are due also in part to the operation of the causes already 
referred to. These nodules are not so valuable in commerce 
as those from Cambridge, containing as they do less phosphate 
of lime, more iron, and being of greater hardness. It was, 
however, the recognition of the phosphatic nature of these 
nodules by Professor Henslow, who regarded them as the 
exuviae of extinct animals, that led to the discovering and 
working of the deposits already described. 

In working these deposits in the three counties of Bedford, 
Cambridge, and Suffolk, the contractor pays the owner of 
the soil from ioo/. to 140!. per acre. The average yield is 



PRODUCTION OF BRITISH PHOSPHORITES. 151 

about 300 tons per acre, and the value until recently of the 
nodules about 50^. per ton. When it is considered that the 
digger has to turnover from 3 to 15, sometimes 20 feet of 
overlying soil and sand, and to restore the land to its original 
condition, that he has also to wash, sort, and convey the 
nodules to a railway, it will be plain that the price paid to the 
landowner is too much, and that in the face of phosphates 
more cheaply won abroad, English phosphate-digging can 
hardly be profitably carried on. The fact, as shown by tables 
given further on, is that this branch of English industry has 
declined during the last seven years, and must finally die out 
if the present low prices prevail and such exorbitant royalty 
dues are charged. This will be especially true when the out- 
crop of these beds is exhausted and the nodules, if won at 
all, will have to be followed in depth by mining. The outcrop 
of the Greensand and Gault strata may be followed south- 
ward to Folkestone, and they contain more or less nodular 
phosphatic matter all along their course. On the other side 
of the Channel, around Boulogne, they have yielded a con- 
siderable quantity of low-percentaged phosphate of lime to 
commerce. 

The production of the three counties of Cambridge, Bed- 
ford, and Suffolk, for the seven years named, is estimated as 
follows in the Mineral Statistics of the United Kingdom, edited 
by Mr. Robert Hunt, F.R.S. 

Tons. Value. 

1875 . . 250,000 . . ^62 7,000 

1876 ,. . 258,000 . . 625,000 

1877 . . 69,000 . ' 200,000 

1878 ..- . 54,000 . 150,000 

1879 .'..> . 34,000 . . 73,750 

1880 . . 30,000 . . 7o>95o 

1881 . . 31,500 . . 86,628 



152 EARTHY AND OTHER MINERALS. 

PHOSPHATIC DEPOSITS OF THE ARDENNES AND THE 
MEUSE, FRANCE AND BELGIUM } 

Phosphates have been worked regularly in the Ardennes 
since their discovery in 1852 to 1855 by Messrs, de Molon, 
Thurneisen, Rosseau, and Dessailly. 

The discovery soon passed from the limits of the Ardennes 
into the department of the Meuse, where 1,000 tons were raised 
in 1862, 11,000 tons in 1867, and at the present time the 
production is estimated at over 40,000 tons a year. 

The strata of the region are divided in ascending order into 
the Greensand, the Gault, and the Tufaceous chalk or Gaize. 
A comparison of this description with the section fig. 34, 
show that these deposits correspond to those in the same strata 
in England. In the Ardennes the Greensand beds repose 
sometimes upon the Kimmeridge clay, and sometimes upon 
beds of older Jurassic agejthan this. In the arrondissement of 
Vouziers they rest upon the Kimmeridge clay, and they are 
developed in great strength in the communes of Grand Pre, 
Marcy, Cheviers, Sommerance, Fleville, Cernay, Chatel, Apre- 
mont, and Exermont. The formation extends in isolated 
patches to the north-east of these localities in the communes 
of Livry de Fosse, Remonville, Andevarmen, and Barricourt, 
where it is found resting upon the Astarte bed, a bed lower 
down in the series than the Kimmeridge clay. It is also 
found, but of less thickness, in the valley that descends to 
Quatre Champs and Vouziers, and in the communes of Ternon 
and Voncy it rests immediately upon the Astarte bed. It 
advances in very fine beds upon the coral rag of Saulces, 
Faissault, Puisseux, and Norron. To the west of this last com- 
mune it is reduced to nothing. It rests upon the Oxford clay 
and upon the inferior or lower Jurassic beds in the communes 
of Neuf, Maison, Aubigny, Logny, Bogny, and to the north 
upon the plateaux of Rumigny and the neighbouring com- 
munes. It will thus be seen that the Greensand beds rest in 
1 Ed. Nivot, Notice sur Us Gisements et V Exploration des Phosphat 
de Chaux Fossiles dans le Departement de la Meuse. Bull. Ac. Royal, 
Belgium, second series, t. xxx. xl., 25 40. 



PHOSPHORITE DEPOSITS OF BELGIUM. 153 

depressions of the Jurassic strata in which the latter have been 
more or less worn away. 

In the Meuse the Green sand beds extend parallel to the 
two banks of the Oise, a tributary of the river Aisne, from 
Montblainville on the northern limit of the department to 
Clermont in Argonne. In all this region they repose upon the 
Portland limestone that forms the solid rock of the valley. 

The total thickness of the Greensand in the Ardennes and 
the Meuse is from 90 to 140 feet. The superficial area 
covered by these beds is estimated at 36,800 hectares. 

In the School of Mines at Paris there are samples from all 
the points worked within this area. The phosphate beds 
occupy two distinct levels, one in the Greensands and one in 
the overlying Gault. The first of these beds, or group of beds, 
is encased in ochrey and greenish sands which range from 9 to 
1 6 yards in thickness. This whole deposit is formed of fine- 
grained sands and clays, which are mixed more or less with a 
great quantity of silicate of iron. The general composition is 
silica 52-00, protoxide of iron 28-00, with 7*00 to 8'oo of 
alumina, and the same proportion of magnesia. 

There are two groups of phosphatic nodules contained in 
these beds. The first group is composed of white and grey 
nodules of the shape of nipples. They range in size from that 
of a walnut to that of a fist. They are very compact and of a 
metallic lustre. The interior is formed of an agglomeration of 
little grains of green chlorite in a phosphatic cement, a certain 
number also appearing in the encasing rock. The other group 
consists of black or dark green nodules often cemented together 
and penetrated around the outside with grains of the enclosing 
rock, and with crystals of iron pyrites or of gypsum. They 
are also mixed with iron pyrites and are impressed with casts 
of shells and of serpulae, with traces also of coraline forms. 
The structure of the nodules of this group is more compact 
than that of the first. They are richer also in phosphatic 
matter, containing 55 to 60 per cent., while those of the first 
group only contain 40 to 45. In this respect, therefore, it 
will be seen that they resemble the two groups of the phos- 



154 EARTHY AND OTHER MINERALS. 

phatic nodules of similar beds in Russia, as described on 
page 158, except that these two classes of nodules occur in the 
same bed. The thickness of the bed is usually from 6 to 8 
inches, sometimes not more than from 2 to 4 inches. It differs 
a little in its exact place in the Greensand, being sometimes 
quite at the base and sometimes a little higher up in the series. 
The extraction is by open workings of a usual depth of 6 to 7 
feet. At Jardinet, west of Varennes, the workings extend to a 
depth of 15 to 20 feet. The nodules receive from the workmen 
the not over polite name of ' dung of the devil and his rogues.' 

The Gault lies upon the Greensand, and is about 50 feet in 
thickness. It is composed of green and greyish green clays, 
sometimes brown, dark brown, and nearly black. These clays 
are plastic, and are used for the manufacture of tiles and 
pottery. They are sandy at their base, and pass gradually 
upwards into clay ; balls of iron pyrites are scattered throughout 
them. Phosphatic nodules are also disseminated through the 
mass. These consist of corals and sponges, and the phosphatic 
shells common in the lower bed. A great number of these 
shells are ammonites and hamites, with some gasteropoda and 
lamellibranchiate shells. There are also teeth of fish, and 
fossil wood. These nodules are as rich in phosphoric acid 
as are the dark-coloured nodules of the bed in the Greensand. 

Above the Gault is the deposit locally known as La Gaize. 
This occupies the place of our Upper Greensand. It is here 
a lenticular deposit intercalated between the Gault and the 
chalk marls. It forms a chain of escarpments about 900 feet 
high, which follows the left bank of the Oise. It is a tender 
and porous rock of a whitish yellow colour, passing in its lower 
part to a grey rock much more clayey than the upper part. 

The phosphatic nodules lie about 15 yards above the clay of 
the Gault. They are known as ' nodules de Gaize ' or ' coquins 
de Gaize.' They range from a dark grey to black in colour, 
and have a polished surface. Their interior is formed of greyish 
matter, in appearance like the surrounding rock. The nodules 
are similar to those of tke Gault just described, and the fossils 
are nearly identical. 



PHOSPHATIC DEPOSITS OF SOUTH OF FRANCE. 155 

The nodules of the Ardennes and the Meuse yield a 
maximum of 25 per cent, of phosphoric acid, equal to 55 of 
phosphate of lime. In general composition they are similar 
to those from our Bedford and Cambridge deposits. Probably 
they contain more iron and alumina, and from their inland 
position can hardly be exported successfully. 

PHOSPHATIC DEPOSITS OF BELLEGARDE, LA PORTE 

DU RHONE. 

These deposits of the south of France are of similar character 
to those just described. They were referred to by Brogniart 
in 1822, and by various writers up to Risler in 1872. They 
occur in the environs of Bellegarde, Lanorans and Mussel 
being the principal localities where works have been carried 
on. The deposit worked answers stratigraphically to the base 
of the Gault and the phosphatic matters contained in fossils and 
their fragments, some of which have a rolled appearance. 
There are few if any nodules of a coprolite appearance. The 
proportion of phosphatic fossils to the entire mass is about 
one-fifth, and experiments show the following results with 
regard to the fossils named. 

Phosphate Carbonate 
of Lime. of Lime. 

Ammonite 46-20 22-80 

Inocerame . ..-,,-.. . 38-25 33'5S 

Gryphea 52-00 2 4' 2 S 

Nautili . . . . . 65-30^ 29-60 

Dr. Voelcker gives the following analysis of a sample of 
Bellegarde phosphate, and he states that the sample was lighter 
in colour than the Cambridge nodules and was softer, and so 
more easily ground to powder. 

Moisture and water of combination . . 2-79 

* Phosphoric acid 25-10 

Lime 40- 1 1 

Oxide of iron and alumina ) 

Fluorine . . . / ' ' ' ^'^ 
Insoluble silicious matter . . . .17-62 

100-00 

* Equal to 54-79 per cent, of phosphate of lime. 



156 EARTHY AND OTHER MINERALS. 

Deposits of similar age to those last described are also 
worked between Montpellier and Avignon. The order of the 
strata, in descending order, is : 

1. Diluvium. 

2. Marls and sands, with occasional nodules of phosphate reaching 

to a thickness of 80 yards. 

3. Sandy clay, Gault proper, from 7 to 8 yards thick, with green grains 

of glauconite. This is sub-divided into 

(a] Bank superior, yellowish gray clay, about 2 ft. 9 in. 

thick. 

(b] Middle, bluish green clay, about 2 ft. thick, divided from 

the next below by 6 ft. 6 in. of green sandy marl. 

(c] Inferior, composed almost entirely of friable shells among 

a green clayey sand. Base of Gault. 

4. Aphen, superior, 6 yards j Greensand 

5. ,, inferior, 16 ) 

6. Phosphatic nodules. 

In this bed the phosphatic matter is concentrated in the 
debris of fossils. The bed is largely made up of fossils, mostly 
in a rolled form ; but many shells are found in a perfect state 
of preservation, and they assimilate in their general character to 
those of the Gault. There are few, if any, of the rolled, shape- 
less nodules, designated in England as coprolites. It is 
interesting to notice the proportion of phosphate and carbonate 
of lime contained in each of the principal shells. 

The general colour is lighter than that of the Bedford and 
Cambridge deposits, and the quality is higher than that of 
those deposits, and also those of the Ardennes. Dr. Voelcker 
gives the two following analyses : 

No. i. No. 2. 

Moisture and water of combination . 2-79 2-95 

* Phosphoric acid .... 25-10 27-76 

Lime 40-11 41-88 

Oxide of iron and alumina . . \ 14-78 i -c6 

Fluorine J 3 

t Carbonic acid .... 7-10 

Insoluble silicious matter . . . 17-62 9-75 

100-00 100-00 

* Equal to tribasic phosphate of lime 54- 79 60-60 
f Equal to carbonate of lime . . 16-14 



PHOSPHATIC DEPOSITS OF RUSSIA. 157 

PHOSPHATIC DEPOSITS OF THE CRETACEOUS STRATA 
OF RUSSIA. 

In the Journal d' Agriculture Pratique of the year 1872 
M. Yermelow drew attention to the rich deposits of phosphate 
of lime existing in the cretaceous rocks of Russia. 

The deposits extend between the rivers Desna and Don, and 
they traverse the governments of Smolensk, Orel, Koursk, and 
Voronife, presenting a level line of length of about 100 miles. 
Along this line a vast quantity of phosphate of lime is estimated 
as available for working. 

The discovery of these Russian deposits of the mineral, as 
far as their application to agriculture is concerned, dates from 
the year 1858. In the earlier part of the present century 
geologists, among whom was the late Sir Roderick Murchison, 
had noticed in the neighbourhood of the towns of Koursk and 
Voronife blackish stones, which they took to be ironstones. 
These stones, known by the popular name of samorod black- 
stone or hornstone had been worked from time immemorial, 
for the construction and repairs of streets and roads. 

In the year 1850 M. Kiprianow, a Russian engineer, who 
had used the stones for this purpose, gave an account of his 
observations in the Gazette de Koursk, in which he spoke of the 
mineral as iron. He at the same time sent to various learned 
men samples taken from the deposits. 

In 1858, as the result of the analyses and researches of 
M. Khodnew, Professor of Chemistry at St. Petersburg, it was 
ascertained that the samorod was largely composed of phos- 
phate of lime, and in different places of varying proportions of 
carbonate of lime, oxide of iron, and alumina, all of which 
were mixed with the clay and sand that constituted the rock. 

In 1 86 1 M. V. Solsky, in the Revue Agricole, contributed 
a series of articles on the agricultural value of the deposits, 
while MM. Glaus and Guilemin had, by their researches and 
analyses, arrived at similar conclusions. 

In 1866 Professor Engelhardt, of St. Petersburg, accom- 
panied by M. Yermelow, received the official mission of ex- 



158 EARTHY AND OTHER MINERALS. 

ploring the deposits, and from their reports we gather that the 
deposits lie under the white chalk, and are continued down 
into the greensands and sandstone below, the general descend- 
ing order being : 

1. Soil. 

2. Diluvial beds. 

3. Clayey marl of a varying thickness. 

4. White chalk. 

5. Sandy marl, with phosphatic nodules scattered throughout 
the mass. 

6. Greensands, in which are one or more beds of phosphate 
of lime from 6 to 1 2 inches thick, in the form of nodules and 
concretions, which are often cemented together. 

The number of beds ranges from one to seven ; but of the 
higher number there is seldom more than two of importance, 
the rest being simply strings. The phosphatic nodules of the 
beds are intermixed with grey, brown, and yellow sands. The 
depth of the beds from the surface is very variable. Along its 
outcrop the nodules are mixed with the surface soil, while at 
a distance of a few hundred yards along its dip they are a 
good depth ; but as the strata rise again to the surface, forming 
a shallow trough or series of basins, the maximum depth is not 
very great. 

The general direction of the beds is from north-west to 
south-east, from Koursk to the little town of Koomy. In the 
north-west portion of this belt the chalk beds are much de- 
veloped, so that it is difficult to reach the deposits in depth. 
To the south-east the beds of the greensand prevail, and the 
deposits are more accessible. The encasing rock, whether of 
chalk or sand, both above and below the deposits, contain 
phosphatic matter, those below containing the largest propor- 
tion, and are most compact in their character. 

The character of the nodules is variable, each deposit or 
locality having its special features ; but these may be broadly 
divided into two very distinct groups. 

The first presents the form of nodules, round or kidney- 
shaped, of variable size, black, brown, grey, and green in 



ANALYSES OF RUSSIAN PHOSPHATES. 159 

colour. To this series belong the separate nodules, which are 
usually less rich. The second is an agglomeration of very 
large nodules cemented together into a sort of flag, which used 
to be quarried for road purposes. These nodules are richest 
when most dense, and of a deep black colour, the sandy, friable 
varieties being comparatively poor. The density, texture, and 
colour vary in different portions of the same beds. The 
cement enclosing the nodules is also phosphatic numbers 
of fossils and fragments of fossils, bones, shells, corals, sponges, 
and wood. These are taken as belonging to the age of green- 
sand, and they are richest in phosphoric acid 30 to 35 
per cent. 

In the governments of Tambow and Spaask the principal 
phosphate bed is covered by a bed of greensand, with grains of 
glauconite and nests of mica. We have seen how closely 
associated that last mineral is with the apatite of the older 
rocks of Canada and Norway. The following list will show 
the variations of the proportions of phosphatic matter in 
different parts of the area described : 

Phosphoric equaUo Phosphate 

Zormo 14-47 31-59 

Korennaya 17-90 38*78 

Yablonetz 22-07 47'8l 

Kotawetz . , . . . 27-24 59'Oi 

Koursk 14*25 30-08 

Nendowistche 16-11 35- 1 7 

Orlinoye Guesdo . " . . . 18-48 4'35 

The following analysis by Dr. Voelcker shows the general 
composition of the merchantable qualities of these phos- 
phates : 

Moisture and water of combination . ' .. . . 3-55 

Phosphoric acid 22-42 

Lime . . , . . . .- ". ' . 33*84 
Oxide of iron, alumina, fluorine, carbonic acid, &c. . 9-94 
Insoluble silicious matier . . ., 30*25 

lOO'OO 

These deposits occupy the same geological horizon as those ot 
Bedford and Cambridge. 



i6o 



CHAPTER X. 

PHOSPHATE OF LIME continued. 

Phosphate of Lime in Tertiary Strata Phosphatic Deposits of Nassau, 
North Germany Situation Geological Structure of the District 
Illustrations of Modes of Occurrence Whence derived Analyses 
Phosphates of Tarn-et- Garonne, France Growth of the Industry 
Geological Position Modes of Occurrence Similarity to the German 
Deposits Analyses Phosphatic Deposits of Carolina, America 
History of the Discovery of Geological Position Characteristics 
Land and, River Phosphates Analyses Recent Phosphates Alta 
Vela Aruba Island Navassa Island Pedro Keys Redonda Island 
Sombrero Island St. Martin's Island. 

THE PHOSPHORITE DEPOSITS OF NASSAU, NORTH 
GERMANY} 

IN the year 1850 M. F. Sandberger had distinguished the 
phosphate of the neighbourhood of Diez as a mineral of man- 
ganese. Later M. Meyer, in searching for manganese in the 
neighbourhood of Staffel, discovered a stony mineral which 
eventually proved to be phosphate of lime. The working of 
mines at Staffel for this mineral dates from 1863, and samples 
were shown at the Paris Exhibition. In July, 1864, Professor 
Fresenius and M. Moh, of Coblentz, made analyses of the 
mineral, the results of which led to the discovery and explora- 
tion of new beds and deposits, and the whole question attracted 
the attention of eminent English agricultual chemists and 
gentlemen engaged in the manufacture of chemical manures. 
In the summer of 1867 I was engaged in the examination 

1 D. C. Davies on 'The Deposits of Phosphate of Lime recently dis- 
covered in Nassau, North Germany.' Geological Magazine, 1868, p. 262, 
et seq. 



o II 




8 "Sfi 



.s 



GEOLOGICAL STRUCTURE OF NASSAU, N. GERMANY. l6l 

of about fifty mines and mineral properties containing phos- 
phorite within the area to be described. ^ 
The general results of this examina- 
tion were published in the Geological 
Magazine of the following year. 

To the description contained in 
that communication I may now add 
some of the more practical details and 
results which were then confined to a 
private report. The principal phos- 
phorite deposits of Nassau occupy an. 
irregular area, bounded on the north- 
east by the town of Weilburg, on the 
north-west by the Westerwald, on the 
east by the Taunus Mountains, and on 
the south by the town of Dietz. South 
of this point, as well as to the north-east 
of Weilburg, there are traces of the 
occurrence of the deposits ; but from 
the nature of the underlying rock they 
are limited in extent. Inside of the 
eastern and southern boundaries of this 
district flows the river Lahn, which is 
made use of at various points along its 
course for the purpose of washing the 
mineral from the surrounding clay, as 
well as for the carriage of the washed 
material to the junction of this river 
with the Rhine at Oberlahnstein, about 
three miles above Coblentz. The sec- 
tion, fig. 36, will give a general idea 
of the geological structure of the dis- 
trict. 

The basement rock of the district 
(i) is porphyritic, varying in colour 
from dark to light grey and green ; the green is thickly 
studded with cavities containing softer felspathic and cal- 

M 



til. 



I 



162 



EARTHY AND OTHER MINERALS. 



careous matter, which, after long exposure to the atmosphere, 
disappears. 

Upon this rock, in its many cavities, rests a thick suc- 




FIG. 37. SECTION NEAR STAFFEL SHOWING PHOSPHORITE RESTING IN DISLOCATION 
OF THE LIMESTONE. 

i, Clay- 2, Phosphorite. 3 3, Limestone. 4, Line of Fault, i, Shaft. 

cession of slaty and shaly beds (2) Schiefer stein. These, as 
shown in an admirable section on the roadside south of Weil- 
burg, are often greatly twisted and contorted. They are 
probably the equivalent of the slaty beds worked at Wissen- 




FIG. 38. SECTION AT CUBACH, NASSAU, SHOWING PHOSPHORITE AND MANGANESE 
RESTING IN HOLLOWS OF THE LIMESTONE. 

i, Clay. 2, Phosphorite, 10 to 15 ft. thick. 3, Limestone, -f -+ +, Deposits of 
Manganese. 

bach to the north-west. These are overlaid by a great thick- 
ness of dark red sandstone beds (3) (Spirifer Sandstein, pro- 
bably), which in places contains and is overlaid by haematite 
deposits, which are largely worked. Over large portions of the 




FIG. 39. SECTION OF PHOSPHORITE NEAR ARFURT, 

NASSAU. 



i, Clayey gravel. 2, Stiff Cla; 
upon rounded and fretted 



<3, Phosphorite resting 
of Limestone (4). 



DESCRIPTION OF NASSAU PHOSPHATE DEPOSITS. 163 

district these rocks are capped by a great thickness of massive 
limestone (4), locally known as Dolomit, and being probably the 
equivalent of the Eifel limestone and of the limestones in our 
middle Devonian series the Ilfracombe slates and limestones. 
It is resting upon this, deposited in cracks and dislocations, 
fig. 37, and in water- 
worn hollows and 
abrasions, figs. 38 
and 39, that the phos- 
phatic deposit (5) is 
found, the whole 
series being crowned 
with a covering of 
brown clay (6) (Thon\ 
which sometimes as- 
sumes a shaly appear- 
ance, and which also, in its upper portion, occasionally con- 
tains numerous fragments of the adjacent rocks. 

The deposit occurs in the form of concretions embedded 
in a matrix of clay. These concretions are most irregular in 
shape, and they vary in size from that of an apple to great 
masses, conglomerations of concretions, weighing several tons. 
It would also seem as if some of the original concretions had 
subsequently to their formation been subjected to a good deal 
of attrition. This is indicated by the preponderance of small 
fragments, decreasing in size to that of grains of sand. Where 
the deposit assumes this form it is known locally as Washstein. 

Besides the phosphate of lime there are also deposits of 
haematite and manganese occurring with it in just the same 
position, and resting within the inequalities of the underlying 
limestone. As far as my observation went these deposits are 
found in bulk around the outer margin of the northern half of 
the phosphatic area, although there are some of considerable 
size in the more central portions of the district. It would 
also seem that some portions of these two minerals were held 
in suspension or solution by the water, and deposited along 
with phosphatic matter. They give the deep yellow and brown 



164 



EARTHY AND OTHER MINERALS. 



colours to some of the concretions, increase their hardness, 
and have so permeated the phosphatic matter in places as to 
considerably lessen its commercial value. 

Along the north-western and north-eastern boundaries of 
the area, where the deposits border on the development of the 
older rocks, we find the greatest admixture of these extraneous 
matters, and the percentage of phosphate of lime ranging below 
50 per cent.; but southward, on the great mass of limestone 
extending from south of Weilburg to Limburg, Staffel, and 
Dietz, the deposit improves in quality, is white and creamy in 
colour, and contains in places, as at Staffel, as much as 92 per 
cent, of phosphate of lime, when it yields some beautiful crys- 
talline forms of apatite. 

As might be expected from the mode of its occurrence, the 




FIG. 40. SECTION OF PHOSPHORITE WORKING IN OPHEIM, NEAR LIMBURG, NASSAU. 
i, Clay, 30 to 40 ft. thick. 2, Batch of pale-coloured phosphatic Concretions, varying 

trom 3 to 10 ft. in thickness, the Phosphate set in Clay and interspersed with a little 

Manganese. 3, Underlying Limestone. 

deposit is very irregular in thickness, varying in the same mine 
from 6 inches to 10 feet. Fig. 40 represents its appearance in 
a mine at Opheim, a little to the west of Limburg. Generally 
speaking it attains its greatest thickness on a line ranging 
north-east and south-west along the centre of the underlying 
limestone, and it thins out gradually to the north-west and 
south-east. To the north-west and west the brown clay also 
becomes thinner, and is found covered with a splintery gravel 
(Quartzgeschiebe), the detritus of the neighbouring rocks. 
Subject to local variations, the phosphatic deposit seems co- 
extensive with the area of the limestone, its presence or absence 
at particular points depending upon ist, whether there is a 



METHOD OF WORKING THE NASSAU DEPOSITS. 165 

ridge or depression, or series of depressions, in the limestone ; 
2nd, the presence in force of haematite and manganese de- 
posits ; and, 3rd, the possibility of its having suffered denuda- 
tion in exposed places since its deposition. 

The clay is from 10 to 100 feet thick, and the method of 
mining is, when the clay is thin, to strip it off and work the 
deposit in an open work, as at Cubach, fig. 38 ; when the clay 
is thick a number of small shafts, about 4 feet diameter, are 
put down and communicated with each other by following the 
deposit underground. If the clay is wet or sandy, these shafts 
are secured by wickerwork. They are worked by windlasses. 

The workings underground are most irregular, their direc- 
tion being dependent upon the presence or otherwise of the 
phosphate. At only one group of mines, ' Heckolshausen,' 
did I see any attempt at artificial ventilation, and there the 
workings were low and wet, and the air very bad. 

I have assumed at the head of this chapter that the de- 
posits are of Tertiary age, and I would place them among the 
oldest of the Tertiary deposits older than those of Tarn- 
et-Garonne, to which, in some respects, they bear great 
resemblance. 

To the inquiry, Whence came such an amount of phosphatic 
matter ? Several answers have been given. It has been sup- 
posed to have been derived from immense shoals of fish and 
other organisms which crowded the shallows of the limestone 
sea, and whose remains were deposited in the hollows and 
crevices of the rock. It has also been suggested that the 
phosphorite owes its origin to the emissions from below 
bringing up phosphoric acid ; and, further, that the phosphate 
was dissolved out of the porphyritic rocks, as well as out of the 
limestones, by the action of carbonic acid. Primarily we 
must, I think, call to our aid the influx from below of phos- 
phoric acid, aided, secondly, by the supplies derived from the 
dissolving of the older rocks. These two sources being com- 
patible with the idea that life would be abundant in a sea of 
the geologic age, this would be charged largely with phos- 
phatic matter, so that there was first of all an abundance of 



i66 



EARTHY AND OTHER MINERALS. 



this essential element of organic life. The growth and decay 
of organic life would, in its turn, help to increase the quantity 
of phosphatic matter. There are not, it is true, any distinct 
organic remains in the deposits ; but the structure and shape 
of these may have been obliterated by chemical action. 

The specific gravity of the different colours is as follows : 

Pale buff. Grey. Dark, hard. Dark. 

1-9 2-6 2-7 2-8 

the quality deteriorating with the density of colour. 
The following are some of the mineral analyses : 






Weinbach. 


Cubach 
and 
Edels- 
burg. 


Staffel. 


Grave- 
neck. 


Op- 
heim. 


Wil- 
mar. 


Phosphate of lime 
of iron 
and alumina . 
Sand and inso- 
luble matter 
Sulphate of lime . 


Se- 
lected. 
58-40 

10-00 


Gene- 
ral. 
54-00 

10-00 


53-30 
I7-20 

I4-70 

14-80 


Se- 
lected. 
92-OO 

3-00 
5-00 


Gene- 
ral. 
62-00 

18-00 

7-00 

12-00 


57-60 
10-40 
I5-20 

16-80 


65-10 
I3-00 
21-90 


52-70 

11-60 
35-70 


100-00 


100-00 


100-00 


100-00 


99-00 


100-00 


100-00 


100-00 



The following are more recent and more detailed analyses 
of the richer sorts by Dr. Voelcker, of specimens from the 
neighbourhood of Staffel : 






No. i. 


No. 2. 


No. 3. 


Water 


65 


25 


98 


* Phosphoric acid 


40-56 


38-12 


36T9 


Lime 


56-29 


53-92 


49*44 


Oxide of iron | 
Alumina j 


I-2I 


93 


( -96 

1 3'07 


Magnesia j 
Fluorine j 


97 


69) 
3-i6/ 


2-88 


fCarbonic acid 





2'75 


1-87 


Sulphuric acid 





09 




Silica 


32 


09 


4-61 




100-00 


100-00 


100-00 


* Equal to tribasic phosphate of lime 
t Equal to carbonate of lime 


88-54 


83-21 
6-25 


79-01 
4-25 



PHOSPHATES OF TARN-ET-GARONNE, FRANCE. 167 

The first table, however, represents more correctly the average 
quality of the Nassau phosphorite ; indeed, if we include the 
small stuff (washstein), the result is above the average. The 
cost of raising, dressing, and washing, with carriage to the 
river Lahn, amounts to 26s. to 30^. per English ton ; the 
freight to Oberlahnstein 31. to 4s. In order to send to England 
the mineral has to be reshipped on Rhine barges, and again 
reshipped upon seagoing craft. So that it will be seen that the 
German phosphates cannot be sent profitably to England, and, 
except with the higher qualities at the first, they have not. 
They are, however, largely manipulated at works established 
upon the Rhine. 



THE PHOSPHATES OF THE DEPARTMENT OF TARN- 
ET-GARONNE, FRANCE. 1 

The important phosphatic deposits of these departments in 
the South of France attracted attention towards the close of 
the Franco-German war. In the year 1871 M. Daubre, of the 
Ecole des Mines, visited and described them, and since then 
an important industry has sprung up. 

The phosphatic region is situated in the north-east of the 
department, on the right bank of the river Aveyron, in the 
neighbourhood of Montauban. The deposits occur on the 
summit of a great plateau which is interrupted by valleys of 
erosion. The basement rock of the country is Oolitic, princi- 
pally the divisions Oxford clay and Coralline rag. From 
underneath these strata, at some distance, rise the granite and 
gneiss of Aveyron, and the district is not far from a recent 
volcanic region. Upon the Oolitic strata rest Tertiary beds, 
which are clayey and sandy beds of the Eocene strata. 

Fig. 41 will shew the geological position of the phosphate 
bed with its contiguous strata. 

The surface clay is yellow, red, and brown. It is strongly 
coloured by the oxides of iron, and intercalated in it are beds 

1 'Phosphates de Tarn-et-Garonne,' par M. Lescure, Bulletin de la 
Societe Geologique de France, Third Series, torn. iii. 



i68 



EARTHY AND OTHER MINERALS. 



of pisolitic iron ore, which have been much worked. Near the 
surface there are embedded in the clay the bones of living 
species of animals, and lower down there are numerous bones 
of extinct species, carnivorous and herbivorous, all huddled 
together, and strongly cemented as a breccia in a reddish clay. 
The clay on the surface does not give any indications of the 
phosphatic deposits below, but these are sought for where there 
are hollows indicating abrasions or fractures in the underlying 
rock. 

The phosphate of lime is found in tubercular and kidney- 




FIG. 41. SECTION OF PHOSPHATIC AND ASSOCIATED STRATA, TARN-ET-GARONNE, 
FRANCE. 

i, Lower Miocene Marls and Sands. 2, Eocene Marls and Sands. 3, Phosphatic 
Deposits resting- on the Edges of Oolitic Strata (5). 4, Cracks and Fissures in Oolitic 
Strata charged with Concretions of Phosphate. 5, Coralline Limestone and Oxford 
Clay of the Oolitic Strata. 6, Liassic Strata. 

shaped concretions in the cracks in the underlying limestones, 
as shown in fig. 41. They are intercalated vertically in the cracks 
in clay of reddish-brown and yellow colours, and often, also, 
occurring as thread or ribbon-like masses. They are sometimes 
white in colour, more frequently grey, with a waxy lustre and an 
opal-like appearance. Dr. Voelcker 1 says that he has found 
the white and opal-like specimens most rich in phosphoric acid, 
those of a yellow or brown colour less so this being the 

1 'On the Chemical Composition of Phosphatic Minerals used for 
Agricultural Purposes,' Journal of the Royal Agricultural Society of 
England, Second Series, vol. xi. part 2. 



BORDEAUX PHOSPHATES. 169 

ordinary kind, while those of a dark brown colour are of 
.an inferior kind. In these respects, as well as in the 
mode of their occurrence, it is interesting to compare these 
deposits with those of the valley of the Lahn, in Nassau, 
Germany. 

The richest quarries or mines are those worked in the most 
vertical cracks, and those having a north-east and south-west 
direction. The quarry of Larnagol, in Lot, may be taken as an 
example of the rest of these mines. It is 35 kilometres north- 
north-east of Malperie, and is situated at a height of 360 metres 
on the summit of the plateau of Oxford clay. It is divided 
into three or four exploitations. It has a north-east and south- 
west direction ; at the south-west end the clefts and veins running 
north-north-west and south-south-east are richest. From this 
end a large quantity of phosphate has been extracted. The 
veins at the north-east end are, or were recently, followed 
profitably. 

The phosphatic concretions in these cracks have been 
supposed to owe their origin to geyserine ejections, also to 
infiltration of water charged with phosphatic matter derived 
from the bones in the overlying clay, and also to the same 
substance abounding in the lagunes of the Eocene sea. From 
the absence of organic remains, as well as of small particles of 
bony structure, we must, I think, attribute the origin of the 
deposit chiefly to causes linked with the first of these hypo- 
theses, and regard these deposits as the result of phosphatic 
matter deposited pure and simple on the rocky floor of an 
Eocene sea from water largely impregnated with it. The 
lagunes would form deposits of a different character, resembling 
those at the summit of the London clay that is, concretions 
around organic centres. 

The phosphates from these deposits are known in England 
commercially as Bordeaux phosphates, being shipped from that 
port. At first the percentage of phosphate of lime ranged as 
high as 70 to 74 per cent. ; subsequently it did not average 
more than 60 per cent. 

The three following analyses, each of which I have selected 



170 



EARTHY AND OTHER MINERALS. 



as the average of a considerable group given by Dr. Voelcker, 
will shew the composition of the mineral. 

High Medium 

Quality. Quality. 

3-01 J "64\ 

2-n 1-64) 

34-01 30-47 

46-77 44-69 



Moisture . . . . 
Water of combination . 
*Phosphoric acid . . 
Lime .... 

Oxide of iron, alumina, car- 
bonic acid, &c. . 
Insoluble silicious matter 



f Equal to tribasic phos- 
phate of lime 




100-00 



I7-43 



66-52 



Inferior 
Quality. 

6-81 
25-96 



21-63 
14-09 



THE PHOSPHATIC DEPOSITS OF CAROLINA, 

AMERICA? 

These deposits, so important from their extent and com- 
mercial value, seem to have been first noticed by Ramsay in 
1797, in the History of South Carolina, who spoke of them as 
remarkable discoveries of phosphate of lime. They again 
attracted attention in the year 1837. In November of that 
year, in a plain of rice about a mile from the river Ashley, in 
the parish of St. Andre, Mr. Holmes found a number of red 
nodules, very hard and covered with impressions of marine 
shells. These nodules were spread over the surface of the soil, 
and they were heaped up in places as so many stones, so as 
not to hinder the cultivation of the soil. Mr. Holmes having 
some knowledge of geology and palaeontology, the shells, 
bones, teeth, and corals mixed up with the stones attracted 
his attention, and many of them were added to his collection 
of fossils. He pursued his studies and researches until the 
year 1842, when Mr. Ruffin was charged by the legislature to 
make an inquiry upon South Carolina from a geological and 
agricultural point of view, that gentleman having succeeded for 
some years in fertilizing poor land in Virginia with marl con- 

1 Brylinski, ' Rapport sur les Phosphates des Chaux de la Caroline du 
Sud,' Societe Geologique de Normandie, tome ii., 1875. 



THE CAROLINA PHOSPHATE DEPOSITS. 171 

taining about 25 per cent, of phosphate of lime. It was felt 
that the same results were possible in Carolina, and the 
farmers were eager for all the beds of marl and calcareous 
earth that could be found. Mr. Ruffin examined the country 
with great care and found extensive beds of marl. From 
samples collected from different localities he found marls con- 
taining carbonate of lime ranging from 50 to 80 per cent. 

Nevertheless, the results obtained in Carolina from the 
application of these marls were not equal to those obtained in 
Virginia from poorer marls which were more easily attacked 
and dissolved by the liquid acids, while those of Carolina were 
so intimately mixed with silica, oxide of iron, phosphate of 
lime, and other substances. Upon calcining these Carolina 
marls, however, they were found to be more powerful ferti- 
lizers than those of Virginia. Among other samples the 
nodules found by Mr. Holmes were submitted to Mr. Ruffin, 
but not finding carbonate of lime in them to any extent, that 
gentleman regarded altogether as improper their employment 
as fertilizers. 

About the same period, Professor Shepard, with Messrs. 
Lawrence Smith and W. Harmer, studied the question of the 
employment of marl in agriculture, but they also failed to 
distinguish the Ashley nodules from ordinary marl. 

The experiments in marling went on, and searches for the 
material were made among other places on an old plantation 
near Charleston. In digging and proving the soil, at a depth 
of about two feet, a regular bed about one foot thick of rocky 
substances fixed in the clay was reached. These substances 
were covered with shells, and were evidently identical with the 
loose stones of the same character found spread over the plain. 

Under this bed lay a marl bed of a yellowish colour, and 
containing 61 per cent, of carbonate of lime, passing into a 
marl of a greenish colour, containing up to 71 per cent, of 
carbonate of lime. 

Mr. Holmes did not neglect the opportunity of studying 
and comparing the different rocks with those discovered by 
him, but without as yet arriving at any definite or useful results. 



172 EARTHY AND OTHER MINERALS. 

In 1848 a Mr. Tuomy paid some attention to the rock, and 
noticed especially the comparative absence of carbonate of lirne 
in the lower marls, which he attributed to a different chemical 
condition of the water in which it was deposited. 

In 1850, Mr. Holmes, in a paper read before the American 
Association for the advancement of Science, noticed the 
interesting character of the rock chiefly on account of the 
fossiliferous nature and of its foetid odour; he also noticed the 
disparity between the amount of carbonate of lime in the rock, 
2 per cent., and that of the underlying marl, 60 to 70 per cent. 

Up to the year 1867, or thirty years after attention had 
been drawn to these deposits, the true character of the rock re- 
mained unknown, so that in 1859 Colonel Hatch amassed a 
great collection of the bones of extinct animals for the purpose 
of making manure, being ignorant of the properties of this 
nodular rock. So also in 1867 Messrs. Dakes & Co., who 
had formed with Dr. St. Julien and D. C. Ebaugh a company 
for the manufacture of manure, imported phosphatic rock from 
Nevassa, whilst they had close at home a large available supply 
of the mineral. 

In 1867, Dr. St. Julien, having received from Dr. F. 
Glidding specimens of teeth and bones found in a plantation 
called 'The Elms,' belonging to Dr. Glidding's father, exa- 
mined them carefully and recognised their true character. He 
therefore began to collect for himself the nodules found on the 
banks of the river Ashley. He sent one of these nodules to 
Dr. N. O. Pratt for analysis. This contained 34 per cent, of 
phosphate of lime. A specimen belonging to Mr. Holmes was 
found to contain 60 per cent. Mr. Holmes, foreseeing the 
value of these nodules as fertilisers, went to Ashley ferry, and 
studied the rock in situ, with a view of ascertaining the thick- 
ness and extent of the bed, and the results of his visit in these 
respects was eminently satisfactory. At this juncture the 
attention of Messrs. Pratt and Holmes had been directed by a 
book of the late Professor Ansted's to the phosphatic deposits 
of Cambridge, and they were struck with the resemblance 
between the character of the two deposits, as well as the 



SECTION OF STRATA IN SOUTH CAROLINA. 173 

apparent geological age, although in this they were mistaken. 
Convinced they had an important source of profit, they formed 
a company in Philadelphia, called the Charleston Mining and 
Manufacturing Company, with a capital of four million francs. 
The following table shows in descending order the geo- 
logical position of these deposits, which is further illustrated by 
the sections, figs. 42 and 43. 



Cultivated soil. 

Man and living animals. 

Place of the glacial clays, sands, and 
gravels of Europe. 

Sands and fragments of shells . . . 

Rocks of phosphate, yellow and green- 
ish marl . , , , . , . 



Sands and 
shells . 



clays containing fossil 



Age. 



Post-Pliocene. 

Pliocene. The shells belong 
in a large proportion to 
existing species. 



The lowest of these beds, No. 4, should in ordinary course 
rest upon Miocene strata, but these are absent,, and it rests 



42. SECTION OF PHOSPHATIC DEPOSIT, SOUTH CAROLINA, 
LEVEL. 




IvEVEL. 

i, Eocene Marls. 2, Sand. 3, Phosphates. 4, Sand and Soil. 5, Salt.* 



directly, as shewn in the sections, figs. 42 and 43, upon 
Eocene strata. 

The organisms of the phosphatic bed consists of corals and 
coralline structures ; the teeth and bones of marine animals re- 
sembling alligators. Few, if any, remains of terrestrial animals 
are found in the rock itself, although they are found among 



174 



EARTHY AND OTHER MINERALS. 



the nodules strewn upon the surface. These marine organisms 
seem to have been deposited in the deeper portions of an 
otherwise shallow sea, which probably was fed by the waters of 
the Atlantic bringing and leaving the molluscan, zoophytic, 
and crustacean life that abounded in its shallow waters. 

The deposit is in hollows and pockets in the strata below, 
and varies in thickness from fifteen inches to three feet. The 
quantity of merchantable phosphate of lime contained in it is 
estimated at from 800 to 1,000 tons per acre. The deposit has 
been traced over an area of about 50 square miles, and it is not 
yet known how much greater its workable area may be. 




FIG. 43. SECTION OF THE PHOSPHATIC DEPOSIT ON THE BANKS OF THE ASHLEY 
RIVER, SOUTH CAROLINA. 

i, Eocene Marls. 2, Clayey Sand. 3, Phosphate Bed. 4, Surface Soil. 

The bed just described is known as the land phosphate, but 
on the banks and in the beds of the rivers are the river phos- 
phates of a similar character, and probably the same deposit 
as shewn in fig. 43. These also have been proved as extending 
over a large area, so that for extent and facilities for cheap 
working and transit these Carolina phosphates are unequalled 
by any other. The average quality, 53 to 54 per cent., is not 
high, but they are good workable phosphates. At the pre- 
sent time they form the chief source of our supply in this 
country, although the increasing demand for them in America 
is gradually effecting an increase in price which, if it progresses, 
will lead us to turn to the hitherto neglected sources of supply 



ANALYSES OF CAROLINA PHOSPHATES. 



175 



at home. The annual amount of Carolina phosphates imported 
into this country during the last ten years may be taken at 
170,000 tons, of the value of ,500,000. 

Dr. Voelcker gives the following analysis illustrative of the 
composition of the Carolina land phosphates : 





No.'i. 


No. 2. 


No. 3. 


No. 4. 


No. 5 . 


No. 6. 


No. 7. 


Moisture .... 
Water of combination 
* Phosphoric acid . 
Lime 


J7'40 
26-50 

37'2O 


2-29 

24-29 
^8-71 


I0'30 

22-06 
37-24 


3-98 

25H7 
3O' 1 1 


8-01 

23-93 
36-71; 


(6-59 
I r '09 
24-80 
38-14 


7 -6 9 

i-34 
23-35 
36-41 


Oxide of iron, alu- 
mina, magnesia, 
carbonic acid, &c. 
Insoluble silicious 
matter .... 


I6-27 
12-63 


I7-28 
17-43 


I5 ! 45 
I4-95 


I8-82 
II-62 


16-88 
H'43 


17-01 
11-67 


16-54 
14-67 




100-00 


100-00 


100-00 


100-00 


100-00 


100-00 


100-00 


* Equal to tribasic 
phosphate of lime. 


57-85 


53-02 


48-16 


55-60 


52-24 


54-14 


50-98 



A full analysis by Dr. Charles H. Shepherd of Charleston, 
is also given below. 

ANALYSIS OF GROUND LAND-ROCK PHOSPHATES MADE BY DR. 

CHARLES H. SHEPHERD, JUN., CHARLESTON, SOUTH CAROLINA, 

MARCH 22ND, 1879. 

Moisture . . * . .- . 0-48 

Organic matter . . ' . - . . 4*30 

* Carbonic acid 3-63 

Sulphuric acid . . . . . . 2-18 

f Phosphoric acid .27-24 

Lime 42-68 

Magnesia 0-57 

Sesquioxide of iron ..... 3-80 

Alumina i'io 

Sand and insoluble silicious matter . . 13- 17 

Undetermined matter . . . . 0-88 



* Equivalent in carbonate of lime . 
f ,, ,, bone phosphate of lime 



176 EARTHY AND OTHER MINERALS. 

The reader interested in the working of English and Welsh 
phosphates may compare the above particulars, particularly the 
amounts of oxide of iron, alumina, magnesia, and carbonic acid, 
with the later analysis from bulk of the Welsh Silurian phos- 
phorite given in Chapter VIII. 

I have thus noticed the principal deposits of this mineral as 
they are found in the Laurentian, Silurian, Cretaceous, and 
Tertiary strata, and it only remains now for me to refer briefly 
to those apparently very recent deposits which are found on 
and surrounding the coralline islands of tropical seas. 1 

Alta Vela. This is a small island near St. Domingo, from 
which phosphate of lime containing a good deal of alumina is 
obtained. Some samples do not show more than 43 to 44 per 
cent, of phosphate of lime. An intermediate sample tested by 
Dr. Voelcker gave the following result : 

Moisture . . . . . . . } 

Water of combination . . , . . ) " 
* Phosphoric acid . .... . 26-33 

Oxide of iron 7-23 

Alumina 20-22 

Insoluble siliceous matter . . . .26-92 



100-00 
* Equal to tribasic acid . . . .57-26 

Owing to the absence of lime and the presence in such 
large quantities of oxide of iron, alumina, and insoluble silicious 
matter, this phosphate, with that of Redonda, is not adapted to 
the manufacture of superphosphates. It is, however, used in 
chemical works for the production of alum, in the manufacture 
of which it yields an impure phosphoric acid which with salts 
of ammonia and other fertilisers may be worked up into 
cherrn'cal manures. 

Aruba Island. This is one of the Leeward Islands of the 
Caribbean Sea. It is situated in 12 36' N. latitude and 70 8' 

1 Dr. Voelcker, ' On the Chemical Composition of Phosphatic Minerals 
used for Agricultural Purposes,' Journal of the Royal Agricultural 
Society, No. xxii., part ii. This paper contains very numerous analyses of 
different kinds of phosphates. 



PHOSPHATES OF ARUBA AND NAVASSA ISLANDS. 177 

W. longitude. The island also contains gold, which has been 
worked more or less since the year 1824. The phosphate is a 
hard rock-like mineral from yellow to light brown in colour, 
with dark brown spots and bands, veins of calc spar. The 
quality ranges from 60 to 75 per cent, an average sample 
showing the following result : 

Moisture and water of combination . . 5-54 

* Phosphoric acid 2 8'95 

Lime 30-18 

f Carbonic acid '98 

Oxide of iron 9*26 

Alumina, &c 17-22 

Insoluble silicious matter . . . . 7-87 



loo-oo 

* Equal to tribasic phosphate of lime . . 63-20 
f Equal to carbonate of lime . . . 2-23 

Navassa Island is a small uninhabited island of the 
Caribbean Sea. It is situated in 18 25' N. latitude and 75 5'W. 
longitude. It is surrounded by coral reefs, the coral rock 
forming the framework, the cavities of which are filled with 
phosphatic matter of a reddish brown colour. This is made up 
of globular grains of phosphate of lime which are cemented 
together in hard masses. The phosphate varies in quality, but 
the following may be regarded as the composition of an average 
sample. 

Moisture . -\ . ..,.., 8-50 
Water of combination . , . . 4-15 
* Phosphoric acid . . . . . 28-47 

Lime . . . . . . . 34*07 

Magnesia . .. . ' , . . *45 

t Carbonic acid . .. r'V ? 2 '3 
Oxide of iron / , . . . . 4-49 

Alumina ...,,. 9'4^ 

Sulphuric acid i'8i 

Insoluble silicious matter . . .6-28 



lOO'OO 

* Equal to tribasic phosphate of lime . 62-15 
f Equal to carbonate of lime . . . 5-22 

N 



178 EARTHY AND OTHER MINERALS. 

Pedro Keys, a small island south of Jamaica, also yields 
the mineral, showing 60 to 65 per cent, of tribasic phosphate 
of lime, but mixed with 20 per cent, of oxide of iron, alumina, 
magnesia, and carbonic acid, the three first being the elements 
which lower the value of the mineral. 

Redonda Island, situated 16 54' N., 62 21' W., is noted 
for the production of a phosphate of alumina which contains a 
good deal of oxide of iron and little or no lime, and can only 
be used for the same purposes as the Alta Vela phosphate 
already described. By a patent taken out by Messrs. Forbes 
and Price it was also intended to be used in the purification of 
town sewage. 

An analysis by Dr. Voelcker shows the following compo- 
sition : 

Moisture and water of combination . . . 21-15 

*Phosphoric acid 37'4 

Alumina and oxide of iron . . . . 32-26 
Insoluble silicious matter 9-55 

100-00 
* Corresponding to tribasic phosphate of lime . 80-86 

Sombrero Island, one of the Leeward Islands, situated 
about 60 miles east of the Danish West Indian Islands, is one 
of the oldest sources of phosphate of lime in this region. The 
mineral is a light-coloured, nearly white substance, very light 
and porous, consisting of shells and other marine organisms 
of living species set in a coralline framework. The mineral 
has now to be obtained from below the water-line, and it must 
be difficult to work it profitably. 

The following may be taken as its average composition : 

Moisture and water of combination . 8-92 

* Phosphoric acid . . . . 31-73 

Lime 45'69 

f Carbonic acid 5-99 

Oxide of iron and alumina . . . 7-07 

Insoluble silicious matter . -60 



100-00 

* Equal to tribasic phosphate of lime . 69-27 
f Equal to carbonate of lime . . 13-61 



PHOSPHATES OF ST. MARTIN'S ISLAND, ETC. 179 

This is a very valuable mineral phosphate, and it is to be 
hoped that upon exploration other islands of the numerous 
groups to which those already enumerated belong, will be 
found to contain phosphate of similar quality. 

St. Martin's Island is a small island belonging to the 
Windward Islands. It is situated in latitude 18 5' N., and in 
longitude 63 4' W. The phosphate from this island consists, 
like the Sombrero and Navassa, of phosphatic matter filling up 
a coralline framework. Its composition is variable, and great 
care has to be exercised in separating the richer quality from 
the usual minerals associated with it. 

The percentage of phosphate of lime ranges from 37 to 81, 
of carbonate of lime from 6 to 47, and of oxide of iron and 
alumina from 1-14 to n'97- 

Doubtless the mineral will be found on many others of the 
neighbouring islands. 

In reading the foregoing description of the phosphatic 
deposits of the world, it will be noticed how the earliest deposits 
in the Laurentian rocks of Canada and Norway are free from 
all traces of organic life, and how in all the succeeding deposits 
from the Silurian upwards, except in those of Estramadura and 
Nassau, organic remains are largely associated with the deposits 
and indeed form a part of them. This difference points to a 
difference in the original mode of deposition. In the first case 
the phosphatic matter was deposited pure and simple primarily 
on an ocean floor; and in the second case it had passed 
through organic forms and life before it found its place as a 
phosphate bed. 

It is also interesting to notice that just as in the case of 
chloride of sodium a certain group of minerals clustered 
around it and became associated with it in its deposits, so 
with phosphorite another group iron, titanium, manganese, and 
sulphur are associated with it throughout all time, and how in 
its turn phosphorus is intimately blended, although in a less 
degree, with most of our iron ores as it now seems to their 
deterioration. 

Practically, too, it will be seen that phosphate mining in 



180 EARTHY AND OTHER MINERALS. 

beds in the Secondary and Tertiary strata is a more certain 
and reliable operation, even where the mineral is only of ordi- 
nary strength, to apatite mining in the older rocks, where it 
occurs in strings, veins, and pockets, albeit of very high 
strength. 



PART III. 

CARBON, COMPOUNDS OF CARBON, 
AND SULPHUR. 



(EACH MINERAL CONSTITUTING A CLASS BY ITSELF, 
FORMING CLASS IV. AND CLASS V. OF THE LIST 
IN THE CONCLUDING CHAPTER.) 



83 



CHAPTER XI. 

CARBON AND CARBONACEOUS SUBSTANCES. 

The Diamond History of Attempts to consume it, by Boordt, Boyle, 
Cosmo III., Sir Isaac Newton, Sir George Mackenzie, and Sir 
Humphrey Davy Diamonds of India, of Brazil, of South Africa 
History of the Discovery and Progress of the Industry and Particulars 
of Mining Notable Diamonds Plumbago or Graphite of Borrow- 
dale, of Ayrshire, of North Wales, of Ceylon Particulars of Produc- 
tion in Ceylon Graphite in America Uses for which it is employed 
Jet Origin, of Name Jet Industry of Yorkshire. 

THE DIAMOND, AND DIAMOND MINING. 

THE diamond is pure carbon, and in this form is white and 
colourless. It is also tinged yellow, green, red, orange, brown, 
and black, when other minerals are present in it in minute 
quantities. It crystallises in several forms, some of them 






FIGS. 44, 45, 46, and 47. USUAL FORMS OF DIAMONDS. 

complex. Figs. 44, 45, 46, 47, show the ordinary shapes of 
diamonds. 

It is transparent when pure, and has an adamantine lustre, 
but the darker kinds are opaque. H. 10, gravity =3 '48 to 3*51. 

Diamonds are known by their great hardness. Except in the 
instance I have given, where boron was obtained in a degree 
of hardness that would scratch a diamond, it is the hardest of 



1 84 EARTHY AND OTHER MINERALS. 

all known substances. It was long considered to be incom- 
bustible, but in 1607 Boetius de Boordt suggested that it 
was inflammable. In 1673 Boyle proved that when it is 
exposed to a great heat it is dissipated into vapour. In 1694 
Boyle's experiments were confirmed by those of Cosmo III., 
Grand Duke of Tuscany, with his celebrated burning-glass. 
About the same date Sir Isaac Newton, from its great re- 
fractive power, described it as an unctuous substance coagu- 
lated. Lavoisier proved it to be composed of carbon by throw- 
ing the sun's rays, concentrated by a powerful lens, upon a 
diamond enclosed in a vessel with oxygen gas. The diamond 
and the oxygen disappeared, and carbonic acid was generated. 
This experiment was repeated by Sir George Mackenzie in 
the year 1800. In 1814 the experiment of the Grand Duke 
Cosmo was repeated, with similar results, by Sir Humphrey 
Davy, in Florence. 

Thus the hardest of all known bodies has been made to 
dissolve in the sun, and to pass away in a noxious vapour. 

It is thought that the carbon of the diamond is of vegetable 
origin, having been dissolved and redeposited in some such 
way as those referred to in connection with the rarer redeposited 
forms of silica and alumina. 

Diamonds were for a long time obtained almost exclusively 
from the East. 

In India they have been found in the district of Golconda, 
near the Pass of Bezoara, on the northern bank of the Kistno, 
about fifty miles from the sea. The river passes through the 
hills by a narrow gorge, which in course of time it had cut for 
itself through the rocks. In doing this an extensive ancient 
lake beyond has been emptied, and it is in the drift once lying 
at the bottom of the lake, and derived from the wearing 
down of the neighbouring ancient rocks, that diamonds have 
been found. In digging through this drift there is first about 
eighteen, inches of gravel, sand, and loam. Below this there is 
about four feet of mud and clay, and underneath this is the 
diamond deposit, three to four feet thick. It consists of a 
large number of rounded stones, and of gravel, cemented 



DIAMOND DEPOSITS OF INDIA AND BRAZIL, 185 

together in clay. Occasionally a thin layer of calcareous tufa 
occurs between this deposit and the overlying black mud. 
The natives were used to sink a pit a few feet diameter down 
to this deposit, and from the bottom to burrow in various 
directions as they best could. If unsuccessful, they speedily 
removed to another spot. From all accounts they seem to 
have made but a poor living at the work. 

Another locality in India is on the left bank of the Mus- 
nuddy river, near its junction with the Mahanuddy. Here 
diamonds were found in a kind of ferruginous conglomerate, 
and this appears to be the nearest approach to finding diamonds 
in the solid rock. After all this deposit was a driftal one, like 
that to be described as occurring in Brazil, only it had been 
hardened by the presence of iron in its cementing matter. 

Near Banaganpilly, 78 4' longitude, 15 4' latitude, diamonds 
have been found in a similar breccia, containing also horn- 
stone, chalcedony, jasper, yellow and red quartz. This breccia 
passes into a conglomerate of pudding-stone, composed of 
round pieces of quartz cemented by a calcareous clay or mud. 
The strata of the nearest mountains consist of slaty rock of 
all kinds, with quartz rock, sandstones, flint and hornstone, 
pure limestone proper, and tufaceous limestone. 

Diamonds are found in Borneo, on the west side of the 
Ratoos Mountains, associated with gold and platinum. 

From the year 1728, when they were first discovered, 
until within the last twenty years, a prolific source of diamonds 
was the neighbourhood of Tejuco, on the district of Serro de 
Frio, or Cold Mountains, to the north of Rio Janeiro, in the 
province of Minas Geraes, Brazil. 

The strata of the district consist of grits alternating 
with micaceous slate, with great masses of a kind of conglo- 
merate or pudding-stone composed of grit and rounded quartz. 
In the lower lands along the river courses there is a finer 
conglomerate consisting of the same materials with fragments 
of hornblende and granite, all partly cemented together with 
oxide of iron. This is called Cascalho^ and in it the diamonds 
occur, associated with garnets, topazes, and other precious 



1 86 EARTHY AND OTHER MINERALS. 

stones, and gold. The streams are diverted so that the cascalho of 
the river bed may be excavated and washed, the water being 
removed out of the deeper parts by rude machinery, and in 
some places the cascalho is hoisted up by the same means. 
The deposit is then carefully washed by negroes in a series of 
troughs, the operation being also carefully watched by overseers 
who sit upon high seats that have no backs, in order to prevent 
the overseers from sleeping. Formerly when a negro found 
a diamond weighing 17!- carats he received his liberty, amid 
much ceremony. As much cascalho is excavated and stored 
during the dry season as is supposed to be sufficient to employ 
the negroes in washing during the months when rain is more 
plentiful. It is also found in practice that whether the diamonds 
be large or small, about the same weight or number of carats 
is found in each cubic yard of the cascalho. As a matter of 
course, there^ is a very large proportion of minute diamonds 
obtained. These are ground and used for polishing the larger 
ones. The average cost to the Government per carat of the 
diamonds found is said to be 33^. The principal deposits and 
workings are along the banks of the Jequitinhona River. From 
1730 to 1814 the supply of diamonds from Brazil was esti- 
mated at 36,000 carats a year. In the year 1840 the yield 
was given at 20,000 carats. More recently the supply has been 
stated at from 25,000 to 30,000 carats yearly. At first it was 
difficult to sell diamonds obtained from Brazil, and the ex- 
pedient had to be resorted to of sending them first to India, 
to be from thence sent to Europe as Indian diamonds. 

Diamonds were discovered in the Ural Mountains of Russia, 
in the year 1829, by Humboldt and Rose, when travelling to 
Siberia. 

SOUTH AFRICAN DIAMONDS. 

The diamond fields of South Africa are situated mainly in 
Griqualand, about 700 miles north-east from Table Bay, and 
450 miles inland from Port Elizabeth and Natal on the east 
coast. Kimberley is the centre of the principal mining 
field, and the chief mines near it are Kimberley, De Beers, 



DIAMOND MINES OF SOUTH AFRICA. 1 87 

Du Toit's Pan, and Bultfontein. There are also two mines, 
Jagersfontein and Koffeyfontein, in the Orange Free State. 

The discovery of diamonds was made in the year 1867 by 
Mr. O'Riley, a trader and hunter, while on a visit to a colonist 
named Van Niekirk. 

The announcement of the discovery was at first received 
with great suspicion in England, one of the few men who 
believed in the genuineness of the stones from the first being 
the late Professor Tennant, of King's College, London. A 
writer in the Geological Magazine for 1868 concludes a rather 
long attempt to discredit the discovery with the words, ' I 
can only now conclude by expressing my conviction that the 
whole diamond discovery in South Africa is an imposture, a 
bubble scheme.' Nevertheless, the industry has grown to large 
proportions. Waterworks for the purpose of washing have 
been erected, and railways from the coast to the diamond dis- 
trict are in the course of construction. In the year 1881 dia- 
monds to the value of 3,685,0007. passed through the post 
office. 

The first diamond on being submitted to the authorities 
was valued at 5oo/. Considerable excitement followed the 
discovery, and the natives commenced searching for diamonds, 
in which they were successful. One diamond was found at 
83 carats, and was valued at i5,ooo/. 

In the year 1868 the colonists searched for diamonds on 
the river Vaal, and succeeded in finding a considerable number. 
On the Transvaal side of the river the centre of the diggings 
is Klip Drift, and on the opposite side is Pniel. There are 
about fourteen river diggings in all. Du Toit's and Bultfontein 
mines were discovered in 1870. They are twenty-four miles 
from the diggings on the Vaal. De Beers and Kimberley were 
discovered in 1871, and in 1872 at the river diggings a great 
diamond of 182 \ carats was found by Mr. Spalding. 

The last four land mines lie within a reef which surrounds 
them on all sides. This reef is comprised near the surface of 
loose shale, which gives trouble to the miners by falling 
in. This is succeeded in depth by a trachytic breccia and 



1 88 EARTHY AND OTHER MINERALS. 

augite. Below these are thin bedded strata to an unproved 
depth. 

Inside the reef the surface soil is red and sandy. Below 
this comes a yellow calcareous gravelly deposit, under which 
the ground is of a blue and slaty nature, and in this lies the 
chief source of the diamonds. Diamonds of a large size have 
been found in the yellow ground, and the Kimberley mine has 
been productive from the surface, but usually these upper strata 
are not profitable to work. 

At first in excavating the pits or holes, inclined roads, 
usually running north and south, were left up, but these gradually 
falling in, windlasses were resorted to, to be followed in 1873 by 
horse-whims. These gave way in the best mines in 1876 to 
steam-engines. In the early stages of working, when the 
diggers thought the red sand was the limit of the diamond 
deposit, the soil was simply turned over. When the underlying 
yellow ground proved to be productive the soil had to be 
removed a second time, and when the blue ground proved to be 
most productive of all, the same process had to be repeated at 
great cost. The mines or excavations are mostly irregular in 
shape, but some have been carefully laid out, and the shafts 
communicate with underground galleries. The Kimberley mine 
in 1882 covered 21 acres. The first diggers treated, on an 
average, eleven loads a day. Now, where a steam-engine is 
employed, a maximum of 2 50 loads a day is reached. The 
cost of working with present appliances is for the first hundred 
feet in depth 3^. 6d. per load, the second hundred feet, mostly 
in blue ground, 5^., the third 8^., and the fourth us. The 
yellow soil is loose and easy to work, but the blue requires 
blasting. Since mining operations commenced the price of 
labour has risen from 2os. per month to 30^. per week, with 
food. The following particulars, extracted from the published 
report of the De Beers Mining Co. of May 7, 1883, furnish 
much interesting information as to costs and results of 
working. 

* DIAMONDS. It is a matter of regret that the very severe 
fall in the diamond market during the last six months of the 



STATISTICS OF AFRICAN DIAMOND MINING. 189 

year has prevented your directors' anticipations as to the yield 
per load being realised, but the company's improved position 
will be apparent by comparison of this with last year's results, 
as it will be seen that during the year, to March 31, 1882, 
96,439 loads ground washed yielded 76,859 carats diamonds, 
realising io4,552/. 8^. 8d., whilst during the past year 166,436 
loads washed yielded 149,396 carats, realising 158,6757. 4^. 3^., 
showing nearly twice the output, and an improved quality of 
ground in the better average weight per load. The following 
is a summary of the work done during the year : 

Blue ground on floors, April i, 1882 . . 3,000 16 cubic ft. loads. 
Do. deposited do. to March 31, 1883 . 179,785 

182,785 
Blue ground washed, April I, 1882, to March 

31, 1883, 180,582 floors' loads, estimated at 166,136 

(Discount of 8 per cent, being allowed for 
difference.) 

Leaving a balance on floors of 16,649 ,, 

representing a cost, including rates, of about 5^. per load, or 
4,ooo/., which, however, with the cost of spreading lumps as 
given below, your directors have not considered right to include 
in the balance sheet, although a distinct asset of the company. 

'The ground produced 149,396 carats diamonds, realising 
158,6757. ^s. 3^., giving, in spite of a fall of about 40 per cent, 
in the diamond market, an average yield of igs. \d. per load. 
The above weight includes 22,766 carats fine sand (17,032 
carats found by the company, and 5,724 carats found on per- 
centage). Besides the balance of blue ground as above, the 
company has 25,000 loads lumps spread out on its floors, 
representing a cost of 1,250/1, which are producing an average 
of two-fifths of a carat per load, showing that the ground, after 
allowing a percentage for black reef and high ground, has 
averaged for the year at least a carat per load. 

* The cost of production, including rates, maintenance, and 
wear and tear of machinery, has been i is. g^d. per load, leav- 
ing a profit of js. ^\d. per load. The following tables are 
given for your information : 



i go 



EARTHY AND OTHER MINERALS. 



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S 



FAMOUS DIAMONDS. 191 

'SEARCHING SYSTEM. The adoption of this system has 
caused a marked improvement in the company's finds. During 
the month of February, before the men were searched, the 
company's finds were, in the claims 658^ carats, and on the 
floors i,io8 carats, whereas during the month of March, when 
the system had been put in force, they were, in the claims 1,234 
carats, and on the floors 1,53 of carats, making a total increase 
in the latter month of 998^ carats.' 

At the present time considerable interest is attached to the 
discovery of diamonds in New Zealand. 

Among the great diamonds known may be mentioned 

1. One formerly belonging to the Crown jewels of France, 
weighing 6yf carats. 

2. The largest known, mentioned by Taverner as in the 
possession of the Grand Mogul, in form and size resembling 
half a hen's egg, and weighing 297 carats. This diamond 
was found in the mine of Colore, to the east of Golconda. 

3. A beautiful lemon-coloured diamond, formerly belonging 
to the Grand Duke of Tuscany, now belonging to Austria, 
weighing 139 carats, and said to be worth i53,682/. 

4. An eastern diamond, formerly belonging to Nadir Shah, 
Sultan of Persia. It is without flaws or defects of any kind. 
It is about the size and shape of a pigeon's egg. It was 
purchased by the Empress Catherine of Russia for about 
9o,ooo/. ready money, and an annuity of about 4,ooo/. in 
addition. 

5. The Pitt or Regent diamond, said to have been found in 
Malacca. It was bought by Mr. Pitt, then Governor of Ben- 
coolen, in Sumatra, and sold by him to the Regent Duke of 
Orleans, by whom it was placed among the crown jewels of 
France. It weighed 136^- carats. 

6. The Koh-i-Noor, or Mountain of Light, belonging to Her 
Majesty the Queen, and formerly the property of Runjet Singh. 
This diamond is one of the largest in the world, and is valued 
at 2,ooo,ooo/. sterling. 

The weight and value of diamonds are reckoned by carats, 
of which 150 are equal to 480 grains, or one ounce troy. The 



1 92 EARTHY AND OTHER MINERALS. 

average price of rough diamonds is about 2/. per carat, but the 
price increases rapidly with size, as shown by the following 
table of approximate value. 




A rough diamond of 3 carats is worth 72 
4 , 126 






5 

10 


' 


20O 
800 






20 




3,200 






30 

40 




7,2OO 
12,800 






50 
60 
100 




20,000 
28,800 
8O,OOO 



But the price will vary according to the demand, and at the 
present moment the diamond market is in a depressed state. 



PLUMBAGO, OR GRAPHITE. 

This mineral in its pure state is composed entirely of carbon , 
but it is usually found mixed with varying proportions of alu- 
mina, iron, lime, and other substances. Its uses are various. 
It is used in the manufacture of pencils, whence its name 
graphite. Mention is made of a document ruled with graphite 
in the year 1387. The mineral used for this purpose comes 
largely from Siberia, and Ceylon graphite was formerly used 
with that then obtained from the Borrowdale mines in Cumber- 
land. For many years it has been extensively used in the 
manufacture of crucibles used in chemistry and metallurgy, 
on account of its great fire-resisting properties. More recently 
it has been applied to lubricating uses, and the commoner kinds 
for grate-polishing. The use of carbon for electric lighting 
purposes promises to open out a vast addition to the uses to 
which this mineral may be applied. 

BRITISH ISLANDS. The most important graphite mine ever 
worked in England is that of Borrowdale, in Cumberland. It is 
recorded that ioo,ooo/. worth of the mineral has been extracted 
in a year, the price then being 45^. per Ib. The early history of 
the mine also shews the lawlessness of the times only a century 



BORROWDALE PLUMBAGO MINE, CUMBERLAND. 193 




1 94 EARTHY AND OTHER MINERALS. 

ago. A body of miners took forcible possession of the mine, 
overpowering the guard, which, in consequence of numerous 
robberies, had been placed to protect the property, the pro- 
ceeds of which were sold to Jews, who came regularly to the 
George Hotel, Keswick, to buy. In the year 1800 the entrance 
to the mine was protected by a building containing offices and 
an attiring-room for the men. In this room was a trap-door 
through which alone an entrance to the workings was to be 
gained. Between the years 1850 and 1860 it was estimated 
that there was still about 30,0007. worth of the mineral in reserve, 
but this seems now to be exhausted. In the year 1875 20 tons 
were returned as being raised. The last return was for the 
following year, 1876, when one ton only was obtained. The 
mine was worked about half-way up a mountain 2,000 feet high. 
The strata was of Lower or Cambro-Silurian age. They consisted 
of slate rocks, with interbedded greenstone, and felspathic trap- 
pean rocks. The graphite occurred in one of these trap rocks 
of a bluish colour, in the form of irregular masses and more 
regular beds, which were sometimes of considerable size. These 
were connected by numerous veins glazed with plumbago. 
Both the felspathic bed and its enclosed graphite were frequently 
cut off or interrupted by rents, fissures, and also dykes of other 
substances, which rendered the mining of the mineral rather 
uncertain. A plan of the veins and a section of the workings is 
given in figs. 48, 49. It is on record that the mineral was first 
discovered by a tree being uprooted by the wind between Gills 
and Fareys stages. At first the plumbago was only used by 
the neighbouring farmers to mark their sheep. Afterwards its 
true value was discovered. In 1778 the price realised was 30?. 
per Ib. In 1829 it was 35^., and in 1833 45^. per Ib. After- 
wards, through the introduction of the mineral from abroad, 
probably Ceylon, the price fell to 30^. per Ib. Some of the 
pipes and pockets of ore have contained as much as 30,000 Ibs. 
of ore. 

Early in the present century a graphite mine was worked 
near Cummock, in Ayrshire. The strata at this mine consisted 
of the following, in descending order : 



PLUMBAGO DEPOSITS IN SCOTLAND. 195 

1. Sandstone composed principally of concretions of greyish 
white quartz, with a few scales of mica interspersed. 

2. A bed of clay slate from 10 to 12 feet thick, passing in 
places into a flinty slate or basaltic hornstone. 

3. Greenstone disposed in globular distinct concretions, 
which contained imbedded portions of graphite. 

4. A bed of clay slate 12 feet thick, similar to No. 2. 

5. Another bed of greenstone from 3 to 10 inches 
thick. 

6. Graphite. This bed was from 3 to 6 feet thick, and was 
comprised of graphite and columnar glance coal. The graphite 
was found compact, scaly, and columnar. The glance coal 
was disposed in distinct columnar concretions, arranged like 
pillars of basalt. Both substances were intermixed, the graphite 
being included in the coal and the coal in the graphite ; and 
in different parts of the patches of greenstone were met with 
what seemed to be part of the original deposit. 

7. A layer of greenstone. 

8. Flinty slate 10 to 14 feet thick. 

9. Sandstone of similar structure to No. i. 

The graphite of Cummoch was more variable in quality 
than that of Borrowdale, but at the time it was considered that 
the deposit was extensive enough and the average quality good 
enough to warrant extensive workings. A graphite or black- 
lead mine, as it was called, was also discovered by accident, in 
the year 1816, in Glenstrathfarra, the property of Fraser ot 
Lovatt, who worked it for a short time. The rock in which 
the graphite occurred was gneiss of a micaceous character. It 
occurred in irregular masses, one of which was about three feet 
thick and several yards long. This was not throughout pure 
graphite, but was mixed with fragments of the constituents of 
the rocks felspar, mica, quartz, with precious garnet. Nume- 
rous other masses of a smaller size were also found. The 
graphite was scaly, foliated, and undulatory. It also varied in 
quality. The working was carried on for a short time, and 
5 tons were sold in the London market at 937. per ton, the 
expense of getting it being stated at i3/. a ton. The work, 



196 EARTHY AND OTHER MINERALS. 

however, came to an end, and at the present time there is not 
a graphite mine in the United Kingdom. 

In North Wales, however, at a little distance above the 
Bala limestone, see fig. 26, there is a bed of impure graphite of 
considerable thickness. This bed follows the course of that 
limestone throughout Montgomeryshire and Merionethshire, 
see fig. 25. I have seen it near Llansaintfraid and Penygar- 
nedd in the former county, and near Llanymawddy in the 
latter. It is worth the trial, as the bed is considerable, whether 
by cheap mining and careful washing this deposit could not be 
utilised for some of the purposes for which the mineral is in 
demand. A similar bed in like position occurs at Llangelenin, 
near Conway. 

The chief source whence the bulk of the mineral has been 
derived for many years is the Island of Ceylon. The earliest 
notice there is of the mining of the mineral in the island is 
contained in a report by Colonel Colebrooke in the year 1829, 
where he says, relative to a tax, ' Provision had been made for 
payment either in money or in grain, and also for the delivery 
of cinnamon and black lead.' At that period the graphite of 
Ceylon was growing in repute, for we find that in America the 
late Mr. Joseph Dixon, who was the founder of the graphite 
industry and manufacture in the United States, started his 
manufacture in October, 1827, using a compact graphite found 
in New Hampshire ; but seeing some of the specimens of the 
foliated variety brought from India by trading ships, he tested 
them, and procured a shipment, following it by another, and 
he finally adopted the Ceylon graphite entirely. The succes- 
sors of Mr. Dixon, the Dixon Crucible Co., New Jersey City, 
New York, and Battersea Crucible Co., London, have hitherto 
taken by far the larger part of the production of the island. 
No record of the quantity of the mineral annually raised was 
kept before the year 1846. Since that date the quantity ex- 
ported has been as follows : 

Cwts 

For the five years ending 1851 . . . . 13,410 
>, 1856 .... 13,950 

" l861 .... 37,530 



PLUMBAGO DEPOSITS OF CEYLON! 

For the five years ending 1866 . . 57- 

1871 .... 124,714 

1876 .... 137,474 

,, three years ,, 1879 .... 114,671 

It will thus be seen that the industry has been a growing 
one. The largest quantity exported in any single year was 
during the twelve months ending September 30, 1879, the 
quantity being 200,000 cwts. The quantity shipped in the 
year 1880 was nearly equal. The number of graphite mines 
and pits on the island is estimated at 400. The natives also 
often find lumps in the soil. The only information we seem 
to possess as to the geological conditions under which the 
mineral is found is contained in Dr. Gygax's Geological Sur- 
vey, 1848, Appendix No. 2 to ' The Reports exhibiting the 
Past and Present State of Her Majesty's Colonial Possessions,' 
where the Doctor says, ' Plumbago or graphite is found chiefly 
in the southern side of SarTragam, in the Kukuls Korle. It is 
believed to belong to the same formation as the anthracite, 
viz., to the upper strata of the Devonian formation. The prin- 
cipal mine is at Nambepane, and contains a large vein running 
from north-west to south-east. The ore is pure and crystal- 
line near the basalt, and compact and massive further from it. 
I believe this vein extends to a distance of forty or fifty miles 
towards the Bintenne country. The plumbago of Ceylon is 
pure and light, and now that a method has been discovered to, 
purify and compress it the value will rise.' 

As a matter of fact the price has fluctuated considerably. 
In 1868 and 1869 it fetched in Ceylon i2/. to i4/. per ton. 
In 1870, we are told in the provincial reports that the fall in 
the price is so considerable that it has put an end to the 
digging for the mineral on Government land. In 1872 there 
was a slight rise, and we read that in the Government of Galle the 
quantity raised was 22,751 cwts., and the average price 6 rupees 
per cwt., or 120 rupees per ton. From another province, in 
1873, we are informed that ' plumbago, which formerly sold at 
200 rupees per ton, is now only 90 rupees, and with the 



198 EARTHY AND OTHER MINERALS. 

enhanced value of labour it can scarcely be profitably worked.' 
In 1874 the trade was at its worst, and we are told that 
plumbago 'is practically unsaleable.' In 1880 the average 
price was slightly higher than in 1868-69, being i5/. per ton. 
The deposits are spread over large areas in the Government of 
Galle, in the Hambantota district, at the Rannialakand Moun- 
tain, and the hilly country forming the north-western boundary 
adjoining Matara. There are also numerous mines in the 
Matara district, and also in the Wenda Willi Hatpatta. The 
Government grant licences to work the mineral at a royalty 
which was formerly 10 rupees per ton, but upon representa- 
tions being made that this amount pressed hardly upon the 
poorer kinds of mineral, the royalty was reduced to 5 rupees. 
Shafts have been sunk, and attempts have been made to work 
the mines English fashion, but for the most part the deposits 
are worked open and near to the surface. The favourite 
mining district at present is the neighbourhood of Kurunegela, 
Awisawella, Ratnapura, and Kalutara. The natives are guided 
by lumps and grains in the soil, and by the croppings up of 
the rock. No geological survey has been made. 

From 4,000 to 5,000 men are employed at the mines, and 
about 500 carters, with their carts and a pair of bullocks each, 
cart the mineral to Colombo. A good deal of the preparation 
of the mineral for the market is done at Colombo, women 
being largely employed. At first the Cingalese women had a 
strong prejudice against touching the mineral, but now they 
like the work, and are experts. One proprietor in Colombo, 
Mr. W. A. Fernando, whose family have long been connected 
with the trade, employs about 150 men and women. The 
men are paid from 50 to 75 cents a day, and the women 25 to 
30. Mr. Fernando has large sheds, roofed with cocoanut- 
leaves the dust blown about makes everything so slippery 
that slates would fall off. The plumbago is first washed in 
large baskets, the smaller pieces and dust being spread upon 
an asphalte floor to dry. By this means the quality is dis- 
covered by the practised eyes of the pickers, who separate 



PLUMBAGO DEPOSITS IN NORTH AMERICA. 199 

pieces affected by iron ore, pyrites, quartz, or other foreign 
materials, a very small quantity of which would spoil the 
mineral for crucible-making. The good lumps have the dust 
brushed off, and are polished with cocoanut husks. The 
mineral is separated into four sizes by means of perforated 
plates of iron. It takes about 100 expert men and women to 
prepare about 3 tons a day of the smaller stuff. The ore 
is brought from the mines to Colombo in casks holding about 
5 cwt. each, and also for shipment. Some 35,000 casks were 
required for this latter purpose in the year 1879. 

UNITED STATES OF AMERICA. The Dixon Crucible Com- 




FIG. 50. SECTION OF THE BLACKLEAD MOUNTAIN, TICONDEROGA, ESSEX COUNTY, 
NEW YORK. 

iii, Beds of Plumbago. 222, Gneissic Rocks. 

pany, already referred to as large consumers of Ceylon graphite, 
have within the last six or seven years obtained the mineral also 
from a mountain locally known as the Blacklead Mountain, 
which rises close to the village of Ticonderoga, Essex County, 
State of New York. The graphite beds are interstratified be- 
tween gneissic rocks, as shown in fig. 50. The beds dip at an 
angle of 45 degrees. The ore in them is chiefly of the foliated 
variety, and is mixed with gneiss and quartz in the beds, in 
veins or layers from i to 8 inches in thickness, some of the 



200 EARTHY AND OTHER MINERALS. 

deposits being richer than others. One of these, as shown in 
the figure, has been followed to a depth of 350 feet. It is 
found of varying thickness, and it opens out at times into 
pockets. When separated from the attached materials this 
graphite is of fine quality. It is sent downhill from the mine 
to the works a distance of two miles where it is crushed 
with a stamp-battery, and the ore is then washed and separated 
in Cornish buddies and settling-tanks. The separated graphite 
scales are then ground in water to the fineness required for 
the different uses, as crucibles, lubricants, pencils, and ordi- 
nary blacklead. The industry is an old one. In the year 
1822 the mineral was removed from the gangue by means of 
chisels, pickaxes, and iron bars, and conveyed to the falls, 
where it was pulverised and purified. In the manufacture of 
pencils the very finest grained graphite is used, and is mixed 
with clay. Graphite is found in various other localities in 
America in the older rocks of the Appalachian Mountains, 
stretching from Canada to Alabama. 

It is said to occur in great purity in five different localities in 
Albany county, Wyoming Territory, in veins from i foot 6 inches 
to 5 feet thick. At Pilkin, in Gunnison County, it occurs massive 
in beds 2 feet thick, but of impure quality. Indeed, it would 
seem that the massive beds everywhere were the most impure, 
the redeposited mineral in cracks and cavities being the purest. 
In New Mexico it is found in a pure form in the Coal- 
measures, possibly as the result of heat, which has driven 
all bituminous matter away, and of a redisposition of the 
particles. It is also found in the Black Hills of Dakota, and 
it has been mined at the Sonora mine, Tuolomme County, 
California. 

It is also found in Canada, and the following table of 
analyses is from the report of a survey and inquiry authorised 
in 1876 by the Canadian Government as to the comparative 
merits of graphite from Canada and Ceylon. Graphite also 
occurs on the American side of Behring's Straits, where the 
natives use it for the ornamentation of their persons. 



USES OF PLUMBAGO. 



201 



ANALYSES OF CANADIAN AND CEYLON GRAPHITES. 



Locality. 


Specific 
Gravity. 


Vola- 
tile 
matter. 


Carbon. 


Ash. 






Per 


Per 


Per 






cent. 


cent. 


cent. 


Canada, Buckingham, vein graphite, 










variety foliated ..... 


2-2689 


0-178 


99-675 


0-147 


Canada, Buckingham, vein graphite, 










variety columnar 


2-2679 


'594 


97-626 


1-780 


Canada, Grenville, vein graphite, variety 










foliated 


2-2714 


0-109 


99-8I5 


0-070 


Canada, Grenville, vein graphite, variety 










columnar 


2-2659 


0-108 


99757 


0-135 


Ceylon, vein graphite, variety columnar . 


2-2671 


0-158 


99-792 


0-050 


Ceylon, vein graphite, variety foliated 


2-2664 


0-108 


99-679 


0-213 


Ceylon, vein graphite, variety columnar 


2-2546 


0-900 


98-817 


0-283 


Ceylon, vein graphite, variety foliated 


2-2484 


0-301 


99-284 


0-415 



In Canada, New York, and Pennsylvania it occurs chiefly 
in veins and pockets in strata associated with gneissic rocks. 
It is associated in the veins with calcite, quartz, pyroxene, 
mica, and apatite ; and the crystals of calcite, on being 
split, show scales of foliated graphite along the lines of 
cleavage. 

The new report on the mineral resources of the United 
States, edited by Albert Williams, and published by the 
Government, gives the following particulars concerning the 
uses for which the mineral is employed, and it is stated that 
no less than 150,000,000 pencils are now manufactured in the 
world. The quantity of graphite imported into America in 
1882 was 16,047,100 Ibs., of which the greater part came from 
Ceylon, and the rest from Germany. 

The properties of graphite make it useful for the fol- 
lowing general purposes : the manufacture of refractory 
articles, lubricants, electrical supplies, pigments, and pencil- 
leads. A detailed table of the articles made from it is 
annexed, with an estimate of the percentage used for each 
purpose : 



202 



EARTHY AND OTHER MINERALS. 



PROPORTIONATE AMOUNTS OF GRAPHITE USED FOR DIFFERENT 
PURPOSES. 



Manufactures. 


Kinds of graphite used. 


Per 
cent. 


Crucible and refractory articles, as stop- 
pers and nozzles, crucibles, &c. . . 
Stove-polish 


Ceylon, American . . . 
Ceylon, American, German 
American, Ceylon . . . 
Ceylon, American, German 
American 


35 
32 

10 

8 
6 
3 
3 

2 

1 

i 

100 


Lubricating graphite 
Foundry facings &c .... 


Graphite greases 


Pencil-leads ' . 


American and German. . 
Ceylon, American . 
Ceylon, American . . . 
American 


Graphite packing . . . 


Pol ; shing shot and powder. . . . . 
Paint . . . 


Electrotyping 
Miscellaneous piano-action, photo- 
graphers', gilders', and hatters' use, 
electrical supplies, etc 


American, Ceylon . . . 







Graphite is also, as before stated, largely and increasingly 
used as a lubricant, both by itself and mixed with fat or grease, 
in various proportions. 

JET. 

In appearance this mineral resembles cannel coal ; but it 
is harder, and is capable of receiving a high polish. It is also 
of a deeper black colour. It receives its name from the river 
Gages, in Lycia, in the alluvium of the mouth of which it was 
found in the time of Pliny. The small pieces of the mineral 
found there were called gagates, subsequently ##/, and ulti- 
mately jet. It has formed the subject of a considerable industry 
along the eastern side and seacoast of Yorkshire from very 
early times. The Danes, and subsequently the Romans, seemed 
to have worked it for ornamental purposes. A good specimen 
from Whitby, on analysis, showed the following composition : 

Carbon 79'97 

Hydrogen 4-30 

Nitrogen ...... 0*47 

Oxygen 13-22 

Sulphur 0-91 

Ashes 1-33 



100-00 



JET MINES OF YORKSHIRE. 203 

It is found in the harder portions of the alum shale rock of 
the Lias. The rock is from 6 to 7 yards thick, and in this 
the mineral is found in small patches, and in quantities from a 
few ounces to two hundredweight. On the south it is found 
a little way south of Whitby, northward in the Mulgrave mines, 
then in those of Lord Dundas, terminating at Skinninggrove 
Beck. It then turns westward by Eston and the Guisbro' 
mines, and the mineral is found in all the valleys of the tribu- 
tary streams of the Esk. 

A softer kind is also found near Whitby, called soft jet, 
from which an inferior kind of article is made. 

The mineral is obtained by excavating the face of the 
cliffs, and following it in old quarry workings. It is said that 
all attempts to mine systematically have been unsuccessful, 
although the price of the best qualities is from I2S. to 14^. 
per Ib. It is found in Russia in sand and gravel beds, where 
it is called black amber, from its being electrical when rubbed, 
like amber. The production of jet in England in the year 
1880 was 6,720 Ibs. 



2O4 



CHAPTER XII. 

CA RBON continued. 

Asphaltum, Varieties of History of the Uses of Bituminous Substances 
Of the American Petroleum Industry The Cannels of Flintshire 
and Lancashire Modes of Occurrence The Torbane Hill Mineral 
The Bituminous Deposit of Bovey Tracey Deposits of Bituminous 
Matter in Silurian Strata in Ireland Bitumen in France Gneiss in 
Sweden Bitumen Deposits of France Asphalte of the South of 
France Bituminous and Petroleum Deposits of Germany The 
Hanover Oil-well Region. 

BITUMEN AND BITUMINOUS SUBSTANCES. 

BITUMEN occurs in nature in various degrees of fluidity and 
solidity. The solid varieties are of a black, brown, or reddish 
brown colour. The fluid varieties are transparent, and vary 
from colourless to yellowish white and dark brown. The 
following are the chief varieties of bituminous substances. 

ASPHALTUM (Mineral Pitch). Chemical composition: 76 
to 88 carbon, 2 to 10 oxygen, 6 to 10 hydrogen, and i to 3 
nitrogen. Specific gravity, 1*0 to 1*2. Hardness 2. In colour 
and appearance pitch black, opaque, resinous. Has a strong 
bituminous odour. 

MINERAL CAOUTCHOUC (Elaterite or Elastic Bitumen). 
Chemical composition : 84 to 86 carbon, 12 to 14 hydrogen, 
and a little oxygen. Resinous colour, yellowish brown, and 
black. Occurs in kidney-shaped lumps ; has a strong bitu- 
minous odour. 

RETINITE (Retin- Asphaltum). Composed of carbon, 
hydrogen, and oxygen in uncertain amounts ; composition 
sometimes given as vegetable resin 55, bitumen 41. Occurs 



EARLY NOTICES OF BITUMINOUS SUBSTANCES. 205 

in roundish masses varying in colour, light yellow, brown, and 
green. Flexible and elastic when first obtained, but losing 
these qualities on exposure to the atmosphere. 

PETROLEUM (Fluid Bitumen}. In its natural state it is 
dark yellow, brown, and dark brown in colour. Its chemical 
composition will be given in detail further on. 

NAPHTHA or Mineral Oil. Chemical composition : carbon 
84 to 88, hydrogen 12 to 16 ; colourless to yellow. Before 
describing the conditions under which bituminous substances are 
found it may be well to give a brief general history of their use, 
more especially their use for lighting and heating purposes. 

Perhaps the earliest reference we have is contained in the 
Scripture account of the building of the Ark and of the 
Tower of Babel. In the region assigned to that building 
bituminous matter is still abundant, and floats on the waters of 
the rivers. Herodotus, writing 440 years before the commence- 
ment of the Christian era, describes a place, Aderrica, situated 
thirty-five miles from Susa, where there were wells yielding salt, 
bitumen, and oil. The oil was drawn from these wells by means 
of skins, and was placed to settle in tanks. The more solid 
matter, salt and bitumen, fell to the bottom, and the oil was 
drawn off for use. The oil had an unpleasant smell, it was 
black in colour, and it was called by the natives Rhadinace. 

Along the shores of the Caspian, and southward down the 
valleys of the Euphrates and Tigris, similar oils are still 
obtained and used by the inhabitants. 

The oil from the wells of Rangoon, in Burmah, has also 
been in use from very ancient times. 

About one hundred and thirty years ago the Philosophical 
Transactions, the Transactions of the Royal Society of Great 
Britain, and the scientific papers of other countries of Europe, 
contained references to the distillation of oils from coals, and 
of the experiments made towards purifying them. A century 
ago the Earl of Dundonald distilled these oils from coal in 
ovens similar to those now in use for the manufacture of coke. 
On the continent of Europe, a quarter of a century later, oils 
distilled from the tars obtained from bituminous schists by 



206 EARTHY AND OTHER MINERALS. 

Laurent, Reichenbach, and others, and purified to some extent 
by Selligue, were extensively used for burning and lubricating 
purposes. 

In connection with the discovery and utilisation of gas, 
about the same time and subsequently, experiments were made 
and improvements introduced in the purification of the various 
oils obtained from coals. 

In 1830 M. Selligue obtained a light paraffin oil from the 
bituminous shales of Feymoreau, in the Bourbon Vende'e, 
France, together with a heavier oil and a lubricating oil and 
solid paraffin, by a method which is said to have been 
identical with that patented by Mr. James Young for the 
Torbane Hill mineral in the year 1850. 

In America Dr. Abraham Gesner first successfully obtained 
lamp-oils from coals in the year 1845. These oils were burnt 
by him in lamps used by him at the public lectures given by 
him at Prince Edward's Island in the following year, and at 
others afterwards delivered at Halifax, Nova . Scotia. Patents 
were subsequently obtained for the manufacture of kerosene 
oil by his process. 

In England, in 1847, Mr. Charles B. Mansfield obtained 
patents for * an improvement in the manufacture and purifi- 
cation of spiritous substances and oils applicable to the 
purposes of artificial light.' Mr. Mansfield's experiments seem 
to have been the base of the attempts to introduce the 
atmospheric light obtained from the use of the lighter oils or 
spirits, as benzole, in conjunction with atmospheric air. 

In October, 1850, Mr. James Young, of Manchester, 
obtained a patent for the * obtaining of paraffin oil, or oil 
containing paraffin, from bituminous coals,' and in March, 
1852, Mr. Young obtained a similar patent for the United 
States. In defending these patents against manufacturers who 
were, by the processes they employed, supposed to be infring- 
ing the patents, much litigation was caused. Happily the 
result was that a great and rising industry was left unfettered, 
and no exclusive right was established in results which seem 
to have been gradually evolved by much thought and expense, 



DISCOVERY OF PETROLEUM IN AMERICA. 207 

and by many experiments, during a whole century. The dis- 
tillation of oils from cannels and bituminous shales grew in 
the Flintshire coal-fields and in the coal-fields of America, as 
well as in most of the great cities of the Atlantic coast. 

In 1853-4 kerosene oil of great lighting power but of un- 
pleasant odour was introduced to the public in America by 
Messrs. J. H. and G. W. Austen, the agents of the North 
American Kerosene Gas-light Co. of New York. Safety and 
comfort in the use of this oil were further increased by 
the introduction into America by Mr. J. H. Austen of the 
adaptation of a burner which he had seen in use in Vienna. 

In the course of the six following years the distillation of 
oil from natural petroleum almost entirely superseded the dis- 
tillation from coal and shale. Petroleum had been collected 
from remote times in the State of New York by the Seneca 
Indians, and after them it had received the name of Seneca 
oil. 

In the year 1854 petroleum was obtained from an old salt 
well at Tarentium, on the Alleghany, near Pittsburg, where its 
presence in quantity impeded the manufacture of salt. This 
was finally introduced successfully in New York by Mr. A. C. 
Ferris, in the year 1857. In 1858 the first petroleum well 
was bored by Mr. E. L. Drake, at Titusville, on Oil Creek, 
in Pennsylvania, with a successful result. The growth of the 
industry was after this most marked and rapid. 

In the year 1861, three years after the boring of the wells 
at Titusville, the production of petroleum oils in the United 
Stales amounted to 24,000 gallons per day. 

In 1862 40,000 per day. 

,, 1803 70,000 ,, ,, 

,, 1864 87,000 ,, ,, 

,, 1865 91,000 ,, 

In the year 1882 the daily production reached the great total 
of 2,145,000 gallons per day. 

These amounts are exclusive of the oil produced in Canada. 

We will now notice the manner in which these bituminou 



208 



EARTHY AND OTHER MINERALS. 



substances occur in nature, and the localities from which they 
are obtained, beginning, as usual, with the British Islands. 

Bituminous matter forms part of the composition of the 
greater part of our coal-seams, the exception in this country 
being found in the western end of the South Wales coal-field, 
and in portions of the coal-fields of Ireland, where it would 
seem as if the bituminous matter had been driven off subsequent 
to the deposition of the coal-seams, possibly by the heat evolved 
during the great disturbances which have so crumpled and 
broken the strata. 

Bitumen is especially present in the variety of coal known 
as cannel. This form of coal is most prevalent in the lower 
yard coal of Denbighshire and Flintshire, and in the equivalent 
seam in the Lancashire coal-field, as well as in what may be 
the same seam in the Newcastle coal-field. 

In the Flintshire coal-field a great deal of cannel coal and 
its associated shale was used for the production of paraffin oils 
and products before the influx of petroleum from America at 



ik 




FIG. 51. SECTION OF YARD COAL SEAM, FLINTSHIRE, SHOWING DEPOSIT OF CANNEL. 

i, Coal Seam. 2, Deposit of Cannel in Coal Seam. 3, Bituminous Shale Floor. 
4, Bituminous Shale Roof. 

so cheap a rate made the manufacture unprofitable. The 
lower yard coal of the two counties of North Wales referred to 
is about a yard thick. The cannel form occupies but portions 
of the seam, filling up depressions in the ordinary coal, as shown 
in fig. 51. 

In the cannel all vegetable fibre and organic structure, 
such as are seen in the other parts of the seam, are completely 
destroyed, and the coal appears as a hard pitchy mass. At 
such points also the under clay gives place to a bituminous 



CANNEL OF FLINTSHIRE. 209 

shale, and in this and in the overlying shale of a similar cha- 
racter there are numerous fish remains, only indistinctly 
preserved. Where these coals and shales are in their perfect 
form, as about Leeswood, near Mold, the following is the order 
downwards : 

1. A rich oleaginous shale 4 to 10 inches thick. 

2. Smooth cannel 2 feet 3 inches. 

3. Curly cannel I foot 6 inches. 

4. Floor of highly bituminous shale. 

The smooth cannel (2) has a flat conchoidal fracture, and it 
passes downwards into the curly cannel. The curly cannel 
(No. 3) has a lustrous appearance. It is compact, and has 
a slightly conchoidal fracture. It abounds with flat circular 
disc-like appearances. It has some sulphide of iron, and shiny 
specks of arsenical pyrites. In the floor of bituminous shale, 
as well as in the roof shale, fish remains are abundant. Some 
years ago Dr. Andrew Fife, of Aberdeen, gave the following as 
the illuminating power of the various minerals named : 

Cubic feet of 
Gasper ton. 

Wigan cannel 12-01 

Lesmahago coal .10-176 

Torbane Hill mineral . ^ . . 15*482 

Leeswood smooth cannel .... 9'972 

Leeswood curly cannel ... ..' . . 1 4' 28 

In places where the conditions have been favourable, the 
bituminous coals of Flintshire have passed again into a liquid 
form. Thus recently, in a colliery on Buckley Mountain, in 
Flintshire, a flow of oil was tapped in the workings. 

In the neighbouring county of Shropshire, a bituminous 
spring has long been known in the parish of Wombridge, near 
Broseley. In the early part of the eighteenth century this 
spring is said to have yielded near a thousand gallons a week. 
In the year 1799 it only yielded about thirty gallons a week. 
At present it is not used commercially. The spring flowed 
from a fissured sandstone in the Coal-measures, having coals at 
a little distance above and below, and irregular patches of coal 
in it. An adit was driven in the sandstone, which facilitated 



2IO 



EARTHY AND OTHER MINERALS. 



the flow and collection of the oil. It is interesting to note 
that the water exuding from and near to the Flint coal one 
of the lower coals of the Shropshire coal-field is salt, and salt 
springs abound in the Coal-measures of the neighbourhood, 
some of which were formerly found of sufficient strength to 
work. 

Perhaps the most interesting deposit of bituminous mineral 
in Great Britain, from its great commercial value, the part it 
has played in the development of the paraffin industry, and the 
litigation of which it has been the subject, is that of Torbane 
Hill, near the Firth of Forth, in Scotland. This deposit occurs 
in beds that lie below the ordinary coat-seams of the Lanark- 




FIG. 52. SECTION SHOWING THE POSITION OF THE TORBANE HILL MINERAL. 

i, Lanarkshire Coal-measures. 2, Beds of Fresh-water Limestone on the N.N.W., with 
Shales and Coals on the S.S.E. 3, Shales, Sandstone, and Tutaceous Beds. 

shire coal-field. Fig. 52 is a very general section of the strata 
of this field. 

The Torbane Hill bed lies in group 2, on the north-north- 
west side of the section. It is associated with several coal- 
seams, and with them it occupies a small mineral basin about 
three square miles in area. These coal-seams and the particular 
bed itself are interstratified with two or three beds of fresh-water 
limestone. As will be seen, it underlies the ordinary Coal- 
measures. Bitumen occurs in a solid form in the underlying 
sandstone beds, and in round nodules in the limestones, as 
well as in contiguous trap' rocks, from which it also oozes out 
in a liquid form. 

The mineral contains volatile matter . . .70- 10 
,, ,, carbon or coke . . . 10-30 
, ash 19-60 

It yields 120 gallons of crude oil per ton. This, with the 



BOVEY TRACEY BITUMINOUS DEPOSIT. 211 

exception of the bitumen of Ritchie County, Virginia, which 
gives 170 gallons, and the Breckenridge coal of America, which 
yields 130 gallons, is the largest quantity of oil yielded by 
bituminous substances. This mineral has been very largely 
used for the production of paraffin and its products. It was 
used under a patent by Mr. Young in the year 1850, and 
Young's paraffin oil, which gave the start to the use of mineral 
oil lamps in this country, was made from it. It was also 
extensively exported to the United States of America, and 
was used there in the manufacture of kerosene, in the produc- 
tion of which 200,000 tons were used in the year 1859 by the 
North American Kerosene Gas- Light Company, at their works, 
Newtown Creek, Long Island. The manufacture of oil from 
this mineral led to a vast amount of litigation ; part of this lay 
between Mr. Young and the distillers of oil from cannel in 
England and the producers of petroleum in America, which 
happily ended in unrestricted manufacture, and part with the 
owners of the ground. The great question was whether the 
mineral was coal or not coal. The bulk of the evidence went 
to prove that it was not coal, but a bituminous shale or clay. 
Compromises resulted, and the use of the name coal was 
retained, although, as it has been suggested, the name might 
as well be given to the bitumen of the Great Pitch Lake of 
Trinidad. 

A deposit of bituminous coal occurs, and has at various 
times been worked, near Bovey Tracey, in Devonshire. The 
deposit occurs in clays and sands that overlie the Greensand, 
and is of Tertiary age. The beds are from 4 to 16 feet thick, 
and are interstratified with the clays. It contains 42 per cent, 
of volatile matter, 58 per cent, of coke, and it yields 50 gallons 
of crude oil per ton. It abounds in the remains of fish, 
Crustacea, and other marine organisms, and hence, like the crude 
oil of Canada derived from strata containing similar remains, 
it has a very strong smell. The oil contains a greater number 
of the equivalents of carbon than do the oils derived from 
coals or ordinary bitumen, and hence it is found to smoke in 
ordinary lamps. 



212 EARTHY AND OTHER MINERALS. 

It seems to have been first raised for use about the year 
1700, and was subsequently being worked by means of pits 
about 80 feet deep. It is recorded that the offensive smell 
emitted by the mineral prevented its use for domestic purposes 
except by poor cottagers of the neighbourhood. It ceased to 
be worked about the beginning of the present century ; but when 
the demand for oil shales sprang up, consequent upon the 
introduction of paraffin, and preceding the general use of 
American petroleum, a brief period of mining activity ensued ; 
but the unpleasant smell and the density of the oil rendered 
permanent success impossible. It has, however, been used at 
various times in potteries that have been established for working 
the adjacent clays. 

In Ireland, bituminous matter is occasionally seen oozing 
out of Silurian strata. More important was the attempt to 
manufacture paraffin from peat, which, during the demand for 
oil-producing substances, was made on an extensive scale by 
the Irish Peat Company in Kildare. As the use of peat may 
again be resorted to when the bulk of the petroleum wells have 
failed, it is well to place on record the results obtained by this 
company from one ton of peat. 

Liquids not oily 65 galls. 

Tar . . . . . . . . 6 

From which were obtained 

Lamp oil . . . . . 2 

Lubricating oil i gall. 

Paraffin 3 Ibs. 

Ammonia 3 

Acetic acid 5i > 

Naphtha 8 

with 25 per cent, of charcoal. 

SWEDEN. Bituminous matter, of more interest geologically 
than commercially, occurs at Millaberg, Wermland, Sweden. 
As shown in fig. 53, it occurs in gneissic rocks, and derives its 
interest from the fact that it shows the presence of vegetable 
matter in some force in strata of Laurentian age. 

FRANCE. At Feymoreau, near Fontenay le Comte, in the 



BITUMINOUS DEPOSITS OF FRANCE. 



213 



Bourbon Vendee, is a small coal-field that stretches between 
Nantes and Rochelle, from some of the strata of which, as I 
have already stated, paraffin oils and products have been 
obtained for many years. The strata from which these products 
were, and it may be are still, obtained underlie a coal of inferior 
quality. They do not contain any vegetable impressions, 
which, we have seen, is usually the case where coal passes into 
a highly bituminous state, as in cannel. The shales are of a 




w E 

FIG. 53. SECTION AT MILLABERG, WERMLAND, SWEDEN. 

i, Reddish Granitoid Gneiss. 2, Gneiss. 3, Fine-grained Gneiss and Mica Schist. 
4, Thin Strata of Bituminous Schist. 

deep black colour, and when first mined are tough and hard, 
but they soon fall to pieces on exposure to the atmosphere. 
They burn freely, with much smoke and a long flame. They 
are not, however, uniformly bituminous. In places these shales 
reach a thickness of from 30 to 40 feet. Ordinarily they yield 
about 15 per cent, of light oil, on slow distillation, with 60 per 
cent, of ash and some water. They belong to the ordinary 
Coal-measures. 

On the other side of France, about Autun, is another small 
coal-field of ordinary Coal-measure age. Here bituminous 
schists, like those of Feymoreau, occur much higher up on the 
series, and several hundred yards above the highest coal-seam. 
At Cordesse these schists are about 10 feet thick. They are of 
a reddish brown colour, but become black on exposure to the 
atmosphere. Some of the beds are pyritous ; the quantity of 
oils of all kinds yielded by them varies from 6 to 50 per cent. 
They are worked partly by open quarrying and partly by drifts 



214 EARTHY AND OTHER MINERALS. 

or adit levels, as is common in the coal mines of South Wales. 
The manufacture of paraffin, paraffin oils, and other products, 
has been carried on here since the year 1835 with varying 
success, the industry here, as well as in England, having been 
greatly affected of late years by the exportation of good oils at 
very low prices by America. 

Of very great importance commercially in another direction 
that of the construction of roadways are the bituminous 
deposits of the banks of the Rhone, near Bellegarde. 1 These, 
with some of the uses of the bitumen, seem to have been dis- 
covered in the year 1721 by Dr. Eyrinis, who thought that in 
the bitumen he had discovered a panacea for all the diseases 
to which human nature is liable. It is on record, however, 
that from time immemorial the inhabitants have noticed bitu- 
men; hence the name of the principal hill Pyrmont. In the 
fifth year of the Republic a gentleman obtained a concession 
from the Directorate, his idea being to work the mineral for 
home consumption. 

The concession extended along the two banks of the 
Rhone from Bellegarde to Seyssel 4 kilometres. It is from 
the last-named place that the chief mine of the district takes its 
name. 

When the application of bitumen mixed with chalk began 
to extend, Secretan, the lessee, opened a mine and established 
a manufactory for the production of mastic. At this juncture 
some of the inhabitants disputed his right, on the ground that 
the concession had been obtained for bitumen only, contend- 
ing that the use of bituminous chalk is different from that of 
free bitumen, and that the working of a quarry was not under 
the same law as was the working of mines. 

After much deliberation, the Council of Mines decided that 
the works at Seyssel constituted a mine and not a quarry, and 
that the concession included the right to extract chalk as well 
as bitumen. 

In the year 1843 these rights were finally confirmed, and in 
the meantime the mine continued to be the chief source of 
1 L. Malo, Fabrication de VAsphalte et des Bitumes. 



ASPHALTE MINES OF SEYSSEL. 215 

mastic. The output was, however, restricted until about the 
year 1838, when the use of asphalte in the construction of foot- 
paths gave increased importance to and extended the operations 
of the mine. 

In the year 1855 the production had risen to 1,500 
tons yearly. In 1863 it had increased to 10,000 tons, and the 
production continued large subsequently. 

The deposit at Seyssel consisted of a hill 400 metres long 
by 100 metres wide. It consists of chalk surmounted by beds 
of Greensand. 

The chalk is made up of three layers of bituminous chalk 
from 3 to 4 metres thick, which are separated by three layers 
of white chalk not impregnated with bitumen, and which vary 
from i to 15 metres in thickness. 

In the impregnated layers the chalk is in places highly 
crystalline, and in others it is made up of shells, among which 
fishes' teeth are found. The bitumen occurs in cracks, cavities, 
and layers. It forms from 8 to 10 per cent, of the whole 
mass. 

The theory has been suggested that this bituminous matter 
has been derived from carbonaceous deposits far below, which 
have been slowly distilled by volcanic or chemically produced 
heat, the vapour arising and subsequently condensing, filling 
the pores and interstices of these Upper Jurassic strata. There 
are small proportions of arsenic and of manganese present, but 
the purer the containing chalk is, the better is the result in the 
manufactured asphalte. 

It is possible, however, that it may have been derived from 
carbonaceous matter that formed part of the overlying strata 
which have been subsequently denuded, but of which traces 
here and there remain. 

The mineral is got from the beds in blocks of different 
sizes, by means of quarrying in open excavations, the amount 
of top rock to be removed not being very great. In winter the 
rock is hard like ordinary chalk, and the drill works freely, but 
in summer the bitumen softens, and the rock is elastic. This 
destroys the ordinary action of the powder, and picks and 



2l6 EARTHY AND OTHER MINERALS. 

wedges have to be used. In some other deposits which are 
worked underground as ordinary mines, this difficulty does not 
occur. There are several smaller deposits scattered about the 
neighbourhood of Seyssel which have been more or less 
worked, but the description just given will apply generally to 
them all. 

Bituminous springs and deposits abound over the plain of 
La Magne, in Auvergne, some only of which have been ex- 
plored. The mineral is of two kinds, calcareous and sandy. 
It is of a reddish colour and a pronounced arsenical odour. The 
principal springs are at La Fontaine de Paix, on the road 
between Pont du Chateau and Clermont. They give some hun- 
dreds of kilogrammes during the summer, but they are stopped 
during the winter. 

Another important bituminous deposit, which is of the same 
geological age as that of Seyssel, is that of the Val de Travers, 
on the right bank of the Reuse. This deposit was also dis- 
covered by Dr. Eyrinis. It subsequently passed through 
several hands, and, with Seyssel, was made the base of extensive 
gambling transactions by speculators; but about the year 1860 
it got into regular work, and is now an important source of the 
asphaltum of commerce. 

Here the principal bituminous layer forms a lenticular mass 
of about 8 yards in thickness and 160 yards in breadth. It is 
covered immediately by an asphalt earth known as ' scrap,' 
and this is overlaid on the surface by a thin layer of vegetable 
matter. The deposit is richer in bitumen than those of Seyssel, 
and contains from 12 to 13 per cent, of bitumen. It is, or was 
until recently, worked as an open quarry. 

GERMANY. The slates below the brown coal of Tertiary 
age on the Westphalian side of the Rhine are very bituminous. 
They have been worked to a considerable extent, and the 
products have been manufactured at Beul, opposite Bonn. 
These shales are very thin, and they are known as ' blatte,' or 
paper-coal. 

At Bamberg, in the north of Bavaria, and at Reutlingen, 
near Tubingen, in Wurtemburg, the Posidonia schists of the 



BITUMINOUS STRATA OF HANOVER. 217 

Upper Lias have at times been worked for the manufacture of 
burning and lubricating oils and paraffin. 

The same schists have also been worked at Orawicza, in 
Hungary. 

By far the most important bituminous district in Germany 
is that of Hanover. This oil region extends from the city of 
Hanover, where oil is found in the suburb of Linmer, to the 
villages of Oilper and Klein Scheppenstett on the east and the 
Hildesheim Hills on the south ; and it has been thought pro- 
bable that the same condition of the strata may be found west- 
ward towards Bremen. 

The strata are apparently of Permian age, and it is possible 
that, in parts of the area, they may have connection with and 
be influenced by the overlying Eisleben shales in which the 
copper slate is found, and in which there is an abundance of 
fish remains and those of other sea organisms. 

The wells vary in thickness from 50 to 280 feet, according 
to the thickness of the strata overlying the oil-bearing beds. 
The general order of the strata is as follows, in descending 
order : 

Feet. 

1. Fine sand with boulders of granite and flint . 32 

2. Bluish grey clay 23 

3. Blue clay with layers of limestone ... 10 

4. Marl 65 to 80 

5. Rock with veins of quartz . . . .11510130 

6. Sandstone with pyrites, showing the first \ 

traces of oil Thickness 

7. Sandstone with black and red sand . . \ not 

8. Layer of pebbles, in which the oil is found given. 

most abundantly . ; . . / 

In the neighbourhood of Bentheim, to the west of Han- 
over, in sinking to the oil-bearing bed a deposit of bitumen 
has been found. This mineral is found solid in the fissures of 
the sandstone. About 400 tons of this bitumen have been 
raised here from a mine belonging to Mr. Sargent. This 
mineral, distilled at the mine, yielded no gallons of petroleum 
to the ton. 

This partially solid bitumen is frequently met with else- 



2l8 EARTHY AND OTHER MINERALS. 

where in the same position in sinking shafts. It varies in 
thickness from a few inches to 3 feet. Over the whole area 
bitumen is seen in places oozing out of the strata. 

As pumped out of the wells the liquid is composed of one- 
third water containing 2 per cent, of saline matter, and two- 
thirds oil. This crude oil, when refined, gives 45 per cent, of 
best petroleum. 

This oil region has been worked more or less for the last two 
hundred years. In the year 1872 Professor Harper, of Penn- 
sylvania, made a survey of the district, and during the last 
twenty years many trials have been made by boring. At the 
close of the year 1881 there were thirty companies formed, 
one hundred derricks already erected, and about sixty bore- 
holes in the course of sinking. At that time the average yield 
per well was from 10 to 15 barrels per day. An area of 
40 acres near Olheim, which, with Oilper and Oilberg, forms a 
great centre of the industry, yielded for a time from 400 to 500 
barrels a day. 

A great furore prevailed about this oil region, chiefly, it is 
to be feared, for speculative purposes, in the year 1882, and the 
proprietors of the land acquired an exaggerated notion of the 
value of their properties. They demanded from 6o/. to i5o/. 
per acre for the right of boring alone, with the necessity of the 
lessee purchasing one-half of the property as spoiled land. The 
agreements generally included the right to purchase the whole 
property within a given time. 

Some of these concessions were secured at a price of 137. 
per acre, and in parts more distant from proved oil wells the 
right to bore was secured at prices ranging from i/. to 8/. 
per acre. 

The wells were sunk by the Pennsylvanian rope boring 
apparatus at a rate of from 30 to 40 feet per day. 



219 



CHAPTER XIII. 
CA R BON continued. 

Bituminous Deposits of Spain, Italy, Roumania Bitumen and Petroleum 
of the Caucasus and Caspian Regions Bituminous Springs of the 
Valley of the Euphrates, of British Burmah, of the Punjab Pitch 
Lake of Trinidad Bituminous Springs of Barbadoes, Cuba, Venezuela 
Bituminous Coal Deposits of North America Geological Age of the 
various Petroleum-yielding Strata of North America Particulars of 
the Oil Mode of Sinking Wells Bituminous Springs and Schists of 
South America General Conclusions. 

BITUMINO US SUBSTANCES continued. 

IN SPAIN, at Maister, about ten miles east of Vittoria, there 
is an extensive layer of bituminous chalk, very fine-grained, 
compact, and regularly impregnated with bitumen. Unfortu- 
nately, it is situated at the bottom of an almost inaccessible 
gorge, but this natural difficulty will, no doubt, be overcome 
when the mineral is wanted. 

In ITALY, the oil of Agrigentum was famous in very ancient 
times, and in Piedmont crude oil has been pumped recently at 
Riva Nazzano, near Voghera, and also in the valley of Cocco. 
In Greece, a well in one of the Ionian Islands has yielded 
petroleum for upwards of two thousand years. 

Extensive beds of lignite occur in ROUMANIA, and bitumen 
is found in different localities. The latter mineral has been 
worked near Prahova and Bouzes, where amber is also found. 
In north-eastern Roumania there are numerous petroleum wells, 
and the oil-bearing strata are estimated to cover an area of 
about 856 square miles. The present annual production is 
computed as equal to about 300,000 barrels. 

The production of petroleum and other bituminous sub- 
stances is also large in Southern Russia, the productive strata 
between the Caucasus, the Caspian and Black Seas, being of 



220 EARTHY AND OTHER MINERALS. 

very great extent. Apart from the natural supply, utilised to 
some degree by the natives, latterly systematic attempts have 
been made to obtain petroleum by pumping. Two wells 
have been sunk in the valley of the river Kuban, which flows 
into the Black Sea, and many wells have been sunk in the dis- 
trict near Baku, on the Caspian Sea. These wells are generally 
sunk to a depth of 300 feet, and are said to produce 28,000 
barrels of crude petroleum. A large quantity of sand comes 
up with the oil. The refined oil is said to be equal to that of 
America. During the year 1882 the petroleum trade of this 
region was very much developed, and 5,000 vessels are said to 
have entered and left the port of Baku, which were chiefly 
employed in the petroleum trade. 

The production of refined petroleum for the year 1883 was 
206,000 tons, and the firm of Nobel Brothers manufacture in 
addition yearly 450,000 tons of mazoot, or liquid fuel, besides 
other products of petroleum. 

Reference has already been made to the abundance of 
bituminous matter on the banks and in the waters of the Eu- 
phrates, and we are familiar with the Bible reference to its use 
in the construction of Noah's ark and the building of the Tower 
of Babel. Evidence remains that it was used in the buildings 
of Nineveh, and to-day the springs of the region supply the 
inhabitants with oil. 

In India, petroleum, now usually known as Rangoon or 
Burmese oil, has from time immemorial been obtained from 
wells on the banks of the river Irawadi, on the north-east bor- 
der of Bengal, adjoining, and to some extent in, Burmah. These 
wells, of which there are usually from 500 to 600, are situated 
between Prome and Ava. The strata consist of marls of Green- 
sand age, which are interstratified with beds of lignite and bitu- 
minous matter, and these are overlaid by sand and gravel. The 
wells are sunk through these strata to a depth of about 200 feet, 
when petroleum is obtained, and also naphtha. 

The wells are mostly situated on the left or Burmah side 
of the river, which, near Wetmasut, forms a cliff several miles 
long and eighty feet high. Near Pugan, a little higher up the river 



THE PITCH LAKE OF TRINIDAD. 221 

than Wetmasut, there is interstratified a dark bituminous shaly 
limestone, which, from its fossils, is found to be identical in 
age with the London clay. Fossil wood abounds in the strata 
near Wetmasut. Along the whole length of the oil region be- 
tween Prome and Ava there crops up at intervals an older lime- 
stone, probably of Silurian age. The recent production of these 
wells is stated at 400,000 hogsheads, about 25,000,000 gallons. 

There are a number of springs in the Punjab, the yield of 
which, in 1880, was 2,850 gallons. 

In the WEST INDIES prominent notice must be given to 
the celebrated Pitch Lake of Trinidad. This forms the head 
of the harbour of La Brae. The bituminous matter, of the 
consistency of thick treacle, flows out of the hillside. It 
hardens on exposure to the atmosphere, but the newer streams 
flow over the older and more hardened layers. The surface 
of the hardened layers forms undulations in which are pools of 
water that contain fish. 

Beds of lignite and bituminous matter are interstratified in 
the cliffs of the shores, and the pitchy fluid oozes out and flows 
over the water as I have described. 

The hard bitumen is of a grey colour, rather brittle. It is 
varied somewhat in quality, as it is mixed with the sand and 
other matter over which it flows. 

It was from the bitumen of Trinidad that Dr. Gessner first 
obtained kerosene, and the result of several trials he made as 
to its oil-producing quality is as follows : 

Specific gravity ... 0-882 

Crude oil . ...... 70 galls, per ton. 

Refined oil . ... .42 

Lubricating oil ... . . II 

The strata appear to belong to the Upper Tertiary. 

Besides the Pitch Lake of Trinidad, the whole region con- 
tains springs of petroleum and bituminous matter. In St. 
Andrew's parish, Barbadoes, there is a petroleum spring, the 
product of which has been sold as 'Barbadoes tar,' or ' green tar.' 

Several springs issue from a serpentine rock at Guanabacoa, 
near Havana, from which different varieties of bitumen are 



222 EARTHY AND OTHER MINERALS. 

obtained. These were formerly used for pitching or ' careen- 
ing' the ships visiting the place. Near Cape de la Brea streams 
of naphtha issue from the mica slate and cover the sea for some 
distance. 

In the eastern part of Cuba, between Holguin and Mayan, 
there are also springs of petroleum. 

The same geological conditions prevail in VENEZUELA as 
in Trinidad, lignite and bituminous beds being interstratified 
with other beds of Pliocene age. Near the Rio Tara, on the 
surface of a sandbank, there are a number of cylindrical holes 
of different diameters, through which streams of petroleum 
mixed with hot water occasionally issue out with great noise, 
and to the extent of four gallons a minute. There are also 
places where inflammable gas escapes from the soil. In the 
neighbouring republic of Columbia, between Escuque and 
Belli] oque, bitumen is collected by the labourers, and by a 
rough process of distillation oil is obtained from it. 

NORTH AMERICA/ In describing the important bitumin- 
ous resources of North America, I will first notice some of the 
principal deposits of the more solid varieties of the mineral, 
and then describe the conditions under which the more liquid 
varieties of naphtha and petroleum are found. 

Among the first-named, the Albert coal, of Hillsborough, 
Albert County, New Brunswick, occupies a chief place. It is 
described as a vein nearly vertical, from one to sixteen feet in 
thickness, differing in several respects from an ordinary coal- 
seam. It is associated with rocks strongly impregnated with bitu- 
men, from which its contents have probably been derived. The 
mineral is brilliant in appearance, it breaks with a conchoidal 
fracture, and is highly elastic. It dissolves in naphtha and melts 
in the flame of a candle. Its composition is as follows : 
Carbon ...... 85-400 

Hydrogen 9-200 

Nitrogen . . . . . . 3-060 

Oxygen 2-220 

Ash -120 



100-0^0 



1 Hitchcock, Gessner. 



BITUMINOUS COALS OF NORTH AMERICA. 223 

The average yield of crude oil, as shown by several trials, 
is no gallons per ton, or 

Volatile matters .... 61-050 

Coke 30-650 

Hygroscopic moisture . . . 0-860 

Coke 7'44 

loo-ooo 

This mineral has been the subject of much litigation, hinging 
upon the question whether it was asphaltum or coal. Coal 
had been reserved by the Government, but no mention was 
made of asphaltum in the original grants of the land. In the 
spring of 1852, a Halifax jury decided that it was asphaltum, 
basing their decision on the scientific evidence laid before them. 
In the summer of the same year another jury, after a trial of 
eleven days, gave a verdict in favour of the mineral being coal. 
Perhaps, after all, it is only a vertical cannel coal seam. 

Breckenridge Coal. Among the coal beds of the vast Alle- 
ghany or Apalachian coal-field of the United States, there 
are several beds of cannel, including that which is known by 
the above name. This bed, which is a rich cannel, is worked 
in the county of Breckenridge, Kentucky. It is a bed of about 
three feet in thickness. It yields at a red heat 

Volatile matter ... . . . 61-300 

Fixed carbon 30-000 

Ash . . .... . 8-055 

Hygroscopic moisture . . -645 

Sulphur . . , . . trace 

100-000 

The results are, however, variable, as is the quality of the 
coal. Ordinarily it yields 130 gallons of crude oil to the ton, 
of which 58 to 60 may be made into lamp oil, with varying 
proportions of the heavier oils and of paraffin. 

Petroleum-bearing strata range over an immense area in 
North America, occupying large districts comprising several 
hundred thousand square miles, from Carolina in the south to 
Canada in the north, and from the extreme east to the ex- 



224 



EARTHY AND OTHER MINERALS. 



treme west. These strata are of almost every geological age, 
as the following particulars will show. 

Tertiary Strata. To the Pliocene division of this group 
belong the oil-producing rocks of California. In the Cretaceous 
strata of Colorado, Nevada, and the plains of the Mississippi 
River both petroleum and lignite beds occur. In North Caro- 
lina and along the Connecticut River oil occurs in beds of 
Triassic age. In Western Virginia the bulk of the oil wells 

are in strata that lie 
near the summit of 
the Coal - measures. 
Lower down in the 
same series, near the 
Pittsburgcoal, are the 
oil wells worked at 
Wheeling and 
Athens. Four hun- 
Rock and Shale, dred and seventy-five 
feet lower down still, 
near the Pomeroy 
coal-bed, is another 
oleiferous band; and 
again oil is derived 
from near the base of 
the Coal-measures in 
the top beds of the 
Millstone grit. The 
Archimedes lime- 
stone, which lies near 
the base of the Car- 
boniferous limestone, 
has produced oil in 
Kentucky. 

In the Chemang 
and Portage group, 
which corresponds to our Middle Devonian strata, are the 
petroleum wells of the West Pennsylvanian oil region, as well 




ist Sandstone, 
40 to 240 ft. 



Shales. 

2nd Sandstone, 
30 to 350 ft. 



Shales. 



Great Oil-bear- 
ing Sandstone, 
70 ft. thick. 



FIG. 54. SECTION OF OIL-BEARING STRATA ZN 
PENNSYLVANIA. 



PETROLEUM STRATA OF PENNSYLVANIA. 225 



as those in north-east Ohio. These strata have a combined 
thickness of from 2,000 to 2,500 feet. At the mouth of Oil 
Creek the lowest beds of the Coal-measures are seen capping 
the hills. The intervening rock between these and the upper- 
most strata of the valleys form the hillsides and the uppermost 
strata of the valleys. 

In these valleys the strata intimately connected with the 
oil-bearing rocks are shown in fig. 54. 

The average depth of the wells is about 650 feet, but wells 
have been sunk to a depth of 1,200 feet. The depth depends 
upon the amount of strata overlying the first sand rock at any 
particular point, and also, in a lesser degree, upon the variation 
in the thickness of the sandstones and shales down to the 
third sandstone. Oil is usually struck in the first sand rock, 
and it occurs more or less in the strata down to the third sand- 
stone, but it is in this rock that is the great oil-producing bed 
of the region. The 
separate beds of 
sandstone are readily 
distinguished by 
their enclosed fos- 
sils. 

These strata are 
throughout the re- 
gion thrown up in 
anticlinal ridges and 
synclinal troughs, as 
shown in fig. 55. 

The bulk of the 
productive oil wells 

have been sunk in the valleys, where the oil has accumulated 
in the troughs of the strata. But productive wells have also 
been worked in parts of the ridges where, in the process of 
upheaval, the strata have been broken, forming cracks of 
various magnitude. 

Authorities are divided in opinion as to the age of the 
Canadian oil strata, some making them the equivalent of our 

Q 




FIG. 55. SHOWING UNDULATIONS IN THE OIL STRATA 
OF PENNSYLVANIA. 

C, Base of Coal-measures, i, 2 and 3, Oil-bearing Sand- 
stone Rock. 4 4, Cracks occurring in the Anticlinal 
Ridges. 



226 EARTHY AND OTHER MINERALS. 

Wenlock limestone and shale, while others place them near the 
base of the Cambro or Lower Silurian. Possibly in different 
localities both of these groups of rocks contain pretroleum. 
One characteristic of the Canadian oil strata is the profusion 
of molluscan and crustacean remains they contain, and it is 
from these, as well as from the remains of other marine vege- 
tation associated with them, that the oil is supposed to have 
been derived. 

Some of the natural oil springs about Dereham and Ennis- 
killen occur along the line of a long, low anticlinal ridge 
which runs east and west, and is made up of a limestone with 
overlying shales. Springs also abound along the Thames for 
sixty miles west of Dereham. The oil seems to have been 
accumulated in the cavities of the limestone, and it is probably 
derived from the overlying shales with their vegetable and 
animal remains. In places the shales and the limestone are 
overlaid by drift ranging from forty to fifty feet in thickness. 
Productive oil wells have been sunk in similar strata in 
Kentucky and Ohio. Canadian petroleum was known to the 
early settlers, and on Black Creek pretroleum springs had 
covered about two acres of land. These have left solid 
bitumen on the surface, the lighter portions having evaporated. 

The quality of the oil varies according to the nature of the 
strata from which it is obtained, and, as in the great Penn- 
syivanian oil region, according to the depth from which it 
is worked. Heavy oils rich in the various ordinary products 
come from the shallow wells, the lightest oils coming from the 
greatest depths. 

The oil from the Pennsylvanian wells is of a greenish colour 
and in a crude state of an unpleasant smell. These oils yield 
when distilled 70 to 85 per cent, of a very fine burning oil, 
which is usually sold subject to the test that it will not inflame 
or pass into vapour under a temperature of 108 to 116. 

Some of the wells in Pennsylvania and some in Ohio give 
heavy oils of a dark amber colour which yields about 90 per 
cent, of petroleum and 5 per cent, of naphtha, and which is 
used in woollen manufacture instead of lard oil. Some of the 



MODE OF LETTING PETROLEUM LANDS. 227 

Ohio oils make excellent lubricators, and about Duck Creek 
fine burning oil of a light colour is obtained. 

Two tests of petroleum from California gave the following 

results : 



I. 



Burning oil ... 38 per cent. 

Lubricating oil . . 48 ,, 

Pitch ..... 10 ,, 

Water . 4 



2. 

Burning oil ... 50 per cent, 

Light lubricating oil 20 

Naphtha .... 5 

Heavy oil and paraffin 25 ,, 



Crude oil from the Buonaventure district in California give 
50 per cent, of burning oil and 28 per cent, of lubricating oiL 

The Canadian crude oil is of a dark colour and offensive 
smell, which was at first very much against its sale. With the 
improved methods of distillation now in use this smell may 
now be effectually removed. 

In the principal oil districts of the United States, on lands 
containing or supposed to contain oil, the right to raise the oil 
is usually leased by the owner for a period of thirty years. 
He reserves to himself a royalty ranging from one-tenth to 
one-half the oil, and he frequently receives at the outset a 
bonus of from i,ooo/. to 2,ooo/. The lessee is bound to 
commence work within two months, failing which he forfeits the 
lease, as he also does if he continues work beyond a specified 
time. Occasionally a lump sum is paid down for oil rights at 
the beginning. In Western Virginia this ranges from 40!. to 
2oo/. per acre. In the heart of the Pennsylvanian oil region 
the price is 2oo/. per acre. Further from the centres of the 
oil industry the price ranges as low as from 2o/. to 5o/. per 
acre. 

The wells are generally sunk with ordinary boring tackle 
worked under a square-framed derrick forty feet high. A pipe, 
usually 4 inches diameter, is first driven through the soil and 
jointed as it goes down, to a depth frequently of thirty feet. It 
is cleared of its contents of earth, clay, and sand by a suitable 
tool, and then the boring rods are put to work their way 
through the rock like the old-fashioned boring for coals in this 
country. Before the hole is deep enough the whole of the 



228 EARTHY AND OTHER MINERALS. 

boring tools usually weigh half a ton. When the hole has 
been taken down to the required depth, it is lined by a two- 
inch wrought-iron tube. In the first part of this tube that is 
let down the valves are carefully placed, and the first length of 
the pumping rods is attached. The remainder of the pipes are 
then screwed on in i2-feet lengths, and the pump rods attached 
as the tube is let down until the whole length reaches the 
bottom of the hole. 

The wells were sunk by this, the old arrangement, at the 
rate of six to eight feet a day, and the total cost of a well 
about sixty feet deep would be about zL $s. a foot. Drilling 
machines are now used with advantage as to the saving of 
time, but probably at not much less cost than formerly. 

Care is taken to prevent water flowing down to the pump 
by placing a bag containing linseed, so made as to encircle 
the tube at a given depth. The seed on becoming moist 
swells and fills the bore-hole, and effectually prevents the 
downflow of superficial water to the oil. 

SOUTH AMERICA. Bituminous schists occur near Mendoza, 
in the Argentine Republic, and liquid petroleum springs exist 
south of the city. An important deposit of petroleum also 
occurs about 200 miles from Mendoza on the road leading 
to the * Planchon ' Pass for Chili. The crude petroleum here 
yields 40 per cent, of pure kerosene oil. 

The liquid is discharged from fissures and other apertures 
in the rock. In the summer it flows more quickly and to a 
greater distance than in the winter. It gradually cools as it flows 
to a distance, and becomes a hard, compact mass of bitumen. 

From the foregoing description of the geological conditions 
under which bituminous substances occur in nature it will be 
seen 

i. That they are more or less connected with deposits ol 
vegetable matter, either forming part of such deposits, as in the 
case of cannel coal, the Boghead, Autun, Breckenridge, and 
other similar deposits, or derived from them, as in the case ol- 
the French and Swiss bituminous calcareous deposit, the 
Indian and American petroleum wells, and the Pitch Lake oi 



INFERENCES CONCERNING BITUMINOUS DEPOSITS. 229 

Trinidad, and the bituminous matter of the Caspian Sea and 
the regions of the Euphrates. 

2. Even where the original deposits of vegetable remains 
are not now seen overlying the bituminous matter, we may 
now assume, from slight indications that remain, as well as from 
the analogy of similar deposits elsewhere, that they once did 
and that they have probably been subsequently removed by 
denudation. 

3. We see that where bituminous matter abounds in a bed 
of vegetable remains, as in the cannels of Flintshire, the con- 
ditions under which such bed was originally formed were 
different from those under which ordinary coal beds were 
deposited. From the entire destruction of vegetable structure, 
and the presence above and below of fish remains, we infer 
that the vegetable matter of which bituminous coals were 
formed was deposited in water, and from the frequent issue 
of salt water from such deposits in salt water, probably in 
shallow lakes bordering upon the sea, and that they were 
composed of plants of different sizes and structure to those 
forming the less bituminous beds. 

4. We infer that so deposited in lagoons and marshy places, 
he juices of the plants themselves would escape evaporation, 

and also that in the process of decomposition the carbon of 
he vegetable matter would absorb and become chemically 

mixed with a portion of the hydrogen of the water by a similar 
)rocess to that we see occurring in hay, straw, and other sub- 
tances put together in a wet state, and partially excluded from 
he atmosphere, and in the course of which much heat is 
volved. 

5. As these deposits became covered up and compressed 
nto a completely solid state, and to the entire exclusion of 
ir and further moisture, their chemical condition became fixed, 
s we see in the case of coal-seams when first struck under- 
ground. 

6. When, consequent upon the breaking up of the strata by 
processes of upheaval and depression, air and moisture have 
been again admitted by cracks and by exposure in hillsides 



230 EARTHY AND OTHER MINERALS. 

and cliffs, chemical changes gradually follow, which of them- 
selves probably give off heat enough to cause a slow distilla- 
tion to take place. This result is illustrated in the issue of 
petroleum from the cannel coal-seams in the Buckley Mountain 
colliery, in the petroleum spring from the Shropshire coal 
seams at Madely, and in the flow of liquid bitumen at 
Trinidad. 

7. We are thus led to the conclusion that all the forms 
of liquid bitumen have been derived by a slow natural process 
of distillation at a low heat produced in the mass by chemical 
action ; that, favoured by natural fissures, the liquid has flown 
into cavities and natural receptacles in strata that are of older 
date than the source whence the liquid was derived. 

8. The chemical changes referred to have been accom- 
panied by a large production of inflammable gas, which in 
many of the American wells has been the chief agent in 
forcing the liquid volume to the surface. The water by which 
the oil is accompanied is that which has found its way from 
the surface, and derives its frequent saltness from the strata 
through which it has flowed. 

AMBER. 

Amber was called electron by the Greeks, because it 
became electric very readily when rubbed. It was also called 
succinum, or juice, from its supposed vegetable origin. 

Its chemical composition is: carbon 72^0, hydrogen io'5, 
oxygen 10*5. It is yellowish in colour, ranging to white and 
brown, and is transparent to translucent. It occurs in clays 
chiefly of Tertiary age in France ; in the London clay of the 
Paris basin ; in Austria on the coast of the Adriatic, and in 
Poland. It is most abundant on the German coast of the 
Baltic, in the peninsula of Samland, between the bays Tusche 
Haf and Kurische Haf, and especially near the town of 
Konisberg. It is imbedded in clay of Tertiary age, out of 
which it is washed by the sea where the clay is within the action 
of its waves, and it is collected on the sea-shore. It is also 
obtained direct from the clay by digging and subsequent washing 



AMBER DEPOSITS OF NORTH GERMANY. 231 

and sifting. The industry gives employment to about 1,400 
persons, and about 130 tons a year are collected. The right of 
gathering the deposits in the lagoons of Tusche Haf and 
Kurische Haf has just been let by the Prussian Government for 
a further term of twelve years to the firm which has enjoyed 
the monopoly for the last twenty-four years, for the sum of 
120,000 marks. It is estimated that each cubic foot of earth 
contains from half a pound to a pound of amber. Amber 
frequently contains the remains of insects which got entangled 
in it when it was A. viscous fluid, and many signs of their 
struggles to get free are apparent. The earth in which the 
amber is found seems to have been derived from the waste of 
Greensand beds, where these rested on an old Silurian rock, and 
it is supposed to have come into its present position by the 
wasting of such rocks in Scandinavia and Finland. 

The trees are such as grow in temperate zones camphor- 
trees, willows, beeches, birches, and oaks, with pines and firs, 
including the amber-pines. To have furnished the quantity of 
amber found it is supposed that many thousands of amber- 
pines must have perished and the amber gum have accumulated 
in the soil before the submergence of the land took place. 



232 



CHAPTER XIV. 
SULPHUR. 

Abundance of Sulphur in Nature Varieties Sulphur Mines of Sicily 
Situation Geological Position Details of Strata Thickness of Sul- 
phur Beds Percentage of Sulphur contained Associated Minerals 
Methods of Working, Costs Sulphur Mines of the Mainland of Italy 
Cessena Geological Position Thickness of Bed Modes of Work- 
ing and of the Treatment of the Mineral Sulphur Deposits of Greece, 
of Russia, of Iceland PYRITES, Production of in the British Isles 
Growth Of the Treatment of on the Tyne Pyrites of Norway, of 
Germany, of Spain and Portugal Description of the Rio Tinto Mines 
of Spain. 

SULPHUR is an abundant mineral in nature. In a finely dis- 
seminated form it is present in most rocks. It enters largely 
into the contents of mineral lodes. It is present in force in 
particular beds in different geological formations, and exten- 
sively associated with the ores of most metalliferous minerals 
silver, copper, tin, lead, zinc, iron, and many others. With iron 
and copper it is present in such abundance that the sulphuret 
of these ores forms one great source whence the sulphur of com- 
merce is derived. It also occurs native in the manner and 
under the conditions hereafter described. 

Native sulphur is in colour and streak yellow, sometimes 
of an orange yellow, with a resinous lustre, and transparent to 
translucent. It is soft, and may be scratched with the nail. The 
specific gravity is 2-07. It occurs perfectly pure and also 
mixed with clay, bituminous and other substances. When it 
contains selenium, it is of an orange yellow colour. It burns 
with a blue flame and a sulphur odour. It is a very useful 
mineral, being largely used in the manufacture of gun- 



SULPHUR DEPOSITS OF SICILY. 233 

powder, sulphuric acid, and for bleaching and medicinal 
purposes. 

The chief deposits of native sulphur are found in Italy. 
Indeed, up to the present time this country has possessed the 
almost exclusive monopoly of the production of sulphur, 
although there are lesser deposits of the mineral in France, 
Spain, Greece, and on the borders of the Red Sea. 

The chain of the Apennine Mountains, which runs down 
Italy and is continued into Sicily, is made up of Tertiary strata, 
and at various points along its course these strata furnish indi- 
cations of the mineral, which is to some extent mined. But the 
bulk of the sulphur produced by Italy is obtained from the 
deposits in Sicily, 1 the annual production being estimated at 
200,000 tons. The Government mining returns for 1881 
estimates the value of the whole of the sulphur mined in 
the kingdom at i,ooo,ooo/. In Sicily the central chain of 
mountains stretches from Messina on the east-north-east to 
Marsala on the west-south-west. Another chain crosses the 
island from Nito, on the south-east, and from the main chain 
about midway in its course opposite Cefalu. In the triangular 
space formed to the east of these two ranges rises the isolated 
volcanic mass of Etna. A little basin of strata containing 
sulphur is found to the north of the main chain in the province 
of Palermo. With this exception all the sulphur deposits of 
the island are found south of the main chain, and on both 
sides of the south-east and north-west chain, but chiefly on its 
west side. There are about twenty points at which the 
deposits have been proved and worked, the principal mines 
being situated near Cattolica, Girgenti, Licata, Caltanisetta, 
Centorbi, and Sommatino. 

Stratigraphically the sulphur deposits seem to belong to 
the middle of the Tertiary division of strata. The following is 
the general succession of these strata in the district, in des- 
cending order : 

1 <Les Mines de Soufre de Sicile,' par M. Ch. Lectorix, Annales des 
Mines , serie 7, tome 7. 



234 



EARTHY AND OTHER MINERALS. 



Pliocene. 



Upper 
Miocene. 



Middle 
Miocene. 



Lower 
Miocene. 



Eocene. 



1. Sandstone and calcareous cement, conglomerated sands 

with intercalated layers of fossiliferous marls and 
gypsum beds, thickness 100 to 150 metres. 

2. Calcareous tufa, chiefly made up of fossils in little accu- 

mulations, 100 metres. 

3. Bluish grey marls, 38 metres. 

*4. White calcareous marls with foraminifera, the colour 
sometimes being grey, 50 to 120 metres. 

*5. Saccharoid gypsum, crystalline gypsum, and foliated 
gypsum, with impressions of fish remains with sulphur 
beds, 20 metres. 

*6. Calcareous sulphurous marls, tufas, and gypsums, 35 

metres. 

7. Compact calcareous .marls, sometimes silicious, corres- 
ponding to the bed called cagnino in the sulphur 
mines of the Romagna, I to 30 metres. 

*8. Tripoli, divided sometimes by a deposit of calcareous 
and magnesian marl, thickness variable. 

9. Quartzose and micaceous sandstones with slightly saline 
marls and intercalated conglomerates, formed partly 
of fragments of crystalline rock and partly of ferru- 
ginous sandstones, 10 to 40 metres. 
/ 10. Deposits of salt crystals, generally missing where No. 9 

is present in force. 

II. Saliferous and gypsiferous marls of a bluish colour, 
containing petroleum and bituminous substances, 600 
to 1,000 metres. 
Calcareous concretions with silica, 15 metres. 

13. Ferruginous and gypsiferous clay with bituminous 

schists containing arragonite, 1,500 to 2,000 metres. 
This clay, over the northern part of the sulphurous 
zone, contains a limestone perforated by nummulites. 

14. Nummulitic limestone containing fucoids and jasper. 



/ 



*I2. 



The order of superposition given above is not very constant, 
some of the members of the series being frequently missing. 
Thus near Caltanisetta the silicious limestone and marls, No. 
7 is missing, while at the other parts, notably at Grotacula, 
Ries, and Sommatino, it is strongly developed. At Castel- 
ternrini also the gypsums, No. 5, are found both above and 
below the sulphur deposit No. 6. 

Of the foregoing strata, Nos. 4, 5, 6, 8 and 12 are those 
which contain the deposits of sulphur. 



SECTION OF SULPHUROUS STRATA. 



235 



The sections, figs. 56 and 57, show the particular grouping 
of the sulphurous strata near Caltanisetta and Sommatino, the 
section of the beds at the latter place showing also the highly 
disturbed nature of the strata a condition so prevalent that it 
is a local notion that highly inclined disturbed strata are the 
most productive of minerals. 

The sulphur occurs in the. beds in masses, lying in basin- 
shaped depressions in the sulphurous beds. These are sepa- 
rate from each other. They average in size 20 kilometres 
in length by 3 kilometres in breadth. The mineral is disse- 
minated in the mass of these basins in nests and in irregular 




FIG. 56. SECTION OF THE SULPHUROUS STRATA, NEAR CALTANISETTA, SICILY. 

a, Grits and Yellow Sands, b, Calcareous Tufa, c, Veins of bluish Clay, d, White 
Marls, foraminiferous. ef, Clays with Gypsum, g, White Marls with Fish Impres- 
sions, h, Sulphurous Clay, z, Grey Clay. S S, Sulphur Bed. 

branching veins, and in little beds lying parallel to the stratifi- 
cation ; exceptionally, as at Racalmuto, the sulphur lies in 
a sand dyke, cemented by both calcareous and bituminous 
matter. The sulphur is ordinarily amorphous, but it is met 
with frequently in flat, round, and oval-shaped masses that 
contain beautiful eight-sided crystals. Its ordinary colour is 
yellowish brown, with a resinous aspect. Sometimes it is 
yellow, with a slight tinge of green. There is also a soapy 
variety that is opaque and of an ochreous nature. The as- 
sociated minerals are sulphate of lime, carbonate of lime, and 
more rarely, sulphate of barytes. The deposits of sulphate of 
lime (gypsum), are in intimate relation to those of the sulphur, 



EARTHY AND OTHER MINERALS. 



and are apparently due to the same causes. This mineral is 
met with as a roof to the sulphur beds, and it also occurs in 
separate masses in the midst of them. It is also largely pre- 
sent in the marl beds, where it takes the name of balatino. 
The thickness and number of the sulphur beds or deposits in 
any one of the foregoing divisions is very variable. At the 




FIG. 57. SECTION EAST AND WEST THROUGH THE HILL SCORSONE, NEAR SOMMATINO, 

SICILY. 

A, Gypsum in large Crystals. A', Gypseous Marl. B, Tripoli Marls with Fish Impres- 
sions. C, Calcareous Marls and Limestones with Gypsum. D, Saliferous Clays with 
Salt Crystals. S, Sulphur Beds. 

mine Madore, near Lercara, the section is as follows, and 
the beds are called by the local names given : 



Metres. 



Metres. 



Bed. 

Zagareddada, ribbon-like deposits of 
sulphur 

Blackish schisty clay . . . 

Percullatella, nests of sulphur in lime- 
stone 

Clay 

Percullatella grandi . . . . 

Clay 

Orlando 



or giving from 1 6 to 22 metres of sulphur. 

At Caltanisetta the average thickness is 4 metres. At 
Grotacula 12 metres in three deposits, which are separated 
by clay of from i to i metres thick. At the great mine of 
Sommatino the thickness reaches 30 to 33 metres, and the 
deposit is divided into six parts of from 2 to 8 metres, which 
are separated from each other by barren partings of about i 



8 

i 

2 
2 

4 
5 
5 


o 
5 



o 
o 





o 




o 
o 
o 

o 


to 

> 


2 

4 
6 

6 

6 




5 

o 
o 





o 

O 


o 

O 





MINERALS ASSOCIATED WITH SULPHUR. 237 

metre thick. At Lercara the deposit reaches a thickness of 
33 metres without any barren partings at all. 

The minimum thickness of the beds is from i to 2 metres. 
They are extremely disturbed, inclined, and distorted, and thus 
different portions of the same deposits are separated from each 
other. 

The percentage of sulphur contained in the mass of the 
deposits is also very variable. At Madore it is 20 per cent. ; 
at Grotacalda, 25 to 27 ; -at Sommatino, from 18 to 26 ; 
at Cimico, near Racalmuto, 21. In some mines it is as low 
as 12 per cent. Sometimes near the surface hydrogen is in- 
timately mixed with the sulphur, and this is considered a 
good indication. When this sulphur is exposed to the air it 
decomposes, and becomes similar to the soapy sulphur that is 
found elsewhere in the deposits. 

The underlying clays or marls are nearly always bituminous, 
and occasionally, as at Racalmuto, the sulphur itself is im- 
pregnated with bitumen. Hydro-carbon emanations are still 
continued, and are noticeable at many points, more particularly 
near Caltanisetta and Girgenti, where there is volcanic mud, 
salt water, and hydro-carbon emissions. 

It has been assumed that these sulphur deposits were 
formed in a series of lakes or lagoons, containing fresh or 
brackish water, into which sulphate of lime found its way, 
the sulphur being thrown down by volcanic emanations, and 
the organic matter permeating the mass of the underlying clays. 

Associated with the sulphur deposits, or contiguous to them 
are those of saltpetre, chloride of potassium, chloride of 
magnesia, and sulphate of soda. The range of the salt deposits 
commences to the south of Nicosia, and extends to near 
Cattolica. The greatest breadth of this saline band is about 
20, and its length 120, kilometres. The salines do not con- 
stitute a continuous deposit over all this area, but they are 
concentrated in different groups, the most important of which 
are those of Leonforti, Priolo, Cranara, and Trabona, between 
Caltanisetta and Marianopolis. In these deposits there are 
also the chlorides of soda and magnesia. 



238 EARTHY AND OTHER MINERALS. 

The working of the Sicilian sulphur mines is for the most 
part in a very crude state. Until recently the miners were 
ignorant of the use of vertical shafts and of the use of timber 
for supporting roofs. They knew little or nothing of a plan, 
nor of any engines, machines, or mechanical appliances for 
the extraction of the minerals or the drainage of the mines. 
This state of things has resulted from the absence of mining 
legislation, from the profound ignorance of the people, the 
isolation in which they always live, the want of communication 
into the interior of the country, the want of fuel, vegetable or 
mineral, and the scarcity of wood for mining purposes. 

Of late years strangers have embarked in mining operations 
on the island, and they have endeavoured to introduce 
improved methods of mining. But they have met with great 
opposition from the lack of resources in the country itself, and 
also, and most of all, from the opposition, latent and open, of 
the people of the country. This resistance, organised in secret, 
finds means of manifesting itself against modern innovations 
that arouse their antipathies. The consequence is that it is 
computed that at nearly all the three hundred and fifty mineral 
works not more than a quarter of the work is done that ought 
to be done for the money expended. In the mines worked by 
strangers a change for the better is apparent, and, with the 
extension of railways, the development of instruction, and the 
efforts the Italian Government is making to repress crimes of 
violence, and in the deepening of mines, which render the 
ancient methods of working useless, there are signs of improve- 
ment, but it is felt that the progress is slow, and the full 
improvement desired will not come yet. 

When the bed of sulphur crops to the surface itself, and the 
inclination is not more than 45 degrees, a descent is made in 
the bed itself. If the sulphur itself does not crop up to day, but 
the buscale or containing bed is there, or the patches of sulphur 
in the wall of limestone (calcare du mur), or the soapy sulphur 
presents itself, a tentative or inclined shaft (bud or scalier), which 
is designed so as to reach the deposit in the shortest distance 
possible, is made. This is also done when the inclination is 



MODE OF WORKING THE SICILIAN SULPHUR MINE. 239 

more than 45 degrees. These inclined galleries are provided 
with simple ladders when their slope is from 30 degrees to 35 
degrees. When the slope is more than this, two sets of ladders 
are placed side by side, and they are so arranged that the 
landing-place of the one is half way up the other. 

The mineral is carried up these ladders on the backs of chil- 
dren and young people of from eight to eighteen years of age, 
called careizi, the weights ranging from 20 Ibs. to 80 Ibs., accord- 
ing to the age and strength of the bearer. They carry the big 
lumps directly on their shoulders. The small is carried in 
sacks made of rushes. It is not without danger that these long 
files of careizi race up and down the bud and ladders. Some- 
times one of them lets fall his burden, to the hurt and discom- 
fiture of those below. 

When a little water is met with, it is drawn with bottles of 
baked earth that hold from 16 to 20 litres, and these are passed 
from hand to hand upwards. When the inflow of water is con- 
siderable the work is abandoned. A new one is usually com- 
menced by the side of the old one, which usually meets with 
the same difficulties and fate, the workers only winning the 
sulphur that lies above the water-line. 

The bud, or inclined shafts, when made in the gypsum or 
limestone, usually stand without timber, but when they traverse 
the marls they are maintained by a casing of stones cemented 
in plaster, which plaster is baked at a low temperature obtained 
by burning straw. The plaster sets rapidly, but on exposure 
to the atmosphere it falls to pieces and needs constant repairs. 
In the mining excavations in humid marls this casing is quite 
insufficient, and the whole work collapses and is abandoned. 

When the bud reaches the deposit a number of openings 
are made in the latter, usually without any method except that 
of following the rich mineral, and leaving pillars to support the 
roof. The roof being usually of clay, a thickness of about a 
yard of the sulphur is left to support, and when the chambers 
are very large the sides are strengthened by walling, as already 
described. The mineral is extracted by a pick with a blunt 
point; powder is seldom used, especially in the rich mineral, its 



240 EARTHY AND OTHER MINERALS. 

use being attended with danger. The pick-men make six 
hours actual work in the mine per day, and each man is sup- 
posed to extract about one ton. The men receive from two to 
three lire a day.- The price paid for extraction depends a 
good deal upon the depth of the mine, the thickness of the bed, 
and the hardness of the enclosing rock. At the Madore mine, 
which is of an average depth of 45 metres, the price is 13 lire 
per cubic metre. At Raculmuto, with a depth of 65 metres, it 
is about 15 lire. 

At the Madore mine the cost of a ton of ore is estimated as 
follows : 

Lire. 

Breaking down . . . , . . 1*57 

Subterranean and shaft carriage . . . . 2*04 

Lights, tools, and repairs . . . . . "37 

Putting on heap at surface -25 

Keeping up the mine and works . : . . -42 

Drainage . . . . . '. . .' '4 2 

Superintendence and general expenses . . . -90 

579 

At the mines of Cornica the cost per ton is estimated at 
5- 1 2. The average cost per ton is given at 5-38. To this sum 
has to be added the cost of general administration, taxes, 
redemption of capital, &c. = i*i4, making a total cost per ton 
of 6-52. 

We will take as an example of the sulphur mines worked 
on the mainland of Italy those grouped near the ancient epis- 
copal town of Cessena, and which are worked with English 
capital and skill. These mines comprise several properties 
the Boradella, the Ca di Guido, the Borella Tarna, the 
Polenta, and the Monte Codruzzo. These properties are 
situated on the slopes of the sub-Apennine chain of mountains. 
As in Sicily, the enclosing strata belong to the Miocene divi- 
sion of the Tertiary strata. The sulphur deposits occur in 
marls that contain a good deal of sulphate and carbonate of 
lime. The chief bed worked is from nine to twelve feet thick, 
and with the enclosing strata forms a shallow basin-shaped 



THE SULPHUR MINES OF CESSENA, ITALY. 241 

deposit. The mineral contains 22 per cent, of pure sulphur, 
the ore occurring in ribbon-like strings and masses of varying 
sizes. 

The mineral is won by shafts, of which there are a good 
many. These are sunk to the marl that underlies the sulphur, 
one of them attaining the depth of 1,100 feet. From the bot- 
tom of the shafts levels are driven and galleries opened out in 
the deposit, pillars being left to support the roof. Not without 
considerable opposition the principal shaft has been furnished 
with modern pit-gear, and with guides and cages, all of which 
created serious consternation when they were first introduced. 

When the sulphur mineral is brought to the surface it is 
placed in large circular kilns, like lime-kilns. Of these there 
are fifty-five conveniently placed in relation to the shafts ; each 
kiln will hold 350 tons of mineral at one charge. When full the 
mineral is ignited, the burning sulphur furnishing the greater 
part of the heat required for treating itself. The brimstone 
falls into the basin at the bottom of the kiln, from which, at 
stated periods, it is run into blocks of brick-coloured sulphur 
called black sulphur. In the process of calcination a loss, 
estimated at 35 per cent., is sustained, owing to the escape of 
the portion ignited as sulphurous acid. Experiments are being 
made, with only a limited success hitherto, to prevent this loss. 

The total cost of mining the ore, calcining and producing 
the black sulphur, is given at 3/. per ton, inclusive of delivery. 
The selling price is 5/. $s., showing a profit of 2/. 5^. But it is 
probable that when all outside and exploratory charges are 
provided for the cost will be considerably increased. 

About one-seventh of the produce of the mines is sold as 
black sulphur; the rest is converted into pure sulphur by 
sublimation and condensation in iron retorts. During this 
refining process a further loss of about 3 per cent, is sustained. 
The refined sulphur sells on the spot for about 6/. 2s. 6d. per 
ton, the profit being estimated at i/. i$s. to i/. 17^. 6d. per ton. 
The mines are worked on the pillar and stall system. The 
difficulties to be contended with are the swelling of the strata, 
as in a coal mine, falls of roof, barren ground, and fires. A 

R 



242 EARTHY AND OTHER MINERALS. 

very disastrous fire occurred in the old workings in 1872. A 
few years since the annual production of sulphur from these 
mines was about 12,000 tons. 

GREECE. The sulphur deposits of Greece occur about three 
miles east of the Isthmus of Corinth, and they lie in a series of 
cream-coloured and grey gypseous marls that underlie a white 
Miocene limestone. They therefore occupy the same strati- 
graphical position and occur in similar mineralogical associ- 
ations to those of Sicily. The limestone ridges rise to a height 
of 2,000 feet on the northern shore of the Sea of ^Egina, and 
show a disturbed condition of the strata. They are broken by 
rocky gorges and fissures. At a height of about 250 feet above 
the sea the marls are loaded with sulphur. On entering these 
gorges and the caverns and fissures by which they are traversed, 
the temperature is found to be about 100; large bodies ot 
stifling vapours are emitted, and great heat is discernible on 
the floor of sulphur, the whole seeming to indicate a present 
connection with volcanic heat. The caverns are completely 
lined with crystals of sulphur and other minerals. The sulphur 
beds extend for several miles, and are traceable for half a mile 
in width. The fissures run nearly north and south, and they 
seem to be connected with disturbances which have taken place 
at a comparatively recent period. The sulphur occurs in small 
globular masses in the gypseous beds, and also in a crystalline 
form, especially near the fissures from which the heated gas 
issues. These deposits have not been largely worked hitherto, 
and little or nothing is known about the exploration and pro- 
duction of the sulphur. 

RUSSIA. Although not of commercial importance, the sul- 
phur springs at the Imperial baths of Sergiefsh, on the banks of 
the river Sok, a tributary of the Lower Volga, are interesting as 
throwing light upon the formation of the deposits we have 
already noticed. A considerable volume of gaseous sulphurous 
water issues from Permian limestones and marls, which also 
contain bitumen and gypsum, and forms a large pool in which 
the different substances are deposited with some amount of 
separation and distinctness. 



THE SULPHUR SPRINGS OF ICELAND. 243 

ICELAND. Still more interesting for the same reasons are the 
sulphur springs of Iceland. These are situated in a rather vol- 
canic district near Reykjalid, in the north of the island. A 
series of them occur along a bare mountain-ridge covered with 
deep loose sand of a reddish colour, near the lake Myvatn. 
The sulphur springs are of two kinds, which are, however, 
intimately connected with each other : first the actual sulphur 
springs, ' solfataras,' which consist of hot gaseous exhalations 
from the earth, which deposit sulphur. These may be called 
the dry springs. The others are the mud springs or 'makka- 
luber.' They are boiling springs filled with muddy water of a 
dark colour, owing to the presence of sulphate of iron. The 
first-named are on the slope of the mountain ; the last are at 
its foot, on the edge of a plain that stretches away to lava plains 
beyond. The first, the solfataras, occur separately and grouped 
in small numbers ; they are characterised by a small flat eleva- 
tion, from the centre of which the gaseous matter is ejected 
through one or more openings, which are seldom more than 
half an inch in diameter. The gaseous matters consist of sul- 
phuric acid, hydrogen, sulphurous and aqueous vapour. Usually 
they issue quietly, and they are partially condensed in the air, 
and carried about in the form of a white vapour which seriously 
affects the respiratory organs. Occasionally the gas issues 
forth with great violence and with a loud hissing noise. On 
the surface these solfataras are covered with loose blown sand 
like the rest of the ground, but underneath this there is a crust 
of bright yellow and nearly pure sulphur, which is that taken 
for exportation. Underneath this, the other products of the 
vapours are found in pure clay, gypsum, and ferruginous clay in 
separate layers. 

The ' makkaluber,' of which there are seven or eight large 
ones, have cauldron-shaped openings, eight to twelve feet in 
diameter ; these are filled with boiling black mud, which is 
thrown up on the edges of the cauldron. The chemical processes 
that take place in these ' makkaluber ' and solfataras are the 
same. From the former there is no deposit of sulphur on the 
surface, but underneath, at no great distance, there is a trea- 



244 EARTHY AND OTHER MINERALS. 

cherous deposit of boiling black sulphurous clay. One of these, 
near the lake Myvatn, is 300 feet in circumference, and is a 
lake of boiling mud, with many jets scattered over its surface. 

The region of sulphur springs extends in a south-westerly 
direction from those of -Reykjalid and Myvatn to Krisnvik, in 
the south-west of the island. Here, as in the north, in the 
neighbourhood of the mud springs there is usually a bed from 
one to three feet deep of pure sulphur, resulting from the de- 
composition of the gases escaping from the earth on their coming 
into contact with the atmosphere. Mr. C. S. Forbes, in his 
Iceland, her Volcanoes and Glaciers, in describing a sulphur 
spring of this locality, says : * In the valley beyond, about 
fifty feet beneath us, lay a huge cauldron, twelve feet in dia- 
meter, in full blast, brimming and seething with boiling blue 
mud that spluttered up in occasional jets five or six feet in 
height, diffusing clouds of vapour in every direction. If a con- 
stant calm prevailed here, instead of ever-varying gales, the 
sulphur sublimated from these sources would be precipitated 
in regular banks ; as it is, it hardly ever falls twenty-four hours 
in the same direction, the wind blowing it hither and thither, 
capriciously distributing the sulphur shower in every quarter. 

' Such, with little variation, save in locality, were the nu- 
merous soufrieres and solfataras that we visited, and they 
extend over a space of twenty -five miles in extent. The riches 
of the district consist not so much in these numerous crusts of 
almost pure sulphur as in the beds of what I must be permitted 
to term sulphur earth, which are promiscuously scattered in all 
directions, ranging from six inches to three feet in thickness, 
and containing from 50 to 60 per cent, of pure sulphur.' 

The sulphur deposits of Iceland are hardly thick or exten- 
sive enough to be commercially valuable, especially as the 
sulphur when obtained has to be carried a two days' journey 
on horseback to a trading station, where the price obtained for 
it is seldom more than 3^. per hundredweight. Hence it is 
that sulphur works which have been established at different 
times in the island have usually come to an unsuccessful end. 

Springs containing sulphur, from those whose water is 



PYRITES DEPOSITS OF BRITAIN. 245 

taken medicinally to those more nearly approaching the mud 
springs in Iceland, are found in nearly all countries, and in 
strata of various ages. Some of these we have had occasion 
to refer to in describing the salt deposits. 

PYRITES. 

In the chapters on arsenic, cobalt, and other minerals 
referred to in this work, as well as in the chapters relating 
to copper and iron, in a former volume, 1 I have noticed in 
detail the composition of those mixtures of sulphur with iron 
and with copper, and of those with arsenic, cobalt, and anti- 
mony, which are known by the general name of pyrites. I 
have now to notice the mineral more particularly as a source 
whence a portion of the sulphur of commerce is derived, and 
as the chief mineral now used in the manufacture of sulphuric 
acid, iron pyrites, the general composition of which is : iron 
46*7, sulphur 53*3. It is, however, frequently mixed with small 
quantities of copper, arsenic, and minute quantities of gold. 

BRITISH ISLANDS. The production of iron pyrites in these 
islands in the year 1881 amounted to 43,616 tons, of the esti- 
mated value of 30,0337. Of this quantity, about 15,000 tons 
were derived from the Coal-measures, in the strata of which they 
are known as ' brasses.' The rest were from the older strata 
of Cornwall, Wales, and Ireland. The production of the 
copper mines of Cornwall and Devon amounted to 16,000 
tons, and the bulk of these were treated for sulphur and for 
arsenic, in the manner to be described, at the works in those 
counties. Wales, from the older rocks, produced 3,679 tons, 
of which one-half came from the Cae Coch mine, near Trefrhiw, 
in Carnarvonshire, a region whose strata, slates included, are 
black v/ith decomposed iron pyrites. Ireland, from four mines 
in counties Clare and Wicklow, from Cambrian or Silurian 
strata, yielded 8,598 tons, the bulk of which came from the 
Tigrony mine in County Clare. But the imports of pyrites 
from abroad far exceed the native production of the mineral, 
and the growth of the pyrites trade, and the treatment of the 

1 Metalliferous Minerals and Mining. Crosby Lockwood & Co. 



246 EARTHY AND OTHER MINERALS. 

mineral on the Tyne, the chief seat of the industry, are the 
most remarkable developments of modern times. 

In the year 1810, Messrs. Doubleday and Easterby erected 
the first sulphuric acid chamber on the Tyne at Bell Quay. 
They obtained the plans of the chambers from the Messrs. 
Tennant of Glasgow, at which place, and at Amlwch, near the 
Mona and Parys copper mines, the manufacture had been 
carried on, to a small extent, previously. They imported the 
first cargo of sulphur from Sicily about the same time, and its 
arrival in the Tyne is described as having excited great atten- 
tion. On the Sicilian sulphur there was then an excise duty 
of 1 5/. per ton, but this amount was remitted to the firm by the 
Government. In the year 1825 the duty was reduced to los. 
per ton, the cost of the ore delivered in the Tyne being from 
6/. to 8/. per ton. In the year 1838 the King of Sicily granted 
a monopoly of all the sulphur raised in his dominions to 
Messrs. Faix & Co., of Marseilles. This proceeding led the 
chemists of this country to turn their attention to the use of 
pyrites as a substitute for sulphur. For fifteen or sixteen years 
the British Islands furnished all the pyrites that were required, 
but in the year 1856 attention began to be turned to the impor- 
tation of pyrites from Belgium, Norway, Westphalia, in Germany, 
and from Spain. It was also found that the pyrites from Spain 
were the richest in sulphur, and from that time they have been 
increasingly used. The total importation of pyrites iron and 
copper by this country in the year 1881 was 542,378 tons, of 
the value of i,202,28i/., this quantity also being about the 
average quantity imported yearly for the preceding ten years. 
From these pyrites there were, in 1881, obtained, besides the 
sulphur and sulphurous products, 14,000 tons of copper, 
258,463 ounces of silver, and 1,490 ounces of gold. Of the 
pyrites imported, 173,978 tons were received into the Tyne, 
204,163 tons in the Mersey, to be used at the works grouped 
about Widness and Runcorn ; the rest was distributed among 
the ports of London, Hull, Bristol, Cardiff, Swansea, Ardrossan, 
Glasgow, and some minor ports. We have not the particulars 
oi quantities from the different countries exporting to us for the 



PYRITES DEPOSITS OF NORWAY AND SPAIN. 247 




FIG. 58. SECTION OF CUPREOUS 
PYRITES IN RANENFJORD, NORWAY. 

I, Pyrites Deposit, 30 to 40 ft. thick. 
22, Hornblende Schists. 33, Mica 
Schists. 



year 1881, but in the previous year, when the total quantity 

amounted 10658,047 tons, Spain 

sent 463,199 tons, Portugal 

166,519 tons, Norway 10,952 

tons, Germany 8,695 tons, and 

other countries 8,684 tons. 

The pyrites from Norway are 
obtained along the west coast, at 
the mines of Ysteroen and Vog- 
naes. Farther north, a deposit is 
just now being opened near Mo, 
in Ranenfjord, which will serve 
as an illustration of the usual 
mode of the occurrence of great 
masses of pyrites in that country. 
Fig. 58 will illustrate this. 

The German pyrites are ob- 
tained from mines to the east of 
the Rhine, between Cologne and Coblentz, and from the mines 
of the Hartz, and which are 
treated on the spot. 

SPAIN AND PORTUGAL. 
It will be seen that the 
bulk of the pyrites now used 
in Great Britain comes from 
these countries. The prin- 
cipal district from which the 
mineral is obtained is the 
rich mineral region situated 
on each side of the boun- 
dary line between the two 
countries, shown upon the 
map (fig. 72), as that line 
comes down to the south 
of the two countries, be- 
tween Cape St. Vincent on 
the west, and the Straits of Gibraltar on the east. As described 




FIG. 59. SECTION OF PYRITES DEPOSIT, HUELVA, 

SPAIN. 

A A, Fahlband. B, Decomposed Clay Slate. 
C and D, Greenstone. 



248 EARTHY AND OTHER MINERALS. 

in the chapter on manganese, the rocks of the district consist of 
slaty schistoze strata of the Lower Silurian group. These are 
interstratified with greenstone and felspathic rocks of various 
kinds. The general direction of the strata is from north-east 
to south-west, with a dip of 40 to 50 degrees, and in the vicinity 
of the pyrites deposits up to 70 degrees, to the south-east. The 
pyrites occur in the line of bedding, and usually resting upon, 
as its lower stratum, a greenstone or felspathic rock. Fig. 59 
will illustrate their usual mode of occurrence. 

The pyrites deposits are not continuous, either vertically or 
horizontally. They occur in lenticular-shaped masses, extend- 
ing in length to 450 yards, in depth 90 yards, and in breadth 
125 yards, this being the present size of the great open cast 
worked on the south lode of the Rio Tinto mines. The pro- 
portion of sulphur in the mineral is about 48 per cent. Copper 
is present up to 3 per cent , and there is also a small quantity 
of gold and silver. The district was worked by the Phoeni- 
cians and Romans. The red colour of the river Rio Tinto 
indicating the presence of mineral, subsequently and at inter- 
vals the mines were worked by the Government of the country. 
Ten years ago, when an English company took over the Rio 
Tinto mines from the Government, the production was 50,000 
tons a year, and the mines were worked at a loss. There are 
three great companies now at work in the immediate neigh- 
bourhood the Tharsis, Mason & Barry, and the Rio Tinto 
with one or two others of scarcely less importance. A glance 
at the operations of the last-named company will show the 
magnitude and immense resources of the mines. There are 
three chief lodes or deposits on the property the south, 
San Dionisio, and the north. It is on the first of these 
that the workings have been most extensive. The great open 
cast excavation mentioned above is on this deposit, and from 
500,000 to 600,000 tons of ore are annually taken from this 
excavation. There are underground workings on the same 
lode below the open cast, and from these 320,000 tons of ore 
were taken in 1881. These workings are reached by a tunnel 
driven on the lode some 500 yards in length, and this is now 



THE RIO TINTO PYRITES MINE. 



249 




250 EARTHY AND OTHER MINERALS. 

being connected with the San Dionisio lode, which it will open 
up. On reaching the principal shaft, which has been sunk on 
this lode, the tunnel will be two miles and a-half in length, of 
which a mile and a-half will be in solid mineral. Three shafts 
the Albert, Edward, and Alice have been sunk upon this 
lode. The operations upon the north lode are more recent, 
but about 700 yards of tunnel have been driven upon it, nearly 
300 of which are in mineral. In uncovering the great open 
cast upon the south lode, nearly three and a-half million tons of 
earth and other over-burden were removed before the ore- 
deposit could be worked. The ore raised and disposed of in 
1881 was 1,000,000 tons, of which 230,000 tons were shipped 
to England and other countries, 50,000 tons were left in store 
at Huelva, and the remainder was treated at the mines for the 
production of copper, of which 10,000 tons were produced and 
sent to England. There are about six miles of precipitating 
tanks, and 15,000 to 20,000 tons of pig-iron are annually used 
in effecting the precipitation of the copper. Ten thousand 
five hundred people are employed by the company at the mines, 
on the railway, and at the port of Huelva. There are forty 
miles of railway about the mines, which are also connected 
with the port of Huelva by a railway eighty-three kilometres 
long, which winds down the valley of the Rio Tinto. The 
other two companies are in very successful work, and their 
production and export of ore, although not so great as that of 
the Rio Tinto, is still very large. Fig. 60, from a photograph 
by Mr. Thwaite, of Commercial Road, London, S.E., and 
kindly given me for use in this book, will afford an idea of the 
extent, importance and varied nature of the works at the Rio 
Tinto Mines. 

In the year 1882 theTharsis mines shipped 212,218 tons of 
pyrites, 5,534 tons of precipitate, and 184,059 tons of iron ore. 
The year's operations yielded a profit of 335,6767., of which 
314,4797. was distributed in dividends, equal to 27! per cent. 
on the paid-up capital. 



PART IV. 

METALLIC MINERALS, 

ARSENIC, COBALT, MOLYBDENUM, ANTIMONY, 
AND MANGANESE. 



(OF WHICH THE METAL IS RAPIDLY OXIDISABLE, AND 
HAS HITHERTO BEEN EXTRACTED WITH DIFFICULTY.) 



: 53 



CHAPTER XV. 
ARSENIC. 

Arsenic, Native Orpiment, Realgar, Mispickel Production of Arsenic 
in the British Islands Mode of Treating the Ores in Cornwall and 
Devon, and in Bohemia Mispickel of Norway and Sweden, of 
France, of Germany, of Austria, Transylvania, and Hungary, of 
Russia, Spain, Turkey, China, and of North and South America. 

ARSENIC occurs native, in combination with oxygen, as white 
arsenic or arsenous acid, united with sulphur in its two sul- 
phurets, Orpiment, or yellow sulphuret, and Realgar, or red 
sulphuret. Also, in combination with sulphur and iron, as 
Mispickel, or arsenical pyrites. It is also largely combined, 
as we have seen, with other minerals lead, manganese, nickel, 
silver, and cobalt, as well as with lime, as arsenate of lime. 
Arsenic burns with a bluish flame, and in all the forms in which 
it is found it may be unmistakably known by the white fumes 
and the pungent garlic smell it gives off when heated. 

NATIVE ARSENIC is found in massive, granular columns, 
and in rhombohedral crystals. In colour it is tin white, light 
lead grey, and tarnishing to greyish black. Its specific gravity 
is from 5*65 to 5*75, but when artificially prepared the gravity 
is described as greater. It is of a very brittle and friable nature, 
and is easily pulverised. When freshly fractured it has a 
brilliant appearance, but it soon oxidises on exposure to the 
air. The fracture is granulated, and sometimes a little foliated 
and splintery. It rises in vapour at 356, without undergoing 
fusion, and burns with a pale bluish flame when heated just 
below redness. It occurs in connection with silver and lead 
ores. 



254 EARTHY AND OTHER MINERALS. 

WHITE ARSENIC (Arsenous Acid}. This is the same sub- 
stance as the arsenic sold in the shops, and it is a well-known 
poison. Chemical composition: arsenic 75-8, oxygen 24-2. 
Specific gravity 37. It is white in colour, astringent, and 
sweetish in taste, and soluble in water. 

SULPHURET OF ARSENIC occurs in two forms : 

1. Orpiment, or Yellow Sulphur et of Arsenic. This occurs 
massive, also disseminated and crystallised in oblique four- 
sided prisms. The crystals are small, with a smooth surface, 
and are irregularly clustered together. Colour, fine golden 
yellow, with brilliant pearly or metallic lustre on the face of the 
cleavage. Specific gravity 3*3 to 3*5. Chemical composition : 
arsenic 6ro, sulphur 39*0, but different tests have shown 
a range of from 57*0 arsenic, and sulphur 43*0, to arsenic 84-0 
and sulphur 16. 

2. Realgar, or Red Sulphur et of Arsenic. Also occurs in 
oblique four-sided prisms, and, but more rarely, in a massive 
form. The colour ranges light aurora red, scarlet red, and 
orange yellow, with a resinous, translucent, or transparent lustre. 
Specific gravity 3 '35 to 3*65. Chemical composition: arsenic 
70, sulphur 30, but these proportions are varied by small 
quantities of iron and silica. Both of these sulphurets burn 
with a blue flame on charcoal, and evaporate entirely before 
the blow-pipe with a strong garlic odour. The foregoing ores 
are soft, being easily scratched with the finger nail. 

MISPICKEL (Arsenical Iron Pyrites). Occurs massive and in 
long rhombic prisms, silver-white colour, with a grey or yel- 
lowish tarnish, and a black streak. Chemical composition : 
arsenic 46*0, sulphur 19*6, and iron 34*4. These propor- 
tions are varied by small quantities of silver and gold, and with 
cobalt up to 9 per cent. This mineral forms the source whence 
a large quantity of the arsenic of commerce is derived. 

Arsenic is largely used in the arts and manufactures. Be- 
sides its use as a poison, white arsenic is used as a flux in the 
making of glass, and also to give a porcelain-like appearance 
to the same article. The sulphurets are extensively used for 
colouring purposes, and attention has often been drawn to the 



PRODUCTION OF ARSENIC IN BRITAIN. 255 

danger, real or supposed, arising from their use in the colouring 
of wall-paper. The colour known as King's yellow is made 
from orpiment, and an ammoniacal solution of the same is used 
for dyeing. Realgar is used in the manufacture of fireworks, 
more especially for the production of the flame known as white 
Indian fire. A combination of white arsenic with oxide of 
copper produces the fine green colour known as Scheele's 
green. It is also used in the proportion of i per cent, with 
lead in the manufacture of shot. Its presence causes the molten 
lead to separate more easily into drops as it is poured down 
through a sieve from the top of a lead-tower. The chief 
repositories of the ores of arsenic are the following : 

BRITISH ISLANDS. The production of refined arsenic in 
the counties of Cornwall and Devon has been on an extensive 
scale tor nearly a century. In the year 1880 the production 
was 5,738 tons, of the value of 43,4987., and in 1881 the 
yield was 6,156 tons, of the value of 45,0707., being an aver- 
age value of about y/. 5^. 6d. per ton. The finer kinds realise 
io/. ios. per ton. This last quantity was produced by four- 
teen mines, worked otherwise chiefly for copper. Of these 
twelve were in Cornwall and two in Devon. In Cornwall, the 
largest quantity was produced at the Greenhill works, 1,628 
tons, and in Devonshire, the Devon Great Consols Copper 
mine produced 2,851 tons. The general composition of the 
ore whence this arsenic is derived is, arsenic 42-88, iron 
30*04, and sulphur 21*08 ; but these quantities are varied by 
proportions of copper, and sometimes tin. In obtaining the 
arsenic from the ore, the latter is first calcined in revolving cal- 
ciners, usually of a large size, 30 feet long and 5 feet diameter. 
These consist of iron tubes lined with firebrick. They are 
inclined about 7 in. to i ft. 6 in. from the horizontal, and 
are kept revolving where practicable, with water-power. The 
ore is put in at the upper end, and gradually passes downwards, 
parting with its arsenic by the way. These calciners are said 
to require but little fuel, the heat being largely kept up by the 
combustion of the arsenic itself. The crude arsenic is collected 
in long flues. Sometimes it is sold as so collected, containing 



256 EARTHY AND OTHER MINERALS. 

80 to 90 per cent, of arsenic. More frequently it is resublimated 
four times in reverberatory furnaces and collected as absolutely 
pure arsenous acid, white as snow, in flues and chambers. It is 
then ground in a mill to a fine powder, which finds its way 
down flexible pipes to a hole in the barrels waiting to receive it. 
These barrels are subjected while filling to a shaking motion, 
which causes the arsenic to settle down compactly, and the 
flexible pipes are so closely fitted to the holes in the barrels 
that no dust escapes, and in some works there is no smell 
whatever of arsenical fumes. Each barrel contains about 
3! cwt. Much the same process is practised at Joachimsthal, 
in Bohemia. The ores are roasted, the arsenic caught in lon^ 
flues and chimneys, and sublimated a second time, usually with 
a little potash. Probably there is less attention to some 
points of detail here, for it is said that the process is very de- 
structive to human life, few of the persons employed in the 
manufacture living beyond the age of thirty to thirty-five years. 

NORWAY AND SWEDEN. In Norway arsenical pyrites 
mixed with cobalt up to 35 per cent., occurs at Skuterud. An 
extensive bed of mispickel also occurs near Kongsberg, which 
contains a little gold. The mineral also occurs as arsenic 
silver in the great silver mine at Kongsberg. In Sweden I 
have seen vast beds of mispickel from 3 to 6 feet thick, extend- 
ing over the surface of the ground in the region between the 
towns of Ludvika and Fahlun. Similar deposits occur in the 
country between the towns of Norkoping and Nykoping, on 
the coast of the Baltic, and we shall see how largely the 
mineral is associated with the cobaltiferous ores of Gladham- 
mar, farther south on the same coast. 

In FRANCE native arsenic has been worked at the mine of 
St. Marie, probably now belonging to Germany. It occurred 
uniformly over a considerable distance between the hanging 
side of the vein consisting of slaty rock and the calcareous 
matrix of the lode itself. 

In GERMANY the sulphuret and oxide are found to some 
extent in the lead mines of the Hartz district, but all the 
ores are more abundant in the mines of silver and tin worked 



ARSENIC IN EUROPE AND AMERICA. 257 

on the Saxon side of the Erzgebirge, near Freyberg. Native 
arsenic exists in rounded masses composed of concentric layers, 
and containing up to 4 per cent, of silver. The sulphurets also 
occur in the vein stuff of the different lodes, and associated 
with the other ores worked. The same is true of arsenical 
pyrites. 

On the AUSTRIAN side of the mountains, at Joachimsthal, 
the oxide of arsenic occasionally appears in the form of quad- 
rangular prisms, and, more rarely, as a thin white efflorescence. 
As I have already intimated, the manufacture of arsenic from 
arsenical pyrites is carried on here. 

In TRANSYLVANIA realgar has been found as a vein a foot 
thick, traversing a dolomitic limestone. Near Nagyag it 
occurs in irregular masses, accompanying gold and silver ores. 
Near Felsobanya realgar occurs in the form of rectangular 
prisms. 

In all these mining districts orpiment also occurs, some- 
times in the form of small foliaceous masses. At Tayoba, in 
Hungary, it is found in small detached masses, as confusedly 
grouped together eight-sided crystals, and imbedded in a 
bluish clay. 

In RUSSIA native arsenic occurs in the Siberian mines in 
large masses. 

In SPAIN oxide of arsenic is found associated with cobalt 
in the valley of Gistain, in the Pyrenees. 

In ITALY realgar occurs as a volcanic production. It is 
found near Naples in the form of eight-sided crystals in the 
fissures of volcanic rock. It occurs also in the lava ejected 
from Vesuvius in the year 1794, and is found under similar 
conditions near Guadaloupe, in the West Indies, where it is 
known as red sulphur. 

Both realgar and orpiment are found in Kurdistan, in 
TURKEY in Asia, the latter being also obtained from CHINA. 

In the UNITED STATES OF AMERICA native arsenic occurs 
at Haver Hill, N.H., in mica slate, and also at Jackson in the 
same state. , 

The sulphurets are found in SOUTH AMERICA. 
s 



258 



CHAPTER XVI. 
COBALT. 

Cobalt, Origin of Name Description of its various Ores Commercial 
Varieties Cobalt in the British Islands Cornwall North Wales The 
Foel Hiraeddog Mine Norway, Skuterud Mine Indications about 
Kongsberg and Drammen Sweden Mining District, from Nykoping 
to Westervik The Cobalt Mines of Tunaberg, of Gladhammar Pro- 
cesses employed at the latter Mine for the Extraction of Cobalt from 
the Ores Mines of Hvena Germany, Riegelsdorf, Annaberg and 
Schneeberg Austria, Joachimsthal Past Production of Cobalt in 
Bohemia Spain Mine in the Pyrenees France America Imports 
into England Suggestions. 

THE name of this mineral is derived from Kobbold, which was 
the name given in Germany and throughout Scandinavia to the 
evil spirits of the underground regions in general, and the evil 
genius of miners in particular. It got this evil repute both 
from its deceptive appearance, once looking so much better than 
before its uses were discovered it was proved to be, and more 
than this, spoiling the copper ores with which it was associated. 
The ores of this mineral were of little or no use until the middle 
of the sixteenth century, when they were first employed to im- 
part a blue colour to glass, and subsequently for the colouring 
of porcelain and earthenware. For this purpose they are still 
very valuable. It is said that one grain of cobalt gives a full 
blue colour to two hundred and forty grains of glass. For 
these purposes the mineral is best adapted in a finely powdered 
state, the oxides of the metal being most suitable for use. 

In its metallic state, in which it is not found in nature, it is 
of a pale steel grey or tin colour, with a bright lustre. Its 
more compact ores also have a metallic appearance, with 



COBALT ORES. 

a specific gravity ranging from 6*2 to 7-2. The looser 
ores are of a reddish colour, and have a specific gravity of 
about 3. 

Until recently it has not been used in its metallic state, but 
probably it will become of great importance in this form, in con- 
sequence of the discovery within the last year or two by Dr. 
Fleitmann, of Iserlohn, Germany, of its value in the art of 
plating other metals, and for which in its metallic form it is now 
used, but in a limited extent, on account of its high price. In 
appearance cobalt plating is superior to that of nickel. The 
ores of cobalt are as follows : 

SMALTINE (Tin White Cobalt}. Chemical composition : 
cobalt 18 to 25 per cent., arsenic 69 to 79 percent. In colour 
tin white or steel grey. Its varieties are Cobaltine, containing 
33 to 37 of cobalt, with varying proportions of sulphur and 
arsenic. This variety has a silver white colour with a reddish 
tinge, 

RADIATED WHITE COBALT, or Chloanthite, containing 9 to 
14 per cent, of cobalt, and cobalt pyrites, or sulphuret of cobalt, 
or Linnaeite. 

EARTHY COBALT (Black Oxide of Cobalt, Asbolane). 
Chemical composition : usually oxide of cobalt 24, oxide of man- 
ganese 76, of a bluish black to black colour, in form both 
earthy and massive. 

COBALT BLOOM (Erythrine, Arseniatc of Cobalt}. Chemical 
composition : 37-6 of oxide of cobalt, with 38-4 of arsenic acid, 
and water 24*0. Of a peach and crimson red colour, varying 
to greenish grey ; possesses a foliated structure like mica. It is 
also called peach-blossom ore, and red cobalt ore. This is 
usually found in thin layers, or in small cavities and in aggre- 
gated crystals. Its varieties are Roselite, of a rose red colour ; 
Arsenite of Cobalt, a compound of oxide of cobalt and arsenous 
acid, resulting usually from the decomposition of other cobalt 
ores ; Sulphate of Cobalt, or cobalt vitriol, consisting of oxide of 
cobalt, sulphuric acid, and water. 

It will be seen that in nature this mineral is largely asso- 
ciated with arsenic, but its ores are distinguished from arsenical 



260 EARTHY AND OTHER MINERALS. 

pyrites by the blue colour they give with borax under the blow- 
pipe. 

The commercial varieties of cobalt are known as Zaffre, 
Smalt, and Azure. Zaffre is prepared by calcining the ores in 
a reverberatory furnace, by which the sulphur and arsenic are 
driven off, and the oxide of cobalt remaining is mixed with twice 
its weight of powdered silica. Smalt and azure, which have a 
rich blue colour, are made by fusing zaffre with potash and glass. 
Perhaps the best form in which the mineral is now sent into the 
market is that produced by the chemical process now in use at 
the Gladhammar mines in Sweden, as described farther on. I 
will now describe the principal deposits of cobalt ore in the 
world, including some that were formerly worked, for the sake 
of comparison as to their mineralogical conditions. 

THE BRITISH ISLANDS. Scotland. A considerable quantity 
of cobalt bloom was, towards the close of the last century, 
obtained from the copper lode worked for both copper and 
silver at Aloa, near Stirling, and traces of the mineral have 
been observed in the debris of the lead and copper mine of 
Newton Stuart, in Galloway. 

Cornwall?- In the year 1754 the Society for the Encour- 
agement of Arts and Useful Discoveries awarded a premium 
of 3o/. for the best cobalt found in England to Mr. Beauchamp, 
who mined some in Gwennap. The lode in which this was 
found also contained bismuth, which was thrown away until 
Dr. Albert Schlosser, who visited the mine in 1775, separated 
the cobalt from the bismuth and preserved both. The cobalt 
was discovered in a branch of a lode, while driving an adit upon 
Pengreep Estate, but it did not hold in depth. Cobalt had at 
that time been found at WhealTrugo, near St. Columb Major, 
in a vein 4 to 6 inches thick, where it crossed a copper lode, 
but the cobalt only continued a little way from the point of 
intersection. This ore was considered worth 6o/. a ton. Dis- 
coveries of small quantities were also made at Dudman's mine, 
in Illogan, at a mine near Ponsnooth, and in Dolcoath, which in 
a later period has produced good ore. Subsequently the mineral 

1 See De la Beche, Geological Report on Cornwall and Devon. 



COBALT MINE IN NORTH WALES. 



261 



has also been found near Botallack, at Polgooth, and St. Austell, 
as well as in a cross-course and adjoining a copper lode near 
Redruth. Unfortunately the mineral has not been discovered 
in sufficient quantities to yield much profit. 

North Wales. The only cobalt mine at present worked 
in Great Britain, is the Foel Hiraeddog mine, near Rhyl, Flint- 
shire. 1 The ore is found in one of the numerous cavities 
that occur in the lower massive limestones of the Carboniferous 
series, and which are locally known as " swallows." These 
" swallows " or " pockets " contain in this neighbourhood 
deposits of iron ore (haematite), and it was in working this 
pocket for that mineral that Mr. Gage, the proprietor, discovered 
the presence of both cobalt and manganese in the ore. He had 
noticed some black strings in the limestone, and on testing them 
with the blow-pipe, he found that the black colour was due to 
oxide of manganese in some cases and to oxide of cobalt in 
others. This led to a further examination of the ore of the 
pocket, which led to the discovery of the presence of cobalt ore 
of the nature shown in the following analysis : 



Samples. 





2. 


3- 


Cobalt sesquioxide . 
Nickel sesquioxide . 


37-40 
8-58 


20-63 
6-85 


26-20 

10-35 


Manganese binoxide 


23-12 


39-50 




Iron sesquioxide 


I3-85 


I5-IO 


21-10 


Copper oxide . . 
Silica 


traces 


traces 

2"OO 


0-25 
O'6o 


Alumina 


O'lO 


o-co 


0-18 


Water 




IS'OO 


IEJ-OO 












99-50 


99-58 


99-26 



The nature of the deposit will be explained by a reference 
to fig. 61. i is the irregular cavity or crack widened out in the 
limestone, stretching downwards to a depth of 240 feet or more, 
and varying in width from a string to 8 or 10 feet. It has 

1 Le Neve Foster, B.A.,D.Sc., F.S.S., 'On the Occurrence of Cobalt 
Ore in Flintshire,' Cornwall Geological Society, 1880. 



262 



EARTHY AND OTHER MINERALS. 



horizontally a north-north-east and south-south-west direction, 
and an extent of about 30 yards. For the most part it is per- 
pendicular in depth, but varies occasionally to the east and to 
the west. 2, 2, is red clay, which contains lumps of haematite 
ore, and lumps and grains of wad, earthy manganese, and 
asbolane, or earthy cobalt ore. The lumps are sometimes as 

large as a walnut or hen's 
egg, and when broken show 
a reniform or botryoidal 
structure ; they are of a 
black colour, and are soft 
enough to mark paper, and 
give a shining streak upon 
porcelain. 3, 3, are loose 
fragments of limestone im- 
bedded in the clay, and 
4,4, are the limestone beds 
themselves. The whole of 
the clay is not cobaltiferous, 
the whole of the width of 
10 feet being sometimes 
without any cobalt. The 
presence of cobalt in the 
clay is detected by taking a 
piece of the latter and 
drawing a portion of it over 
a piece of porcelain with 
the flat side of the blade 
of a knife, when, if a series 
of black shining streaks 

are formed, it is concluded that cobalt is present. Even 
this is not a certain test, as the earthy ore of manganese 
will produce similar streaks, so that chemical tests have 
frequently to be resorted to. The deposit has been followed 
down by a series of small shafts, and the only preparation of 
the ore at the surface is the picking out of it the lumps of iron 
ore and fragments of limestone. 




FIG. 61. SECTION OF CAVITY IN CARBONI- 
FERors LIMESTONE, FLINTSHIRE, CONTAIN- 
ING COBALTIFEROUS IRON ORE. 



DERIVATION OF COBALT ORE OF NORTH WALES. 263 

In this state its percentage of cobalt is very small, only 
ranging from i-o to 1-08 per cent., and the nickel from 0-4 to 
i -j per cent. The production and value of the ores have been 
as follows in the years given : 

Year. Tons. Cwt. Value. 

s. d. 

1878 .... 98 18 . . . . 616 17 o 

1879 .... 116 ii .... 833 2 5 

1880 .... 49 3 .... 297 6 4 

1881 .... 63 14 .... 309 12 8 



328 6 2,056 18 5 

This gives the average value of the ore at 61. 5-r. per ton. 
It will be seen that the value was greatest in the first year. 
With regard to the origin of the ore, iron is largely present in 
the reddish beds of the limestone, and still more so in beds of 
red shale and clay that form a marked feature in the limestone 
ridges all along their course. There are also some extensive 
deposits of iron pyrites, one very marked one occurring at the 
end of the Tarlagoch lead mines, at the end nearest Foel 
Hiraeddog. In the chapter on manganese I notice how largely 
manganese is disseminated throughout these limestone beds. 
We have not, therefore, far to look for the origin of the ores of 
the pocket. The haematite and the manganese are probably 
derived from the limestone beds and red shales. The cobalt 
may either have been originally associated with the manganese, 
or it may have been derived, which seems more probable, from 
the pyrites deposits, especially as a lump of the latter, that has 
been found at a depth of 30 ft. in the mine, has shown upon 
analysis traces of cobalt and copper. 

The discovery of cobalt and nickel in this pocket leads to 
the inference that similar pockets, of which there are many, 
may be mineralogically similar, and hence deserve a careful 
examination. 

NORWAY. Crossing the North Sea we find that cobalt has 
been, more or less, worked for the last hundred and ten years 
in Norway. A discovery of the mineral was made on the estate 
of Skuterud, in the parish of Modum, about fourteen English 



264 EARTHY AND OTHER MINERALS. 

miles from Drammen, in the year 1772. The ore occurred in 
beds (fahlbands), interstratified in gneissic strata like other 
mineral deposits of this age. The chief ore was cobaltine, 
which often occurred in a crystalline form. There were also 
arsenical pyrites containing at times as much as 10 per cent, of 
cobalt. There were in the same beds various ores of copper 
and other minerals. These all occur in gneissic rock. On the 
discovery of the ore the estate was purchased by the king, and 
works were established upon it in the year 1783, under German 
management. From 1827 to 1840 the mines were carried on 
by a private firm with considerable success, until the introduc- 
tion of artificial ultramarine for a time paralysed the industry. 
An English firm purchased the works in 1849, when the stock 
of cobalt sold for 8s. 6d. per Ib. At the present time the 
mines and works belong to a Saxon company, and in the year 
1882 the production of calcined cobalt ore amounted to 
160,000 Ibs. 

Similar beds, with copper pyrites, iron pyrites, arsenical 
pyrites with cobalt ores, occur in the gneissic rocks around 
Kongsberg, of which perhaps the most important are those 
until recently worked, and the ores smelted near Hougsund, 
between the towns of Kongsberg and Drammen. 

SWEDEN. Passing eastward into Sweden, we find deposits 
of cobalt ores associated with the copper ores, which in beds and 
lodes abundantly occur in the highly mineralised district that 
extends for some miles inland on the shores of the Baltic, from 
Nykoping on the north to below the town of Westervik on the 
south. 

In the north of this district there are what for many years 
were the important mines of Tunaberg. These mines are 
situated about twelve English miles south of Nykoping, and 
about two miles from the sea on the bay of Vik, at the head of 
which is the town of Norkoping. The rocks are, as usual, 
gneiss, through which a vein or lode runs in an east and west 
direction. The lode is largely filled with limestone ; possibly 
it may be a limestone bed in the gneiss, in which copper pyrites 
is but sparsely sprinkled, as is also arsenical cobalt pyrites or 



TUNABERG COBALT MINES, SWEDEN. 265 

cobalt bloom, but not abundantly. Galena is also present in 
small quantities. In the gangue of the vein or bed there is 
also a beautiful variety of green-coloured felspar, varying from 
light to dark shades of that colour, and aggregated in clusters 
of crystals. Serpentine also occurs, but rarely. 

An analysis of the cobalt ore obtained gave the following 
result : 

Cobalt 36-66 

Arsenic 49-00 

Iron 5-66 

Sulphur 6-50 

Loss . 2-18 



loo-oo 



The lode contracts and widens, and the quantity of ore it 
contains is very variable. Owing to this fact, the mine has 
passed through many stages. In the latter half of the last 
century it was vigorously worked with water-wheel pumps and 
other requisite machinery. During the present century it has 
been intermittently worked with varying success. In sorting 
the ores the lumps and crystals of cobalt are picked out, care- 
fully ground to powder, and packed in bags for the market, 
chiefly England; and it will be remembered that this mine 
differs from the next to be described by the separate occurrence 
of the cobalt from the copper ores. It is possible, however, 
that with increased knowledge it will be found that cobalt is 
more or less present in the copper pyrites themselves. 

At the southern end of the district referred to, and about 
ten English miles south of the town of Westervik, are the 
Gladhammar copper and cobalt mines, from which at the 
present time large quantities of cobalt are derived. 

These mines, a fine model of whose workings is to be seen 
in the museum at Stockholm, were opened as far back as the 
fifteenth century. They were worked first for iron, and at a 
later period on several occasions for copper, but they were 
always abandoned on account of the cobalt and nickel mixed 
up with the ores, the uses of these metals being then un- 



266 EARTHY AND OTHER MINERALS. 

known ; they were the Kobbolds, the evil spirits of the mine. 
Interesting relics of these early workings are seen in the tun- 
nels and chambers which were driven and opened by means 
of fire, before powder came into use for mining purposes. I 
had a very pleasant visit to these mines in the summer of 
1880, and perhaps I cannot do better than transcribe the 
description of the mines given to me on that occasion by the 
chief engineer and chemist, Herr Alfred Hasselbom, of Gote- 
borg, through whose energy and chemical skill the mines had 
been brought into successful working for cobalt. 

' The mines are some distance from the Farhult Station, on 
the Westervik and Hultsfred Railway. The metalliferous beds 
and deposits have a very great extent, stretching from the Ryss 
mine in the north-west to the neighbourhood of Lund, in the 
south-east, the whole length along which the principal ores are 
found being about 8,000 feet. 

1 The rock constituting this field is a quartzy eurit, that is 
to say, a rock containing quartz as its essential part, and which 
kind of rock is much renowned in Scandinavia as carrying 
deposits of pyrites, copper, nickel, and iron. The mineral 
deposits have a strike or direction from the north-west to the 
south-east, and have an inclination of 10 degrees from the per- 
pendicular to the south-west, the rock itself having the same 
direction and inclination. 

' The rock constituting the matrix in which the different 
ores are embedded is chiefly chlorite, commonly intermixed with 
hornblende and with magnetic iron ores. Mica also often 
occurs as matrix, which is especially the case in the Odelmark 
mine. In some cases the minerals have the quartz rock itself 
for their matrix. 

* The deposits of ores occur as beds and layers of varying 
extent and width, and generally the different beds are con- 
nected with each other through smaller cross veins, so as to 
form a complete network of ores stretching throughout the 
entire field ; but some of these connecting veins are too thin to 
be of any commercial value. The presence of magnetic pyrites 
in all these veins accompanying the ores of cobalt and nickel 



GLADHAMMAR COBALT MINES, SWEDEN. 267 

is well displayed by the inclinations and variations of the com 
pass. 

* The principal minerals occurring in the Gladhammar 
mines are the following, viz. : 

' Cobaltine in a pure state, with 30 per cent, of cobalt bloom, 
erythrine, and arseniate of cobalt. The other ores found are 
copper pyrites, occurring in all the beds, and rarely metallic 
copper, iron pyrites always carrying cobalt ; magnetic iron 
pyrites, zinc blende very scarce ; galena is found chiefly in the 
Holtandare mine; haematic iron ore, which with magnetic 
iron ore is so constantly mixed with cobalt that it may be con- 
sidered the chief matrix of the cobalt ores. In the north-west 
part of the field in the Ryss mine antimonium ore is found 
accompanying the copper pyrites. In the southern part of the 
property molybdenum glanz is found on the debris heaps left 
by the ancient workers. 

'The principal mines worked, together with their peculiar 
mineral features, are as follows : 

' Bonde Mine, which is about 70 ft. deep. Cobalt and nickel 
pyrites are found here, having a thickness of 3*5 feet, and they 
are intermixed with some zinc ores and galena. The continua- 
tion of this mine to the north-west is the 

' Holtandare or Baggen Mine, about 120 feet deep, yielding 
cobaltine, cobalt pyrites, with copper and iron pyrites. All of 
these ores are very rich and abundant. There is also galena 
and iron ore as the usual matrix for cobalt. 

1 The SvenskMine. This mine has been actively worked for 
a long time, and it has yielded a steady supply of cobalt and 
nickel, with copper pyrites and iron pyrites containing nearly 
2 per cent, of cobalt. This is an extensive deposit that con- 
tinues undiminished. It also seems to get richer in depth. It 
is to this mine that an adit level some 600 feet long was driven 
in ancient times by means of fire, probably to work the copper 
deposits. Running parallel to this deposit, about 20 feet to the 
east, is a valuable deposit of rich cobalt and copper. This is 
worked as the 

' Odelmark Mine. Tin white cobalt with cobalt pyrites, 



268 .EARTHY AND OTHER MINERALS. 

giving an average of 1 5 per cent, of cobalt, are obtained from 
this bed, and the yield is very large. This mine is worked to a 
depth of 100 yards. North-west of the Svensk mine, and on the 
run of the same bed, is the 

' Knut Mine, which has been continuously worked for some 
time. It produces the same ores as those of the Svensk. 

* Ryss Mines. These are about 1,500 feet north-west of the 
Knut Mine. They are old mines, and they have recently been 
re-opened. They yield copper pyrites and iron pyrites with 
cobalt, besides antimonium ore, Boulangerite? 

Some of the ores from the various mines are beautiful 
examples both of single and combined ores. 

Since the mines have been worked for cobalt, large quan- 
tities of both cobalt and copper have been obtained by screen- 
ing the old waste heaps, and it is computed that there still 
remains in these heaps about 50,000 pounds of metallic cobalt 
to be extracted by the process lately adopted. 

Until within the last few years the ores were simply picked 
or screened, and sold in this state, and the mines were success- 
fully worked on this plan. Three years ago, however, machinery 
and appliances were erected, under the direction of Mr. Has- 
selbon, for treating the mixed ores chemically, and which is now 
in successful working. The process is generally as follows : 

The ore when brought out of the mine is picked, and is 
broken to about the size of apples by a Blake's stone crusher. 
It is then calcined by mixing it with slack, and slowly burning 
it at a low heat until the sulphur and arsenic are driven off, or 
partly so. Then it is ground very fine in a mortar-mill, after 
which it is placed in a row of furnaces with an addition of 
alkaline matter. It is placed, first, in the furnace furthest from 
the fire, and is gradually moved forward to the hottest place. 
After it is taken out of the furnaces and cooled it is lifted to 
the top of a building in which there are three tiers of round tanks 
about 9 feet in diameter and 8 feet deep. There are ten 
of these tanks in each story of the building, and the fine-burnt 
ore is first placed in those of the uppermost tier, in which, as 
in all these, is water kept hot by steam being driven into it. 



COBALT DEPOSITS IN GERMANY. 269 

The iron is precipitated in the uppermost series of tanks, the 
liquid, with the contained copper and cobalt, being run off into 
the middle series, in which, by means of the addition of scrap- 
iron, the copper is precipitated. The liquid with the contained 
cobalt is run into the lowest series of tanks, and from there it 
is pumped into square compressors with flexible sides, and 
with fine gauze partitions ; a pressure of 100 pounds to the 
square inch is put on, during which the cobalt is caught and 
pressed into flat cakes between the gauze divisions, through 
which the water flows off clear. The cobalt now appears as a 
fine compact yellow substance, the cakes of which are taken 
from the press separately. The cobalt is next burnt and 
becomes black oxide, when it is fit for the most important pur- 
poses of manufacture. The copper is taken out of its tanks or 
vats, and, separated from fragments of iron, becomes a precipi- 
tate with from 80 to 90 per cent, of metallic copper. The 
iron is calcined and forms Indian Red. The refuse is carried 
through a series of twelve wooden tanks 8 feet long, 4 feet 
wide, and 4 feet deep, the result being ochres of various 
degrees of purity. These are ground upon the spot, and are 
ready for the painter. About 130 persons were employed at 
the mines at the time of my visit. The ochres and paints have 
a large sale in Sweden, Denmark, and Norway. The cobalt 
goes for the most part to Saxony. 

There are also cobalt mines at Vena, or Hvena, near Orebro, 
in Nerika. These were started in 1809, and for some time 
their exact position was not known. In 1880 the production 
of cobalt ore from these mines was 70,000 Ibs. 

GERMANY. An interesting series of deposits of cobalt occur, 
and have been worked more or less for more than a century, at 
Riegelsdorf, in Hessia, Germany. A series of veins or faults cut 
through the limestone and other beds that overlie the copper slate 
bed, which is famed not only for its copper, but also for the impres- 
sions of fish which abound in it, and around which the copper 
ore is richest. As these cracks come down upon the copper 
slate bed, they are charged with cobalt, which dies out upwards. 

On the Saxon side of the Erzgebirge, near Annaberg and 



270 EARTHY AND OTHER MINERALS. 

Schneeberg, cobalt ores are obtained from mines worked for 
other minerals. 

AUSTRIA. Cobalt has been obtained in considerable quan- 
tities from the mines of Joachimsthal, on the Bohemian side of 
the range of mountains just named. Here it is met with com- 
bined with the silver ores, and also in separate masses. As in 
Sweden, the ores of cobalt were here thrown away as useless, 
but since their value has been discovered the debris heaps have 
been carefully picked over. About a hundred years ago the 
yearly production of cobalt in Bohemia was given at 1,000,000 
Ibs.; at the present time it is not likely to be so much. 

In SPAIN, a cobalt mine has been worked in the valley of 
Gistain, in the Pyrenees. A gneissic rock is interstratified with 
beds of silicious and micaceous schists. Over this there is a bed 
of red felspar, on which rests a bed of dark bituminous schist 
of a friable nature, and varying in thickness from 30 to 60 feet. 
This bed is traversed by veins of cobalt which run from east to 
west, and range in thickness from half an inch to five feet; near 
the surface the ore is earthy cobalt, and in depth, arseniate of 
cobalt. The sides of the veins are also penetrated with cobalt. 
The veins do not pass out of the schist into either the red fel- 
spar or the limestone. 

FRANCE. On the French side of the Pyrenees cobalt was 
discovered in a vein of quartz that traversed a mass of ferruginous 
shale. The mine yielded large quantities, and the manufacture 
of the ores was conducted in works erected upon the spot. 

The mineral has also been worked in the Vosges, where it 
occurs in veins, having for its matrix crystallised carbonate of 
lime. It has also been found associated with silver ores in the 
mines of Allemont, in Dauphine. 

AMERICA. The mineral occurs plentifully in the State of 
Missouri, where it has been mistaken for black oxide of copper. 
It is largely obtained from the mine La Motte, associated with 
manganese. The ores are exported to England and refined 
there. The ores of the mineral are also obtained from Carolina. 
An analysis of samples of these showed oxide of cobalt 24, 
oxide of manganese 76. 



COBALT ORES IMPORTED INTO BRITAIN. 271 

The mineral is also found in smaller quantities in various 
other places. 

Unfortunately no return has been obtained for some years 
past of the imports of cobalt and several other minerals into 
England, but I am indebted to the kindness of Mr. Robert 
Hunt for the following information. 

In the years given below the imports were as stated : 

1859. 1863. 1867. 1870. 

Tons. Tons. Tons. Tons. 

Cobalt . . . . 16 i 5 44 

Ditto, ore ... 486 446 427 10 

Ditto, oxide . . 2 16 28 31 

In the year 1879, among the ores unenumerated, were 
from 

Tons. 

Norway 973 

Germany 215 

These returns include cobalt and nickel; in all probability 
about 400 tons of cobalt. 

The selling price of black oxide of cobalt in this country is 
from IQS. 6d. to i2s. 6d. per lb.; so that, with the increasing 
uses there are for the metal, any further source from which it 
could be obtained would be a boon to manufacturers. 

I would suggest that in this country the clay pockets in 
the Carboniferous limestone be well examined. In Sweden the 
debris from the numerous copper mines that have been worked 
in the district I have described would probably, if tested, be 
found to contain considerable stores of the mineral. 



272 



CHAPTER XVII. 

MOL YBDENUM ANTIMONY. 

Molybdenum, description of its Ores Commercial Uses British Islands : 
Inverness-shire, Charnwood Forest, Calbeck Fell Norway : Arendal, 
Numedal Sweden Description of the Deposits of Ekholmen, on the 
Baltic Coast Germany Austria Hungary America Antimony, 
Early Knowledge and Uses of Story of the Origin of its Present 
Name Native Antimony Ores of Antimony Uses of the Mineral 
Antimony in the British Islands Cornwall Sweden : Sala Mine, 
Ofverrud Mine, Gladhammar Mines Germany : Hartz and Erzgebirge 
Austro - Hungary Borneo Algeria America New South 
Wales. 

MOLYBDENUM. 

IT can hardly be said that Molybdenum has as yet been com- 
pletely reduced to a metallic state. When most nearly ap- 
proaching to this condition it is of a steel grey colour, with a 
specific gravity of 6 to 6*5. It rapidly oxidises on exposure to 
the air, especially with heat. 

Molybdenum is not a widely disseminated mineral, and 
hitherto it has been obtained in very limited quantities as 
compared with other minerals. It occurs in nature in three 
forms first and chiefly, as a sulphuret ; more rarely, secondly, 
as an oxide ; and thirdly, and more rarely still, in association 
with lead. 

i. MOLYBDENITE (Sulphuret of Molybdenum]. Of a pure 
lead grey colour, with greenish grey streak. Specific gravity 
4-5 to 4*75; occurs in lumps and masses, and in six-sided 
prismatic crystals, also in thin foliated plates and laminae. 
Chemical composition: molybdenum 59-0, sulphur 41-0; in- 
fusible before the blow-pipe, but gives off sulphur fumes ; par- 



MOLYBDENUM IN BRITAIN AND NORWAY. 273 

tially soluble in nitric acid, leaving a small residuum. It has 
the appearance of plumbago, and has a soft, greasy feel. 

2. MOLYBDIC or MOLYBDENA OCHRE, of an orange yellow 
or sulphur colour ; contains molybdenum up to 8 per cent. 

3. MOLYBDATE OF LEAD ( Yellow Lead Ore). Chemical 
composition : protoxide of lead 59 to 63 ; molybdic acid 30 
to 35, with small proportions of silica, and occasionally oxide 
of iron ; colour, straw or honey yellow, with a waxy or resinous 
appearance. Occurs in masses, and also crystallises in four- 
sided tables, and also in eight-sided prisms. 

For the quantities of the mineral raised, the ores of molyb- 
denum have in different combinations a varied use. In the 
manufacture of pottery molybdenum blue or blue carmine is 
used to impart a blue colour of great brilliancy and durability. 
This preparation is obtained by mixing molybdate of sodium 
with a solution of chloride of tin, when a blue precipitate is 
obtained, which, when dried, forms the colour referred to, and 
is ready for use. With tin salt as leys, this molybdenum blue 
can be used on wool and silk. A solution of molybdic acid 
on sulphuric acid is also used for dyeing silk a brilliant blue. 
Molybdate of ammonia is used for various chemical purposes, 
and in Sweden molybdate of sodium is used in medicine for 
the treatment of dropsy. 

BRITISH ISLANDS. In some of the Cornish copper and tin 
mines this mineral is occasionally met with, but scarcely in 
commercially paying quantities. Many years ago it was 
worked in the older rocks of the western part of Inverness- 
shire. It occurred in chloritic schists. I have seen it covering 
the smooth joint faces of the syenitic or fine-grained granite 
rocks of the Mount Sorrel quarries of Charnwood Forest. It 
has also been raised at Calbeck Fell, in Cumberland. 

NORWAY. In this country it is found associated with copper 
ores in the neighbourhood of Arendal on the south coast, and 
in those of the long valley of Numedal, leading up from Kongs- 
berg to the north-west. In both these localities the rock is a 
hornblendic gneiss. In SWEDEN important deposits have re- 
cently been opened and worked in the rich mineral district 



274 EARTHY AND OTHER MINERALS. 

extending along the coast of the Baltic, elsewhere referred to. 
I am able to describe these deposits more minutely. 

They occur on the island of Ekholmen (Oak Island), a 
little island situated in the Archipelago of Westervik, on the 
south-eastern part of Sweden, and about twenty miles north of 
the city of Westervik. The area of the island is 1,500,000 
square feet. The strata of the island consist of hornblendic 
gneiss and micaceous rocks. Through these strata, from 
north-west to south-east, and dipping to about 70 degrees to 
the south-west, run seven distinct veins. These veins or lodes 
vary in width from 6 inches to 2 feet. At one point four of 
these veins coalesce and form one deposit 5 feet wide. The 
contents of these veins are molybdenite, molybdic ochre, and 
copper pyrites, with a gangue of felspar and quartz. The 
lodes have a known length of 270 feet, and, where worked, 
they have been proved to a depth of 30 feet. Molybdenite, 
in a quite pure state, occurs in lumps weighing up to 5 Ibs. 
Where it occurs in smaller fragments and particles it is 
screened without difficulty to a state of great purity. In the 
summer of 1880, from the 2nd of June to the 2nd of October, 
three men raised from these lodes 1,400 Ibs. of pure molybde- 
nite, together with about 10,000 Ibs. of second molybdenum 
ore, having an average of 9 per cent, molybdenum, with 
about 5,000 Ibs. of unscreened ore. There is an absence in 
the contents of these lodes of phosphorus, wolfram, and other 
minerals which it is difficult to get rid of. The ore raised was 
sent to Germany, which is the chief market for nearly all the 
most valuable ores of Norway and Sweden. The prime ore 
realised 16^. per kilogramme (very nearly 2 Ibs.), or about 
25 per cwt. 

In GERMANY the mineral is found to a limited extent in the 
mines on the Saxon side of the Erzgebirge, imbedded in 
quartz and in a hard greenish marl. 

On the AUSTRIAN side of the same mountain range it is 
found at Zinnwald and Schlackenwald, in Bohemia. It occurs 
in quartz, which at the first place named is greasy and opaque, 
and at the latter place it occurs in plates in transparent quartz. 



ANTIMONY. 275 

In some of the mines of HUNGARY it is found in small 
rounded masses, like those of Ekholmen, which are deposited 
in a greyish coloured clay very likely decomposed from the 
surrounding rock. These masses are composed of large 
shining plates, closely adhering to each other. They contain 
a proportion of silver ranging up to 12 per cent, of the mass. 
In other mines in Upper Hungary molybdenum is found asso- 
ciated with gold. 

In the UNITED STATES of America it occurs at Haddam 
and Saybrook, in Connecticut ; at Blue Hall Bay, in Maine ; at 
Shutesbury and Burnfield, in Massachusetts; near the Franklin 
Furnace, New Jersey ; and near Warwick, New York. 

ANTIMONY. 

ANTIMONY is a mineral which has been known from remote 
times. It was the Stibium of some of the ancients, and was 
much valued as a dye for personal use. The sulphuret of 
antimony was also known as Alcofal, an Arabic word for a 
very fine powder, in which condition it was used for the adorn- 
ment of the face. The words alcophal, alcosol, and alqufocor, 
the name given to the fine powder of the sulphate of lead used 
by the potters, as well as alcohol, are probably derived from 
the same source. The more modern name, antimony, is said 
to have arisen from the experiments of Basil Valentine, a 
German monk. Basil having tried the effect of the mineral 
upon the pigs, found that after a preliminaiy violent purging 
they grew fat upon it. He therefore assumed that his brother 
monks would thrive upon a similar treatment. The dose he 
gave them unfortunately produced a very different effect, and 
they all died. The medicine then received the name of anti- 
monk, whence it passed to antimony. The mineral occurs in 
nature in the following forms : 

NATIVE ANTIMONY. In its metallic state, in which, how- 
ever, it occurs but rarely, antimony is of a brilliant tin or 
silvery-white colour, with a slight tinge of blue. It is usually 
associated with a little silver or iron ; it is crystalline in struc- 
ture, and is very brittle, and possesses a highly lamellated 



276 EARTHY AND OTHER MINERALS. 

structure. It fuses readily before the blow-pipe, and at a 
temperature a little above that of zinc. If the heat is increased 
it boils and passes off in fumes. Its specific gravity is from 
6*6 to 6*75. The native metal soon loses its lustre on ex- 
posure. It may be produced from its sulphuret by mixing 
4 parts of the latter with 3 parts of crude tartar and i^ 
parts of nitre, and placing the mixture in small quantities 
in a red hot crucible. Antimony is closely associated with 
several other metals cobalt, arsenic, copper, iron, zinc, silver, 
and lead. The presence of the metal is generally supposed 
to deteriorate the metals it is associated with. Thus, in the 
language of the miners, it " robs " the lead with which it is 
found. The native metal was first discovered in the silver lead 
mines of Sala, Westmannland, Sweden. 

SULPHURET OF ANTIMONY, STIBINE, ANTIMONITE, GREY 
ANTIMONY. Colour, lead grey with a grey streak and a 
blackish shining tarnish. Chemical composition : antimony 
71 to 73, sulphur 27 to 29. Occurs in various forms, massive 
and granular; also in thin laminae, and crystallised into 
fibrous and radiating groups ; brittle in texture, but, in a thin 
laminated form, slightly flexible; fuses in the flame of a 
candle, and vaporises rapidly before the blow-pipe. This is 
the chief ore from which the metal with its preparations is 
derived, and it comprises the following varieties. As we 
may not have occasion to refer to some of them again the 
localities where they are found are given. 

1. Arsenical Antimony. Colour, tin white with a reddish 
streak. Chemical composition : antimony 36*4, arsenic 33*6 ; 
occurs massive and granular. From Allemont and Bohemia. 

2. Berthierite, Hardingerite. Contains 9*8 to 16 iron, 52 to 
62 antimony, and 29 to 31 sulphur ; colour, dark steel grey with 
a yellowish or reddish tinge. From Auvergne and Anglas in 
France, Braunsdorf in Saxony, Tintagel and Padstow in 
Cornwall. 

3. Boulangerite. Colour, dark lead grey, inclining to blue, 
with a dark streak of a silky metallic lustre, finely granular, 
and in fibrous, radiating and columnar masses. Chemical com- 



ORES OF ANTIMONY. 277 

position : 24 to 26 antimony, 18 to 19 sulphur, and 56 to 58 
lead. From Moliere, in France, Gladhammar mines, Sweden, 
Ober Lahr, Lapland. Also found in Siberia. 

4. Feather Ore, Plumosite. Colour, dark lead grey. Chemi- 
cal composition: antimony 31, lead 50, sulphur 19. From the 
eastern part of the Hartz. 

5. Geokronite, Kilbrickenite. Colour, pale lead grey with a 
slight tarnish. Chemical composition : lead 67, with r to 2' of 
copper and iron, antimony 16, arsenic 4-7, and sulphur 17. 
From the Sala mines, Sweden, Me'redo, in Spain, and near 
Pietrosanto, Italy. Kilbrickenite, from county Clare, Ireland. 

6. Jamesonite. Colour, steel grey to dark grey ; occurs in 
parallel or radiating prismatic crystals. Chemical composition : 
antimony 36, lead 44, sulphur 20. From Cornwall, Estrama- 
dura, in Spain, Hungary, Siberia, and Brazil. 

7 . Kobellite. Colour, blackish lead grey to steel grey, with 
a blackish streak ; structure, columnar and radiate. Chemical 
composition : sulphuret of bismuth 33, sulphuret of lead 46, 
and sulphuret of antimony 13. Hvena, in Nerik, Sweden. 

8. Plagionite. Colour, dark lead grey; occurs in oblique 
rhombic crystals, also in thick tabular forms. Chemical com- 
position : antimony 37 to 38, lead 42 to 43, and sulphur 21. 
From Wolfsberg, in the Hartz. 

9. Steinmannite. Colour, lead grey ; occurs in cubes with 
cubic cleavage, and massive. Chemical composition : varying 
proportions of lead, sulphur, and antimony, with a little silver. 

10. Zinkenite. Colour, steel grey with a bluish tarnish, in 
six-sided needle-like prisms ; also fibrous and massive. Chemi- 
cal composition: antimony 44, lead 35, sulphur 21. From 
Wolfsberg, in the Hartz. 

The whole of these ores are soft, are easily scratched with 
the finger-nail. They have a specific gravity of 5*4 to 6*6. 

WHITE ANTIMONY, VALENTINITE. Colour, yellowish grey, 
greyish white ; also brown, grey, and peach blossom red, with a 
white streak with a pearly or adamantine lustre. Chemical 
composition: 83*6 antimony, and 16*4 oxygen; occurs in rect- 
angular crystals and in long tabular masses. Becomes yellow 



278 EARTHY AND OTHER MINERALS. 

in the flame of a candle, and fuses to a white mass ; soft, like 
the preceding ores ; gravity, 5-57. It has varieties 

1. Antimonate of Lead. A rare mineral of a yellow colour, 
ranging from grey and green to black. Chemical composition : 
oxide of lead 6r8, antirnonic acid 31-7, water 6*5. Occurs 
near Nertschinsk, in Russia. 

2. Red Antimony. Composed of both sulphuret and oxide 
of antimony. From the Hartz, Saxony, and Hungary. 

3. Romeine. Antimonate of lime, of a honey yellow colour, 
and hard enough to scratch glass. Occurs in groups of minute 
eight-sided crystals. Found in Piedmont. 

4. Senarmontiie. Colour, white to grey, more or less trans- 
parent, brilliant, resinous lustre. Composition similar to that 
of white antimony, but differs slightly in crystallisation. From 
Algeria. 

Antimony has been used from very early times for pur- 
poses of supposed personal adornment, being more particularly 
used by eastern ladies for darkening the eyebrows. It is also 
said to have been one of the first minerals used in medicinal 
preparations. Its use was proscribed in France in the year 
1566 on the ground that it was poisonous, and in 1609 a 
physician was expelled the faculty for having administered it. 
The prohibition was withdrawn in 1650, the mineral having 
then recently been received into the number of purgatives. In 
1668 a provision was made by which the use of it was limited 
to doctors of the faculty. It is now generally admitted that 
although some of its preparations are virulent as emetics, it 
may, with intelligence and care, be used safely with advantage. 
The tartar emetic of the apothecary is a mixture of antimony 
and potassa. As a paint for the bottoms of ships its oxide 
is very valuable, the use of it for this purpose being limited 
by its price. Among the more modern uses to which the 
inineral is applied is that of forming alloys with other metals. 
It hardens and improves the quality of tin, and is used in the 
manufacture of Britannia metal and pewter wares generally, 
Britannia metal being usually composed of 100 parts of block- 
tin, 8 parts of antimony, and 2\ parts of copper, or 2 parts 



ANTIMONY MINING IN BRITAIN. 279 

of copper and bismuth. An alloy of 17 to 20 percent, of 
antimony with lead makes the most approved type-metal, the 
larger the type the smaller the proportion of antimony. Small 
proportions of bismuth and copper are sometimes added. It 
is used with great success in the composition of alloys adapted 
to withstand great friction, as machinery blocks and bearings, 
and also for those used in the manufacture of scientific instru- 
ments, as well as in the manufacture of sheathing metal for 
ships, and of shot, shell, bullets, and balls. 

In the British Islands antimony has been profitably obtained 
from the mines of North Cornwall, and more particularly from 
the neighbourhood of Endellyon. Borlase refers to it as being 
obtained in that parish in 1758, and also those of St. Stephen 
and St. Austell. In the three years from 177410 1776 inclusive, 
according to Price, 120 tons of antimony were raised in Corn- 
wall, of which 95 tons were raised at Wheal Boys Mine in 
Endellyon, the price being from i3/. to i4/. 14^. per ton. The 
remainder was obtained from a mine near Saltash or Tred- 
innick, which has also subsequently been worked for the 
mineral. From 1800 to 1840 workings were carried on at 
intervals near Endellyon, at Trevatham, near St. Teath and 
St. Merryn. 1 The metal was discovered in Pillaton about the 
year 1819, 20 tons being raised in that year, 33 tons in 1820, 
and 79 in 1881. The principal ore was Jamesonite. In the 
year 1778 there were antimony works at Restronget Creek, 
Falmouth Estuary, the ore being the ordinary sulphuret. About 
the year 1856 Mr. James Bennet made a valuable discovery of 
the ore on Lady Molesworth's land, in St. Keev's parish. A 
recent discovery of the mineral near Liskeard shows, according 
to an analysis by Mr. M. W. Bawden, 60 to 70 per cent, of 
antimony, with 6 to 13 ounces of silver, to the ton of ore. The 
mineral occurs in the ordinary clay slate of the country in which 
the lead mines are worked, and it occurs in true lodes in the 
usual way. There have not been any returns of the mineral as 
raised during the last two years. 

SWEDEN. Both native antimony and sulphuret occur, the 
1 Geological Report on Cornwall and Devon. By Sir H. De la Beche. 



280 EARTHY AND OTHER MINERALS. 

former but rarely, in the Sala Mine, in the north-west of Sweden, 
Westmannland. They occur in association with lead ores, very 
rich in silver, that are found in lodes which traverse a primitive 
limestone from east to west. The mineral is also mixed with 
the grey copper ore of the Ofverrud Mine, in the parish of 
Glafva, Wermland. The occurrence of the mineral as in the 
form of boulangerite, along with cobaltiferous copper ores and 
ores of lead at the Gladharnmar Mines, near Westervik, is 
referred to in the chapter upon cobalt. Some of the specimens 
of the associated ores are very beautiful. 

GERMANY. Antimony ores occur in the two great mining 
districts of this empire, the Hartz and the Erzgebirge, in nearly 
all the varieties described. It is associated with the lead ore 
of the former district, and with the more mixed ores of the 
latter. It is also produced to some extent as sulphuret near 
Schemnitz, Kremnitz, and Felsbany, in the Austro- Hungarian 
Empire. Some years since the production of antimony in Ger- 
many reached 73,500 Ibs., and in Austro-Hungary 539,000 Ibs. 

BORNEO. This island has for some years past been the 
chief source of the supply of the mineral. Little is as yet known 
of the mineralogical conditions in which it occurs, except that 
it consists chiefly of antimony ochre, of which large quantities 
are shipped to England, to Hamburg in Germany, and Boston 
in the United States of America, where it is refined ; also to 
China. The chief mining districts are in Sarawak. Native 
antimony in a very pure state is also obtained. The exports 
of the mineral in the year 1881 from this State amounted in 
value to $72,516. 

ALGERIA. In this country, at Ani-bebbouch, in Gonstantine, 
sulphuret of antimony, as senarmontite, is largely worked, and 
is shipped in considerable quantities to England. It is found 
as octohedral crystals and in fibrous masses, and as botryoidal 
incrustations of a snow-white colour. 

In AMERICA antimony has been found in small quantities in 
the United States at Carmel, Maine, Gornish and Lyme, New 
Hampshire, and at Soldier's Delight, in Maryland. In the 
province of New Brunswick mining operations have been con- 



ANTIMONY OF AMERICA AND AUSTRALIA. 281 

ducted at Prince William. The ores occur in a number of parallel 
contact veins or deposits, occurring between different strata. 
These run east and west, and they have a number of small 
feeders running north and south. The ore is sulphuret, with 
native antimony rarely occurring. 

In NEW SOUTH WALES there werein the year 1881,862 acres 
of land let for the mining of the ores of antimony, the value 
of the ores obtained during the previous ten years being 1 1,8307. 

The lodes on the Munga Creek, near the Macleay River, 
traverse Devonian strata and contain the oxide and sulphide 
of antimony. The gangue of the lodes consists chiefly of 
quartz, and in this the ores of antimony occur in irregular 
bunches. Associated with the ores at Armidals there is free 
gold which is visible to the naked eye. The yield of antimony 
from various parts of Australia has largely increased during 
the last few years, and the mining of the mineral is becoming 
an important feature in the industry of the country. 



282 



CHAPTER XVIII. 

MANGANESE. 

Manganese in its Native State Rapid Oxidisation of Uses of the Ores 
of Manganese Alloys of the Metal with Iron and Copper Description 
of its Ores Manganese Ores of Great Britain and Ireland Cambrian 
Rocks of North Wales, of Scotland Silurian Strata of Ireland, of 
North Wales Silurian and Devonian Strata of Cornwall and Devon 
History of Manganese Mining in those Counties Devonian Strata of 
North Wales Carboniferous Limestone of Derbyshire, of Shropshire 
The Manganese Deposits of Nassau, North Germany Italy : Mines of 
Val d'Aosta and Tournanche Spain, Mines of the Huelva District, of 
Cape de Gata France : the Romaneche Mines, Cevennes, Vosges 
Occurrence of Manganese in the Mines d'Asprieres America 
Manganese Ores of Missouri Arizona Canada Inferences. 

IN its metallic state manganese is a greyish white metal of 
considerable brilliancy and of a granular texture, with much 
the same appearance as hard cast-iron, and of a very brittle 
texture. It is, however, an operation of much difficulty to 
extract the metal from its ores. Hydrogen and charcoal at a 
red heat reduce the superior oxides of this metal to the state 
of protoxide without eliminating the pure metal at that tem- 
perature, but at a white heat charcoal deprives the metal of the 
whole of its oxygen. 

Manganese oxidises very rapidly on exposure to the atmo- 
sphere, falling down in a black powder, and, as will be seen, it 
is in various stages of oxidisation that the mineral is chiefly 
found in its ores. The black oxide of manganese was for 
a long time known as magnesia nigra, from a fancied re- 
semblance to magnesia alba. Its true nature was first made 
out by Scheele in 1774, and almost immediately after- 



ALLOYS OF MANGANESE WITH OTHER METALS. 283 

wards Gahn obtained from it the metal now known as 
manganese. 

The ores of manganese are used in the arts for the genera- 
tion of oxygen and the manufacture of bleaching powder. The 
sulphide and chloride of manganese are used for colouring 
purposes in the printing of calico, the sulphate imparting a 
chocolate or bronze colour. Its ores are also used in glass 
manufacture, chiefly for giving a violet colour. Latterly the 
application of these ores has been considerably increased and 
extended by their use in the manufacture of various valuable 
alloys in conjunction with other more purely metallic minerals. 
Iron, for example, readily unites with manganese at a high 
temperature, and a proportion of the latter mineral makes the 
iron whiter and harder. It is also found that iron ore con- 
taining a small proportion of manganese is the best for the 
manufacture of steel. Nor is the tenacity of the iron destroyed 
by the admixture of a small portion of manganese, as much 
as 1*85 of the metal having been found in a bar of iron of good 
quality; and traces of the metal are found in good iron and 
steel from Russia, Sweden, and France. At the smelting- 
works at Dillenburg, in Hesse-Nassau, several valuable alloys of 
the metal are made with iron, copper, and tin. Mansfield 
refined copper, for example, mixed with u per cent, of man- 
ganese, forms the pure manganese bronze, which is capable of 
bearing a heavy breaking strain. A mixture of copper 85, 
tin 6, zinc 3, and cupro-manganese 3 parts, gives a casting that 
will bend to a right angle before showing fine cracks. An alloy 
also of great hardness, but workable with tools, is also made at 
the same works with 80 parts of copper, 10 parts of tin, and 
10 parts of manganese. Varying proportions of the mineral 
are used with iron, tin, copper, and zinc to produce results 
adapted to particular uses. The presence of a little iron in 
manganese imparts to it magnetic properties, and renders it 
less liable to rapid oxidisation, but the presence of manganese 
in any force destroys the magnetic properties of iron. 

The ores of manganese are the following, their specific 
gravity ranging from 3*4 to 5*2. 



284 EARTHY AND OTHER MINERALS. 

PYROLUSITE, from the Greek pur fire, and luo to wash, in 
reference to its use in taking away the green and brown tints 
of glass. Colour, iron black with a black streak. Chemical 
composition : 63-6 manganese, and 36-4 oxygen. This is the 
most abundant ore of manganese. It includes the varieties 
Varvardte and Polianite, which are of the same chemical com- 
position, but differing the first by containing a little water, 
and the second by its less hardness. Crystallises in small 
rectangular prisms. Specific gravity 4-8 to 5-0. 

PSILOMELANE, Greek psilos, smooth or naked, and melas 
black. Colour, greenish black, bluish black, and black, shin- 
ing reddish or brownish black streak. Chemical composition 
rather varied, 4*7 to n protoxide of manganese, 50 to 80 
hyperoxide of manganese, 6 to 1 6 baryta, 2 to 5 potash, o to i 
copper, and 0*5 protoxide of cobalt. Associated in the same 
mines with pyrolusite, the two often occurring in alternate 
layers. It is an abundant ore. Its varieties are Heteroclin and 
Marcelline, or Braunite, containing 10 to 16 per cent, of silica. 

MANGANITE. Chemical composition : 89-9 of peroxide of 
manganese and 10*1 water. Occurs in rhombic prisms, and 
also in a massive form. Specific gravity 4-3 to 4-4- Colour, 
dark steel grey to iron black, often brownish black, with a 
tarnished brown streak. 

MANGANESE SPAR (Rhodonite). Occurs in oblique rhombic 
prisms and also in large masses. Colour, dark rose red, bluish 
red, or reddish brown. Specific gravity 3*5 to 3 '6, translucent, 
vitreous, or pearly. Not affected by acids. Chemical com- 
position : 45*33 silica, and 53*67 manganese protoxide, with 
3 to 5 lime, and o to 6 iron protoxide. Its varieties are 
Bustanite, from Mexico, of a pale greenish or reddish grey 
colour, with 14 lime; Fowlerite, from New Jersey, with 7 to 
n iron protoxide ; Tephroite, also from New Jersey, with 29-8 
of silica, and 70*2 of protoxide of manganese. Less definable 
varieties are, Paisbergite from Sweden, and Hydropite, Photidte, 
Allagite, and Horn Manganese. 

CUPREOUS MANGANESE. Colour, black, inclining to blue 
and black. Specific gravity 3-1 to 3-2. Opaque, rather brittle 



ORES OF MANGANESE. 285 

or friable. Chemical composition : 14' to 17* copper protoxide, 
1*6 baryta, 2*5 lime, 0*2 to o'6 protoxide of cobalt and nickel, 
15 to 17 of water, with frequent admixtures of other sub- 
stances. 

CREDNERITE. Chemical composition: 42*85 copper pro- 
toxide, and 57*15 peroxide of manganese. Colour, iron black 
with a brownish black streak. 

TRIPLITE {Ferruginous Phosphate of Manganese). Occurs 
in a massive form. Colour, blackish brown. Chemical com- 
position : protoxide of manganese 33*2, protoxide of iron 33*6, 
phosphoric acid 33*2, with a little lime. Its varities are Hete- 
rosite, with 41*77 per cent, of phosphoric acid, and Huraulite, 
with 38 of phosphoric acid, and 18 per cent, of water. 

WAD (Bog Manganese). Earthy or compact ; also occurs 
in coatings and dendritic forms. Colour and streak brown or 
black. Chemical composition very varied, but consists usually 
of from 30 to 70 per cent, of peroxide of manganese, mixed 
with varying proportions of peroxide of iron, and the oxides 
of copper and cobalt, and with from 20 to 25 per cent, of 
water. Like bog iron ore it is formed in marshy places from 
the decomposition of substances containing manganese. 

Besides the above there are Hausmannite, a sesquioxide of 
manganese, containing when in a pure state 72 per cent, of 
manganese, found in Thuringia and Alsatia. Peloconite from 
Chili, a mixture of manganese and iron. Manganblende or 
Alabandine; chemical composition : 31 protoxide, and 69 perox- 
ide of manganese, or 72-4 manganese, and 27-6 oxygen, the 
proportions varied by proportions of sulphur, occurs with 
gold in Transylvania. Hauerite from Kalinka, near Neusohl, 
in Hungary ; colour, reddish brown to black ; chemical com- 
position : 46-28 manganese, and 53*72 sulphur. Diallogite or 
red manganese; chemical composition : 62 protoxide of man- 
ganese, and 38 carbonic acid, varied by the carbonate of lime 
o to 13, magnesia o to 7, or iron o to 15 ; the Hartz, Saxony, 
and Hungary. Its variety, Wiserite, is silky and fibrous and 
contains water. There is also the arseniuret of manganese, 
greyish white in colour with a black tarnish ; chemical com- 



286 EARTHY AND OTHER MINERALS. 

position: 4275 manganese, and 57*25 arsenic, with a little 
iron, found in Saxony. 

GREAT BRITAIN AND IRELAND. In the British Islands 
we find these ores in a widely disseminated form, and also 
in masses sufficiently concentrated for successful mining. In 
the former state it permeates the Cambrian slates of North 
Wales, or rather the metamorphic rocks by which they are 
traversed, forming the beautiful moss and tree-like forms sold 
to visitors to the principal slate quarries as 'landscape stones.' 
It is gathered into small nests, bunches, and strings in the 
porphyritic and ash beds of the Llandeilo strata of the Princi- 
pality. The lower dolomitic beds of the Carboniferous rocks 
of England and Wales are also covered and permeated with 
the same dendritic or tree-like forms, and the ores are gathered 
into cracks and cavities. There are also curious pockets of 
loose sand with a manganese nucleus and radiations in the 
thick sandstone beds of the millstone grit, and a reference to 
the chapters in this work descriptive of the phosphate of lime 
deposits of the world will show how persistently and universally 
this mineral has been associated with the ordinary qualities of 
phosphate of lime through all time. Let us now notice it 
as it is gathered into deposits sufficiently large to induce 
attempts at mining, beginning with the oldest strata in which 
such attempts have been made. 

Cambrian Rocks. About thirty- five years ago there was 
considerable activity in Carnarvonshire in seeking for man- 
ganese ores in the strata associated with the slate rocks of that 
county, without, however, leaving any permanently practical 
results. The deposits occurred in strings and small nests here 
and there, but not extensive enough for working. 

In Scotland, in rocks of a similar or, it may be, older age 
than Aberdeenshire, a vein of manganese of considerable 
extent was discovered and worked for some time in the latter 
part of the last century. The ore was, however, extremely 
hard, being largely mixed with quartz and baryta, and it was 
further intimately combined with silica, and altogether it was 
extremely difficult to reduce it to powder. It is on record 



MANGANESE DEPOSITS OF WALES AND CORNWALL. 287 

that this mine yielded some beautiful specimens of the radiated 
gray ore. 

Silurian Strata of the South of Ireland. The Glandore Mine, 
near Cork, has been worked for some years in slaty rocks. 
The ore lies in what appears to be the junction of two lodes. 
It is mixed with spar and some iron ore. The production of 
this mine in 1881 was 250 tons, of the value of 43 5/. 

Lower or Cambro- Silurian Rocks of North Wales. Mining 
operations have been carried on at irregular intervals in the 
slaty rocks of the region between Festiniog, Trawsfynydd, 
Bala, and Dolgelly, with their interstratified ash, felspathic and 
porphyritic rocks. In the slaty rocks the ores of manganese 
occur in irregular veins or joints, which open and close at 
intervals along their course, and at the intersection of these 
with floors or horizontal joints in the rocks. Hitherto the cost 
of carnage in that district has been fatal to the successful 
mining of so low priced a mineral, and it is very doubtful if the 
ore exists in sufficient quantities and in masses concentrated 
enough for profitable mining. Probably now that the region 
is opened up by railways new attempts will be made. 

Silurian and Devonian Strata of Cornwall and Devon. 1 
Borlase refers to manganese as raised on Tregoss Moors 
in the year 1754, and mentions it was used for glass making 
and the manufacture of Egyptian ware in Staffordshire, for 
which purposes it seems to have been wholly employed until 
it came into use for bleaching. About the years 1760-70 
manganese ores were found at Upton Pyne, near Exeter. 
Other deposits were discovered about the same time at 
Newton St. Gyres, in the same neighbourhood. This group 
of mines for some years yielded from 200 to 300 tons a 
year, at prices ranging from 30^. to 3/. per ton, but they 
became exhausted, Upton Pyne about 1810, and Newton St. 
Gyres soon afterwards. But about the same time similar ores 
were discovered and worked at Doddescombleigh, Ashton, 
Criston, and other places. About the year 1815 manganese 
deposits were discovered and worked in the neighbourhood of 

1 De la Beche, Geological Report of Cornwall and Devon, p. 609. 



288 EARTHY AND OTHER MINERALS. 

Tavistock and Launceston. Subsequently the ore was raised 
in the vicinity of St. Stephens, and discoveries have continued 
to be made in the original localities and to the north-east and 
south-west of them until now. 

Between the years 1804 to 1810 the quantity of manganese 
shipped from Exeter amounted to 3,000 tons a year. In 1821 
the quantity raised in the two counties was estimated at about 
4,000 tons. In 1839 the production was taken at 5,000 tons, 
of the very high value of 8/. per ton. At the present 
time there are sixteen manganese mines in the two counties, 
five of which produced, in 1881, 1,855 tons of ore, of the 
declared value of 4,9227., or rather less than 2/. 14^. per ton. 
Of these mines, Chillaton and Hogston, Ruthen, Lydcock, and 
West End Down, Whetstone and Rose Exbridge, the first- 
named, produced 1,224 tons. The average price is, however, 
reduced by the inclusion of 140 tons of manganiferous iron ore 
at Rose Exbridge which only realised i^s. gd. per ton. The 
ore from Chillaton and Hogston realised 3/. IQS. per ton. 

Concerning the geological age of the manganese mines of 
Devon and Cornwall, it may be stated broadly that the mines 
extending from Launceston and Tavistock to the south-west 
occur in Silurian strata, and those to the north-east in beds of 
Devonian age. There is a considerable difference in the 
modes of the occurrence of the ores in these two groups of 
rocks. In the older or Silurian strata the ores occur chiefly as 
in rocks of the same age already described in North Wales, in 
veins, chiefly cross crosses from lodes of other minerals, ir- 
regular fissures, and at junctions of the same with lines of 
bedding. In the Devonian strata the ores occur chiefly in 
irregular masses that occupy portions of the strata themselves, 
and are probably of contemporaneous age. Where the ore is 
collected into previously worn cavities and fissures, there are 
often beautiful examples of crystallisations. 

Several of the ores of manganese are found throughout the 
two counties braunite near Launceston, psilomelane at 
Upton Pyne, and bisilicate of manganese near Tavistock and 
Callington but the prevailing ore is pyrolusite, or grey and 



MANGANESE IN DEVONIAN STRATA OF WALES. 289 

black ore, containing 70 to 79 of peroxide of manganese. This 
is combined with variable quantities of silicious and aluminous 
matter and oxide of iron. 

The ores are associated with those of iron, but as in most 
other mines, the two classes of ores are distinct, and occupy 
separate parts of the same deposit, the ores of the Rose 
Exbridge mine forming an exception. 

The Devonian Strata of North Wales. At the base of the 
Carboniferous limestone of Denbighshire, along its course from 
the Eglwyseg cliffs near Llangollen to near its termination on the 
mainland in the promontory of the Great Ormes Head, there 
are nearly continuous patches of Devonian strata, correspond- 
ing probably to the upper division of that group. These strata 
consist of dark red sandstone, conglomerates of pebbles de- 
rived from the older rocks, hard shales, and impure limestones. 
The whole series rests upon a waterworn floor of the Wenlock 
beds of the Upper Silurian strata. 

Deposits of haematite have at various times, including the 



y K. 




FIG. 62. SKETCH SECTION OF NANT UCHAF MANGANESE AND HEMATITE MINE, NEAR 
ABERGELE, NORTH WALES. 

i, Beds of Conglomerate, Red and Blue Marl, and impure Limestone, part of the 
Devonian Series. 2, Manganese and Haematite Deposit. 3, Wenlock Shale, 
Silurian. 4, Fault. 

present, been worked in these beds. Within the last few years 
a rather extensive deposit of manganese ore, associated with 
haematite, has been discovered at Nant Uchaf, near Abergele. 
From this deposit, in 1881, 305 tons of manganese ore were 
raised, of the average value of i/. per ton. 

u 



290 EARTHY AND OTHER MINERALS. 

Fig. 62 will give an idea of the nature of this deposit. It 
shows the haematite and manganese ores as occurring in ir- 
regular masses in the impure limestone beds. These masses 
owe their origin either to an original deposition contem- 
poraneous with the disposition of the -beds themselves, or by 
the subsequent infiltration of mineral matter into cavities made 
in the limestone. From their extent and position, as well as 
from the light thrown upon these more ancient deposits by the 
newer ones of Nassau and elsewhere, to be described, I incline, 
in the absence of evidence to the contrary, to the first supposi- 
tion. This deposit is interesting from its stratigraphical rela- 
tion and similarity in other respects to the Devonshire mines, 
showing, as it does, similar mineralogical conditions in strata 
of the same age in widely-separated areas. 

Carboniferous Limestone, Derbyshire. Manganese has been 
mined for a long time in the Carboniferous limestone of 
Derbyshire and in its immediately overlying clays of local 
derivation. It was formerly supposed to be an iron ore, 
but its true nature has been known for over a century. It 
occurs chiefly as wad, in earthy masses not unlike balls of 
soot, crumbling to pieces on exposure to the atmosphere, but 
it shows when broken a few traces of its metallic nature in the 
shape of numerous minute shining veins. The deposition of 
the manganese in bulk is of an age subsequent to that of the 
deposition of the limestone. It seems to have been washed 
out of the latter, through which it was originally distributed, 
occurring more abundantly near the lines of bedding, and to 
have been deposited in cracks, irregular fissures, and worn 
surfaces of the limestone beds. In the year 1881 eight Derby- 
shire mines yielded an aggregate of 474 tons of ore, of the 
value of yio/. 

Shropshire. A manganese mine was worked some years ago 
at Pant, near Oswestry, which is interesting as illustrating the 
Derbyshire deposits just referred to, and as throwing some 
light upon the Nassau deposits, to be described. A waterworn 
hollow in the rather impure limestone was filled with a com- 
pact white clay of pre-glacial age. At the time of my visit a 



PRODUCTION OF MANGANESE IN GREAT BRITAIN. 29 1 

short tunnel had been driven and a chamber opened in the clay. 
In excavating this chamber several nests and pockets of man- 




FIG. 63. SECTION OF A MANGANESE MINE AT PANT, NEAR OSWESTRY, SALOP. 

A, Stiff clay. B, Carboniferous Limestone. C C, Pockets of Manganese. 
D, Entrance of Level. 

ganese were found, and others remained in the sides of the 
chambers as shown in fig. 63. 

I have already observed that these limestone rocks in the 
neighbourhood abound with dendritic impregnations of man- 
ganese, and that the millstone grit beds are dotted with pockets 
containing loose sand and a manganese nucleus. The man- 
ganese of the Pant Mine, therefore, seems to be the washing 
out of the mineral from the rocks to which it originally be- 
longed, an operation that was continued through a long period 
of time. We also see how the manganese was accumulated 
into distinct masses in the clay, partly as the result of chemical 
affinity and partly of mechanical action. 

The total production of manganese in the British Islands in 
the year 1881 was 2,884 tons, of the value of 6,44i/. There 
was also imported from other countries during the same period 
18,743 tons, of the value of 71,1497., or nearly 4/. per ton. The 
discrepancy between the value of British and foreign ore may 
be partly accounted for because with the British we have given 
its value at the mine, and in the case of the foreign its value 
when brought to port. It is also unlikely that low-class ores 
would be shipped at all from foreign mines. 



292 EARTHY AND OTHER MINERALS. 

We will now proceed to notice the manganese deposits of 
other countries, whence these importations are derived. 

The various ores of this mineral are found in the older rocks 
of Sweden, of Russia, and of those of the chief mining districts 
of Austria and Germany, under conditions similar to those in 
which they are found in the British Islands. In Russia, a 
valuable deposit of manganite is worked at Tagel, in the Urals, 
and the mineral is used in the manufacture of steel. Figs. 64 
and 65 give a plan and section of the manganese mine worked 
in the older slaty strata at Elbingerode, in the Hartz mining 
district, Germany, which was long successfully worked. The 
figures will explain the nature of the deposit, and I will pass on 
to notice the more recent, comparatively speaking, deposits of 
the Lahn Valley, in Nassau, North Germany. 

GERMANY. 1 The deposits of manganese just referred to 
occur in the valley of the river Lahn, a river that enters the 
Rhine about three miles above Coblentz. They are generally 
co-extensive with the deposits of phosphate of lime described 
in this work. They stretch from the village of Baldwinstein, 
between the towns of Nassau and Diez, north-eastward by 
Limburg, and as far east as the town of Hadamar, by Dehren, 
Diet Kirchen, and round by Heckolshausen to the town of 
Weilburg, and on to Wetzlar and Giessen. The basement 
rocks of the whole district, as shown in the section, Fig. 36, 
are shales, slaty rocks, and sandstones belonging to the Lower 
and Middle Devonian strata. These are surmounted by a 
dolomitic limestone, No. 5 of figs. 67, 68, 69, 70, 71. This is 
surmounted in limited areas by shales ( Cypridinen Schiefer] of 
Upper Devonian age. Over the greater part of the whole area 
there is a deposit of compact clay of from 10 to 50 feet in 
thickness (No. 3 of figures). This in its turn is overlaid by a 
drift composed chiefly of quartz detritus (Quartz Geschiebe) 
No. 2, and Dammerde, or soil No. i. Immediately upon the 
limestone there sometimes rests a sand-bed (No. 6), which 
seems to consist of the sandy particles originally belonging to 

1 F. Odernheimer, Das Berg und Huttenwesen im Herzogthum. Nassau . 
The author also examined several of these deposits in the summer of 1867. 



MANGANESE OF ELBINGERODE. 



293 




2Q4 EARTHY AND OTHER MINERALS. 

the limestone, the calcareous matter having been dissolved and 
carried away. 

It is upon the worn edges of the limestone, as shown in 
figs. 67 to 71, that the deposits of manganese, accompanied 
by those of haematite as well as those of apatite, as described 
in the chapters relating to that mineral, occur. The limestone 
itself is frequently impregnated with manganese. It also con- 
tains little cavities in which are crystals of carbonate of lime, 
manganese spar, and pyrolusite of a dark blue or grey colour. 
The ores of manganese contained in the layers and nests in the 
clay above the limestone consist of pyrolusite, psilomelane, 
manganite, and wad. In the layers pyrolusite and psilome- 
lane are in separate nests ; wad and manganite occur promis- 
cuously. Ironstone of several varieties, but chiefly haematite, 
are found associated with the ores of manganese. As shown 
in the accompanying figures, they generally occur in distinct 
layers, but ores of iron are not unfrequently found adhering to 
those of manganese. Where there are two layers of manganese 
the lowest is usually more mixed with ironstone than the upper- 
most, besides which the ore of the top bed is better in quality. 

The figures 67 to 71 will illustrate the various modes of 
the occurrence of the ores. Fig. 66 is the plan of a haematite 
deposit near Niedertiefenbach, and figs. 67 and 68 show 
respectively a longitudinal and cross-section along the lines 
intersecting the plan. It will be seen that there are here large 
deposits of both manganese and haematite. It is also interest- 
ing to notice how distinct the two deposits are, and that where 
the haematite is at its greatest strength the manganese fails, 
and that the haematite fails where the manganese is present in 
full force. 

In fig. 71 we have a section of the Hochst Mine in the 
same locality. Here there is interposed between the lime- 
stone and the manganese deposits a considerable thickness of 
shale, known to the miners as schaalstein, but which must not 
be confounded with the schaalstein containing cyprina. There 
are here two manganese layers, and in the schaalstein there is 
a continuous layer of brown ironstone. 



MANGANESE OF STEETERWASEN. 



295 




FIG. 66. PLAN OF HAEMATITE DEPOSIT IN STEETERWASEN MINE, NEAR NEIDER- 
TIEFENBACH. 




FIG. 67. CROSS SECTION ALONG LINE A B OF THE SAME. 

4 




FIG. 68. LONG SECTION ALONG LINE C D OF THE SAME, SHOWING MANGANESE. 

i, Soil. 2, Quartz Drift. 3, Clay. 4, Shale. 5, Limestone. 6, Sand. 

7, Manganese, q, Haematite. 



296 EARTHY AND OTHER MINERALS. 

In fig. 69 a continuous layer of manganese rests upon an 
equally continuous layer of mulm or sand, both following the 
worn edges of the limestone. In fig. 71 we have an example 
of the thinning out of both mulm and manganese, with the 
occurrence of brown ironstone, and of the same containing 
nests of manganese occurring over the manganese. 

The thickness of the manganese varies from 6 inches to 
15 feet, the average thickness taken from a great number of 
mines being i foot 6 inches. 

The average quality of the manganese obtained from these 
different workings is about 63 per cent, of peroxide of man- 
ganese. The quantity obtained from one square lachter 
5 feet x 5 feet x 5 feet, is about 5 tons. Some years since 
there was computed to be in the district 2,800,000 quad- 
ralachters of the mineral ; the mines numbered 259, and the 
production had reached 25,000 tons a year. 

Farther north, where the rocks beneath the limestone come 
to the surface, there are numerous small accumulations of 
manganese in them, ancf the ore is widely disseminated 
through them. I have already noticed that manganese occurs 
in the limestone itself. In all probability, therefore, these 
masses of the mineral are due to the same wearing down and 
washing out processes already described, by means of which 
the manganese has been extracted from its parent rocks, and 
accumulated in layers and nests, as we now find. The stiff 
clay belongs to an age preceding the long and somewhat inde- 
finite period known as glacial. 

The mining is very simple. As in the mining for apatite 
in the same region, small shafts are sunk through to the clay. 
These are, where the clay is wet or loose, cased with wicker- 
work. Speaking from experience, I can say that the under- 
ground workings are tortuous and intricate, like a rabbit- 
warren. Little or no timber is used, the clay ordinarily 
being strong enough to stand without assistance for the time 
required. Mining operations are confined chiefly to the 
summer months, partly because of the drier state of the clay 
then, and also on account of the washing of the ore, which is 



MANGANESE DEPOSITS OF NASSAU. 



297 




FIG. 69. SECTION OF THE RUBIN MINE, NEAR NIEDERTIEFENBACH. 




FIG. 70. SECTION OF THE FAHRWEG MINE, NEAR NIEDERTIEFENBACH. 






.. 




FIG. 71. SECTION OF THE HOCHST MINE, NEAR NIEDERTIEFENBACH. 

i, Soil. 2, Quartz Drift. 3, Clay. 4, Shale. 5, Limestone. 6, Sand. 7, Manganese. 
8, Brown Ironstone with nests of Manganese. 



298 EARTHY AND OTHER MINERALS. 

done on tables and on troughs in the open air by youths and 
young women by the side of the nearest stream where prac- 
ticable, by the side of the river Lahn itself. 

Cheaply as the mining is conducted, it is difficult, after the 
freight down the Lahn to the Rhine, the transhipment to 
Rhine barges, the transhipment to seagoing vessels, and the 
freights down the Rhine and by sea to England are paid, to 
make mining manganese in this district for exportation to 
foreign parts to pay. 

ITALY. A group of manganese mines has been worked 
for more than a hundred years in the Val d'Aosta and the 
Val Toumanche, Italy. They seemed to have been worked 
for other minerals at a much earlier period, it is said by the 
Romans, who left a large quantity of ore about the mines. 
The names of this group of mines are, St. Marcel, now worked 
on a lode ; Tourgnon, also worked on a lode ; Val Tou- 
manche, worked on an immense irregular deposit ; and Bar- 
donecha, worked on a series of nearly horizontal beds, which 
are about one metre thick. The ores are the ordinary oxides, 
varied with proportions of sulphur. They frequently occur in 
a crystalline form, and all of them contain a small proportion 
of silver. 

It is probable that the lodes referred to are simply branch- 
ings out from the great irregular masses and beds in which the 
workings were first prosecuted. Thus Saussure describes the 
mine of St. Marcel, nearly a century ago, as * situated on a 
mountain of gneiss, the beds of which are in a horizontal posi- 
tion. The mine is entirely open to the day, and the ore is 
supposed to be deposited in a large mass rather than in a 
bed or a vein. It lies parallel to the strata of the mountain, 
and it is about 15 feet in thickness where it appears on the 
surface; but it gradually diminishes as it enters the moun- 
tain to the thickness of 5 or 6 feet. It has been penetrated 
about 50 feet, and it does not appear to exceed 200 to 300 
feet in length. Its inclination from the west is at an angle of 
15 to 20 degrees. The mine affords fine specimens of the 
red ore or carbonate of manganese, which are of a beautiful 



MANGANESE DEPOSITS OF WESTERN SPAIN. 299 

red colour, and crystallized in the form of rhomboidal 
prisms.' 

In a recent statement the costs of working the St. Marcel 
mine are thus given. Mining, per ton, 15 francs, royalty 5, 
carriage to highway 30, along highway to railway station 15 
= 65 francs. The value of the mineral is put at 4/., so that 
deducting 65 francs = 2/. 12^., a profit of i/. 8s. per ton is 
left. In this statement there is nothing put down for explora- 
tion and dead work, nor for management, so that it is probable 
that in actual experience the margin of profit would be reduced. 

SPAIN. In the mining district of Huelva, Spain, represented 
on the annexed map, fig. 72, a district famous for its rich 
pyrites and hsematite deposits, a very large quantity of man- 
ganese has been raised, there being some years since some 
150 miners at work. These manganese mines stretch over the 
south-west part of the province of Huelva, with a portion of the 
contiguous part of Portugal. The greater, part of this region 
lies about 800 feet above the sea. It is an unfruitful region, 
the population being chiefly supported by the mines. 

The manganese lies in clay slate belonging to the Silurian 
group of strata (Lower Silurian probably). The rock is of a 
greyish colour and shining appearance. The general strike of 
the strata is from north-east to south-west, with a dip of from 
40 to 50 to the south-east. Between the villages El Alosno 
and Castillejos these schists are about a mile long and 2,000 
feet in thickness, very compact, and with protrusions of felspathic 
and greenstone porphyry rocks. The manganese occurs in the 
clay slate in the vicinity of these harder rocks, and often at the 
point of contact between them and the clay slate. It is asso- 
ciated with quartzites and small ironstones, of both of which 
there are layers and nests interstratified between the slates. 
The manganese occurs in the contact of the slates with these 
layers. Usually the manganese is not co-extensive with the 
ironstone layers, but it is of considerable thickness, and it 
opens out into great nests ; usually the thickness is less as the 
extent is greater. Thus, at the mine of St. Cataline, the deposit 
extended 1,300 feet with a thickness of 2 feet, while in the 



300 



EARTHY AND OTHER MINERALS. 




MANGANESE DEPOSITS OF SOUTH-EAST SPAIN. 301 

mine Louisa the deposit was 150 feet in length with a thickness 
of 25 feet. 

In the layers the manganese and iron do not preserve a 
similar or equal thickness throughout their extent. One 
mineral presses out the other, so that one or the other often 
occupies the whole space between the under and overlying 
rocks. The two minerals, though so closely associated, are not 
mixed, but are kept distinct from each other, so that usually 
the iron does not contain manganese nor the manganese iron ; 
a natural arrangement which we have seen prevails elsewhere, 
and one that much facilitates the working of both minerals. 

The principal ores of manganese worked in this district are 
pyrolusite and psilomelane, wad and manganite seldom occur- 
ring. The best analysis shows 94 per cent, of oxide of man- 
ganese, the average quality ranging from 70 to 75 per cent. 
The thickness of the nests of manganese, with the underlying 
iron, ranges from 10 to 40 feet. The concessions are usually 
300 metres long and 200 metres broad, with vertical boundary- 
lines. The proportion of productive to unproductive ground 
in these concessions is very variable. The workings were some 
time ago all open to day, but as the ore is won the layers are 
followed downwards. The cost of getting and separating 100 
Ibs. of manganese is stated at from 2 to 3 reals, the minerals 
hand-picked, and the adhering clay, slate, or other substances 
separated from it. Manganese ores also occur near the Cape 
de Gata, the south-east point of Spain, and the southernmost 
point of the Sierra Algamilla. The mining district is about 35 
miles long by 1 6 miles broad. It has cup-shaped hills of trachyte 
and porphyry, which contain ores of manganese, lead, and copper. 
On the west side of these hills there are calcareous shales of 
Tertiary age, which are upheaved and broken by the trachytic 
and porphyritic rocks. In these latter rocks there are man- 
ganese ores of a quality of 70 to 90 per cent, of peroxides, but 
the deposits are so small in extent and thickness that it is 
scarcely possible to make the working of them pay. In the 
abrasion of these rocks, however, during long ages, the man- 
ganese has been separated from them, and has been gathered 



302 EARTHY AND OTHER MINERALS. 

into nests and layers in the Tertiary strata, which are frequently 
a calcareous conglomerate. Some of these deposits have an 
extent of 250 feet in length, 1 50 feet in breadth, and a thickness 
of 5 feet. They contain peroxide of manganese of from 75 to 
80 per cent. The strike of the beds here is from north-west to 
south-east and the dip north-east 25 degrees to 30 degrees. 

FRANCE. This country has been rich in manganese. The 
old mine of Romaneche, in the Department of Seine and 
Loire, has been worked for this mineral over a hundred years. 
It is situated on the eastern slope of a chain of mountains 
running north-north-east and south-south-west, composed of 




FIG. 73. SECTION OF THE DEPOSIT OF MANGANESE OF THE OLD MINE OF ROMANECHE, 

FRANCE. 

A A, Granite. B, Limestone. C, Manganese. D, Vein of Manganese. E, Greenish 

Clay. 

granite, limestone, and hard sandstones, as seen by the annexed 
sketch, fig. 7 3, which shows how the deposits were understood 
about a hundred years ago. 

There is first of all a thin vein or irregular bed of manganese 
in the granitic rock, and then, a little higher up, a much larger 
deposit, the main one, which is surmounted by what is near the 
surface a greenish clay, but which lower down becomes indu- 
rated. This mass was about 400 yards in length, and about 20 
yards at its greatest breadth. It extends from north-east to south- 
west, dying out at the extremities. It forms thus an irregular 
mass, accumulated in the bedding of the strata. It rises in places 



MANGANESE MINE OF ROMAN&CHE. 303 



above the soil, so that pro- 
bably it was only a portion 
of a much larger mass, the 
upper part of which had 
been denuded. The greater 
part of the mass was free 
from an admixture of other 
minerals, but in places 
there occurred fluor spars 
of a deep violet colour, and 
the cavities and fissures 
contained a reddish grey 
plastic clay. Through the 
kindness of M. Vital, of 
Rodez, Aveyron, Govern- 
ment Inspector of Mines for 
that district, I am able to 
give a plan of the workings 
on the two lodes or deposits, 
fig. 74, and also a detailed 
description by him of each 
lode as occurring about the 
year 1857. The lodes are 
still worked. 

' The lodes explored in 
the neighbourhood of Ro- 
maneche are three in num- 
ber the great vein, the 
little vein, and the mass sub- 
ordinate to the great vein. 
' The Great Vein has an 
easterly direction, north 
10 east, and dips to the 
east at an angle of about 
70; it is situated upon the 
border of a mass of greatly 
decomposed granite. To 



s 



Shaft Meteriers. 



Air Shaft. 



Vercheics Pit. 



Great Vein Shaft. 
Old Rectory Shaft. 



B I Mazoyer Shaft. 

fHy 

& HH! J esnin Shaft. 



Joesnin and Cadoz 
Shaft. 



304 EARTHY AND OTHER MINERALS. 

the south it distinctly penetrates the granite and ramifies. To 
the north it is lost in a great network which penetrates the 
oolitic limestones in contact with the granite. Between these 
two extremities its length is 320 metres = 349 yards. 

1 The Little Vein branches out from the great vein at 120 
metres =131 yards from its northern end. Its direction is 
north 35 east, and its dip is from 70 to 72 to the east. It 
is imbedded in the granite and has been followed about 530 
metres = 577 yards towards the south. 

' The veins consist of manganese oxide, barytiferous hydrate 
(prilomelane), quartz, fluor spar, sulphate of barytes, and oxide 
of iron. These minerals are mixed together in all proportions, 
and the mixture forms the mineral matter of the lodes. 

'The thickness of the Great Vein varies in the regular parts 
from 1-50 m. to 2 m. = 4 ft. 10 in. to 6 ft. 6 in., and that of 
the Little Vein from 3 ft. 3 in. to 4 ft. 10 in. 

'The portions near the junctions of the lodes were the most 
mineralised, and near here the Little Vein was about 6 metres 
thick = 6 1 yards, close to the surface. 

' The exploratory works have been sunk about 80 metres 
= 87 yards in the Little Vein, and about 36 metres = 39 yards 
in the Great Vein. The richness of the veins seems to diminish 
in depth, and the exploratory works are concentrated in the 
neighbourhood of the levels. The raw material yields about 
40 per cent, of commercial mineral. 

' The subordinate mass to the Great Vein consists of a layer 
nearly horizontal of argillaceous materials mixed with pebbles 
of a varied nature and of mineral blocks. This stratum runs 
along the roof of the Great Vein near the surface. It has been 
followed about 100 metres =109 yards, about 60 metres = 
62 yards wide, and 30 metres = 33 yards thick, and the raw 
material makes 75 per cent, of commercial mineral. 

'The veins were discovered in 1750 and were immediately 
worked. The mass was discovered in 1847, an d since then the 
principal works have been in it. 

'The works supply three qualities of minerals the rich 
65 and above, the medium 54 to 58, and the poor 45. 



MANGANESE DEPOSITS OF MISSOURI. 305 

'In 1881 the mines employed 182 men, with an output of 
10,870 tons French, equivalent to a value of 365,632 francs.' 

In the Cevennes manganese is found under similar minera- 
logical conditions, and the ore is characterised by being light 
and friable, and as dividing in irregular prisms. 

Manganese is also met with in what were the Departments 
of the Vosges and the Moselle, and a compact variety of grey 
ore has been produced in great quantities in the department of 
Dordogne, which has been known in commerce as Perigueux 
stone. 

In the Emma lode of the La Vidale mine of the Mines 
d'Asprieres, Aveyron, I have just noticed a nice illustration 
of the dependence upon or alliance with greenstone by man- 
ganese ore. As the lode passes through ordinary Silurian slate 
rocks it contains, in addition to copper and lead, a great thick- 
ness of blende ; but in its course of about ten yards through a 
band or dyke of greenstone the blende gives place to black 
oxide of manganese. 

AMERICA. Manganese ores are extensively raised in the 
United States. Pyrolusite and Psilomdane are found at Ben- 
nington, Brandon, Chittenden, Irasburg, and Monkton in 
Vermont, Conway in Maine, Plainfield in Massachusetts, 
and Salisbury and Kent in Connecticut. Wad or Bog man- 
ganese occurs at Blue Hill Bay, Dover, and elsewhere in 
Maine, and at Nelson, Gilmanton, and Grafton, New Hamp- 
shire j also at the mine La Motte in Missouri. Manganese spar 
is largely worked at Stony Mountain, near Winchester, New 
Hampshire. 

The sections, figs. 75 and 76, taken from Mr. Raphael 
Pumpelly's report on the iron ores of Iron Mountain and 
Pilot Knob, Missouri, illustrate the mode of the occurrence of 
the manganese deposits of that interesting mining region. 

These deposits 1 lie in strata that are considerably higher 
up in the series than those in which the iron ore deposits 
proper occur, and they are probably of Lower Silurian age. 

1 Geology of Pilot Knob and its Vicinity. By Raphael Pumpelly, United 
States Geological Survey. 

X 



;o6 



EARTHY AND OTHER MINERALS. 



Underlying the deposit of fig. 75 there is a bedded rock 
of fine grain which has in places the appearance of an indurated 




FIG. 75. MANGANESE DEPOSIT ON CUTHBERTSON HILL. 
M, Manganese Deposits. D P, Decomposed Porphyry. G P, Granitic Porphyry. 

sandstone, in others that of an altered porphyry. It contains 
numerous broad and flat cavities filled with an ochreous clay. 




FIG. 76. SECTION OF MANGANESE DEPOSIT ON BURFORD MOUNTAIN. 
M, Manganese Deposits. D P, Decomposed Porphyry. 

The manganese in the deposit lies in exceedingly ragged 
tabular masses. The analysis of this ore is as follows : 



Insoluble silicious matter 
Peroxide of iron . 
Manganese as protoxide 
Metallic manganese . 



0-44 
3'30 

68-02 



In section fig. 76, at Burford Mountain, which lies west of the 



MANGANESE DEPOSITS OF ARIZONA. 307 

above, we have a bedded deposit lying between decomposed 
porphyry above and below, of a pink colour, with the differ- 
ence that the ore is a manganiferous iron ore of a very supe- 
rior quality, and, it is said, is a remarkably fine ore for the 
manufacture of Spiegeleisen. An analysis shows it to contain 

Insoluble 8-54 

Peroxide of iron 68-30 

Manganese as protoxide .... 15-84 

Sulphur . . . . . . . 0-017 

Phosphorous acid . . . . . 0-012 

Equal to 

Metallic iron 47'8i 

Metallic manganese 12-32 

Sulphur 0-017 

Phosphorus 0-044 

These deposits are interesting as showing the similarity in 
the manner of the deposition of the manganese in the ancient 
felspathic rocks with that in which the mineral is deposited in 
the old Tertiary clays of Nassau, Germany, and the clays above 
the Carboniferous limestone, as shown in fig. 63. 

Among the Southern States the manganese mines of Cave 
Spring, Louisiana, were lately in successful working, producing 
about 1 6 tons of ore a day. 

Interesting deposits of manganese occur at the ' Lucky 
Cuss ' mine, Tombstone, Arizona. The country rock is a hard 
white limestone, in which the manganese ore bodies occur in 
' pipes ' or ' chutes,' which are of great depth, but do not 
extend far horizontally. One of these is nearly round in shape, 
loto 12 feet diameter. Another is a flat, oval-shaped mass, 
40 feet long by 3 broad. Another is of the same breadth but 
longer. Some of these ore bodies have been followed to a 
clepth of 100 feet without any signs of diminution in size. The 
ore is a rich oxide of manganese, containing about 10 per cent, 
of silica and 25 ounces of silver to the ton of ore. Small 
bunches of galena occur here and there throughout the masses, 
and these contain up to 200 ounces of silver to the ton of ore. 
Usually the more silica the manganese contains the richer it is 



308 EARTHY AND OTHER MINERALS. 

in silver, although an occasional mixture of manganese and 
lime spar shows a higher percentage. About 22,000 tons of 
ore had, up to May, 1882, been obtained from the mine at a 
cost of $10 a ton, the cost getting lower as preparatory work 
becomes finished. 

Small shipments have also been made from Canada. The 
Queen manganese mine of New Brunswick shipping in May, 
1882, a cargo of 105 tons. 

From the foregoing particulars it will be seen that origin- 
ally manganese was largely disseminated throughout the older 
rocks, into the cracks and veins of which it was subsequently 
gathered. That, as occurring in veins and lodes, it is not usually 
in sufficient quantity to pay for working. At a more recent 
period it seems to have been deposited contemporaneously 
with the strata, particularly in strata of a sandy nature and in 
the vicinity of porphyritic and felspathic rocks. The more 
recent deposits in Tertiary clays are derived from the denuda- 
tions of these older strata. It will also be seen that from the 
irregular nature of the deposits the mining must be of the 
cheapest character and the machinery of the most temporary 
nature compatible with safety. 



309 



CHAPTER XIX. 

CLASSIFIED LIST OF MINERAL SUBSTANCES. 

Purposes of the Chapter Abbreviations List of Simple Elements, 
divided into Metallic and Non-metallic Further divided into Seven 
Classes Oxygen Enumeration of Classes with Included Substances 
Table of Strata Conclusion. 

THE following list of minerals occurring in nature is intended 
chiefly to show the position occupied by those minerals which 
are described in this volume, and in that of Metalliferous 
Minerals and Mining. As far as possible the chemical com- 
position of each mineral is given or indicated. It need hardly 
be said that differences of opinion exist as to the precise order 
or succession in which mineral substances should be placed, 
depending upon an author's preference for one or another 
mode of grouping, according to chemical composition, or 
affinities, or upon crystallisation, or upon the behaviour of the 
various minerals under treatment. In the following list I have 
followed as nearly as I could the arrangement of Dana. The 
abbreviations used are: H. hardness; E. M., Earthy Minerals 
and Mining; M. M., Metalliferous Minerals and Mining. The 
whole of the materials of which, as far as we know, the crust 
of the earth is formed, is reducible to the sixty-four elementary 
substances enumerated in the following list : 

LIST OF ELEMENTARY SUBSTANCES WITH THE ABBREVIATIONS BY 
WHICH THEY ARE USUALLY KNOWN. 



Aluminium . Al. 
Antimony . Sb. 
Arsenic . As. 



Barium . . Ba. 
Beryllium . . Be. 
BISMUTH . . Bi. 



Boron . . . B. 
Bromine . . Br. 
Cadmium . . Cd. 



310 EARTHY AND OTHER MINERALS. 

LIST OF ELEMENTARY SUBSTANCES continued. 



Caesium . . Cs. 


LEAD . . . Pb. 


Selenium . . Se. 


Calcium . . Ca. 


Lithium . . L. 


SILVER . . Ag. 


Carbon . . C. 


Magnesium . Mg. 


Silicon . .Si. 


Cerium . . Ce. 


Manganese . Mn. 


Sodium . . Na. 


Chlorine . . Cl. 


MERCURY . Hg. 


Strontium . Sr. 


Chromium . Cr. 


Molybdenum . Mo. 


Sulphur . . S. 


Cobalt . . .Co. 


NICKEL . . Ni. 


Tantalum . . Ta. 


COPPER . . Cu. 


Niobium . . Nb. 


TELLURIUM . Te. 


Didymium . D. 


Nitrogen . . N. 


Thallium . . Tl. 


Erbium . . E. 


Osmium . . Os. 


Thorium . . Th. 


Fluorine . . F. 


Oxygen . . O. 


TIN ... Sn. 


Gallium . . G. 


PALLADIUM . Pd. 


Titanium . . Ti. 


GOLD . . . Au. 


Phosphorus . P. 


Tungsten . . W. 


Hydrogen . . H. 


PLATINUM . PL 


Uranium . . U. 


Indium . . In. 


Potassium . K. 


Vanadium . V. 


Iodine . . . I. 


Rhodium . . Rh. 


Yttrium . . Y. 


IRIDIUM . . lr. 


Rubidium . . Rb. 


ZINC . . . Zn. 


IRON . . . Fe. 


Ruthenium . Ru. 


Zirconium . Zr. 


Lantanum . La. 







These elements are broadly divided into metallic and non- 
metallic, the latter being fifteen in number, and the whole 
of them may be conveniently divided into the seven classes 
described in this chapter. It will be noticed that many of 
these elementary substances are very rare v and, so far, of more 
interest scientifically than commercially, the most abundant 
elements being silicon, oxygen, lime, magnesia, sulphur, 
with others described in this volume. Of oxygen, as it does 
not find a place among the gases occurring native, Class I., 
it may be well to say a few words here, unless indeed, 
from the correspondence it bears to sulphur in the way 
in which both these minerals combine with certain others, we 
place it in the same class as sulphur. It has a general relation 
to the whole of the other elements, all of them, excepting fluo- 
rine, combining with it to form oxides. Oxygen was discovered 
almost simultaneously, but independently, by Priestley and 
Scheele, Priestley in 1774 and Scheele in 1775. In 1778 
Lavoisier described the position occupied by oxygen in 
the atmosphere, and showed the changes that took place 



HARDNESS OF MINERALS. 3 I I 

when bodies burn in the air. He gave it the name 
of oxygen, from oxus, acid, and gennao, I generate, 
with reference to its property of forming acids in uniting 
with other elementary bodies. Combined with these, it is 
the most extensively diffused and abundant substance in 
nature, forming part of the atmosphere, of water, and of nearly 
all the substances of which the globe is composed. Its dis- 
covery is also taken as the date of the origin of true chemical 
science and theory. It may be obtained from the atmosphere 
as well as from other substances, but the material most used 
in its manufacture is the black oxide of manganese (page 287). 
Oxygen gas is without colour, smell, or taste. It is heavier 
than air ; the latter being 1,000, oxygen is 1,102 '6. It is essential 
to life and combustion, and combustion takes place with greater 
brilliancy and swiftness where it is present in excess. 

The degree of hardness assigned to the various minerals 
by the figures used in the description given of them will be 
understood by a reference to the following scale: 

1. Talc. 6. Adularia Felspar. 

2. Rock Salt. 7. Rock Crystal. 

3. Calcareous Spar. 8. Prismatic Topaz. 

4. Fluor Spar. 9. Corundum. 

5. Apatite. 10. Diamond. 

It will be noticed in the perusal of the following list and of 
the detailed description of substances given in this and the 
volume on metalliferous minerals, how recently, comparatively 
speaking, the true nature of many of them has been discovered ; 
that, notwithstanding the rapid progress which the sciences of 
chemistry and mineralogy have made during the last hundred 
and fifty years, they may still be taken, if not in their infancy, 
at least in a state of growth and progression. 

CLASS I. GASES. 

The gases are divided into 

i. Those consisting of or containing nitrogen, atmospheric 
air. 



312 EARTHY AND OTHER MINERALS. 

2. Those consisting of or containing hydrogen, carburetted 
hydrogen, phosphuretted hydrogen. 

3. Those consisting of or containing carbon or sulphur, 
carbonic acid, sulphurous acid. 

ATMOSPHERIC AIR. Composition : oxygen 21 percent, by 
weight, and nitrogen 7 9 per cent.,with a small quantity of carbonic 
acid. About 815 times lighter than water. Essential to life. The 
oxygen consumed by the breathing of animals and consumption 
of fuel is given back by vegetation. Pressure, about 15 Ibs. 
to the square inch. Encircles the earth to a height of about 
45 miles above the sea. 

NITROGEN. A colourless gas, without taste or smell, is 
lighter than air, as air being i, its specific gravity is 0-972. Is 
destructive to life, not by poisoning, but by suffocation. It 
does not combine readily with other substances, but it can be 
made to combine with oxygen and with hydrogen. When 
combined with the latter it forms ammonia. It may be pre- 
pared by passing air over red-hot copper, or by passing a 
current of chlorine through strong solutions of ammonia. 
Although of itself unable to support life or combustion, it 
forms a large proportion of the air we breathe. It is freely 
given off from various warm mineral springs. 

CARBURETTED HYDROGEN. Hydrogen does not exist un- 
combined in nature. Carburetted Hydrogen consists of carbon 
75 and hydrogen 25. It is nearly identical with the gas 
in ordinary use for lighting purposes, and it issues freely, and, 
as is too well known, with terrific results, from coal seams. 

PHOSPHURETTED HYDROGEN. Composition : phosphorus 
91-29, and hydrogen 871. Supposed to be the same as the 
luminous matter seen hovering over bogs and marshes. 

SULPHURETTED HYDROGEN. Composition : sulphur 94-2, 
hydrogen 5*8 ; of a putrid taste and smell. Common about 
sulphur springs and volcanoes. 

MURIATIC ACID, HYDROCHLORIC ACID. Composition : 
chlorine 97*26, hydrogen 2-74. Largely made for manu- 
facturing purposes. Is pungent in smell, and acrid to the 
skin. 



WATER. .313 

CLASS II. WATER. 

Water was first shown by Cavendish, in 1781, to be the 
product of the combustion of hydrogen and oxygen. Humboldt 
and Gay-Lussac afterwards demonstrated that the two gases 
unite strictly in the proportion of two volumes of hydrogen to 
one of oxygen, and that the water produced by their com- 
binations when in a state of vapour occupies two volumes. A 
series of experiments subsequently established the proportions 
by weight as hydrogen one part, and oxygen eight parts. 
Specific gravity i. At 32 it freezes, and as ice its specific 
gravity is lighter, being 0*916. In this form it assumes 
a blue or greenish colour. It crystallises in a rhomboidal 
form. As snow it crystallises in a variety of combinations. Its 
density is greatest at 39-1, and at temperatures below this it 
expands. It boils at 212, but its exact boiling-point is 
varied according to its degree of purity and the nature of the 
substances held in solution. It contains various proportions 
of atmospheric air, in which the proportion of oxygen is higher 
than in the air itself. In sea-water, there are solid substances 
amounting from 32 to 37 parts to 1,000. Of these, usually more 
than one-half is common salt, and four-fifths of the remainder 
magnesian salts, with sulphate and carbonate of lime, and 
traces of bromides, iodides, phosphates, and fluorides. These 
are most abundant in the Atlantic, and least in the Baltic Sea. 
An analysis of the water of the British Channel gives to 1,000 
parts : water 964-7, chloride of sodium 27-1, chloride of 
potassium 0*8, chloride of magnesium 3-7, sulphate of mag- 
nesia 2*30, sulphate of lime 1-4, carbonate of lime 0-03, with 
traces of the other minerals mentioned above. For other 
analyses of sea-water, see pp. 83, 90, 91. 

CLASS III. EARTHY MINERALS. 

1. SILICA and its varieties. See pp. 3 15. 

2. LIME and its varieties. See pp. 31 35. 

3. MAGNESIA and its varieties. See pp. 24 28. 

4. ALUMINA and its combinations. See pp. 16 24. 



314 EARTHY AND OTHER MINERALS. 

5. GLUCINA and its combinations. See p. 35. 

6. ZIRCONIA and its combinations. See p. 36. 

7. THORIA. See p. 36. 

BERYLLIUM, probably identical with glucinium. 



CLASS IV. CARBON AND COMPOUNDS OF CARBON. 
For the description of carbon and its combinations, 
diamond, graphite, jet, amber, bitumen, petroleum, &c., see 
p. 183- 

CLASS V. SULPHUR. 

See p. 232. 

SELENIUM. Selenium is allied to sulphur, and we have 
seen how it is present, together with that mineral, in several 
bodies. It was discovered by Berzelius in the year 1817, in 
the sulphur of the copper mine of Falun, which was employed 
in a sulphuric acid manufactory in Sweden. It is one of the 
rarest elements, but it occurs in minute quantities in several of 
the ores of copper, lead, silver, bismuth, tellurium, and gold ; 
found in Norway and Sweden, and also in the mines of the 
Hartz in Germany, as well as in the Sipan Islands. The pro- 
cess by which it is separated from its combinations with other 
substances is a very complicated one. It is, or was, extracted 
from a seleniferous ore of silver in Norway, and sold in little 
cylinders about three inches long, of the thickness of a goose- 
quill. 

CLASS VI. HALOID MINERALS. 

(Compounds of the earths and alkalies), with notices of some 
of their metallic bases. 

AMMONIA. Ammonia takes its name from Ammonia in 
Libya, where a salt was extracted, named after the region sal 
ammoniac, and from which ammonia has usually been obtained. 
In a state of purity ammonia is a gas, of which the liquor is a 
solution in water. Ammonia is produced by the destructive 
distillation of organic matters containing nitrogen. For, as we 
have already seen, it is a combination of nitrogen and hydrogen. 



POTASH, RUBIDIUM, CAESIUM. 315 

Sal Ammoniac. Composition : ammonia 33*7, chlorine 
66-3. Formerly obtained largely in Africa from soot of the fires 
made from the dung of camels ; obtained also from bones and 
hoofs and horns, and latterly from the ammoniacal liquor 
obtained in the making of coal gas. It has varieties 

Mascagnine, Sulphate of Ammonia. Composition : sul- 
phuric acid 53*3, ammonia 22*8, water 23*9 ; yellowish grey or 
lemon yellow colour. 

Phosphate of Ammonia, found in guano. 

Struvite, a phosphate of ammonia and magnesia. 

POTASH OR POTASSA. COMPOUNDS OF POTASSIUM. 
Potassium, one of the simple elements, produced from potash, 
in 1807, by Sir Humphrey Davy. It has, when first pro- 
duced, a white colour with a shade of blue. It is solid at 
an ordinary temperature, but yields like wax under pressure. 
It oxidises immediately on exposure to the air, and soon loses 
its colour, and is covered with a dull film of oxide. It is 
brittle at 32, and at this temperature has crystallised in cubes ; 
at 70 it is semi-fluid, and becomes liquid at 150. It can be 
distilled at a low red-heat, when it forms a green-coloured 
vapour. At 60 its specific gravity is '0865. It appears to 
have, of all bodies, the greatest affinity for oxygen. Exposed 
in thin slices to the atmosphere it passes into a white matter, 
which is the protoxide of potassium, or POTASH. 

Nitre, Nitrate of Potash, Saltpetre. Composition : potash 
46-56, nitric acid 53*44. Occurs in India, and appears as an 
efflorescence from the soil in Egypt and Spain, where consider- 
able quantities are collected. It is artificially produced in 
various European countries in nitriaries, or nitre-beds, from 
the decomposition of the nitrates of lime and magnesia, which 
are common in the neighbourhood of the beds, and also from 
refuse animal and vegetable matter. 

Chloride of Potassium, Sylvine. Occurs with salt at Salz- 
burg. 

RUBIDIUM, CESIUM. These two metals resemble each 
other and potassium so closely that prior to the year 1860 i, 
they were mistaken for that metal. About the time stated 



3l6 EARTHY AND OTHER MINERALS. 

they were discovered by Bunsen and Kirchhoff, by means of 
spectrum analysis. They were first detected in the water of 
Durkheim, but subsequently they were found in many springs 
and micaceous and in other of the older rocks. Rubidium is 
a white metal, which rapidly oxidises and gives off a green 
vapour. Both together they are separated from potassium, 
caesium being subsequently separated from rubidium. 

SODA. Soda is a combination of sodium (see p. 61) with 
hydrogen and oxygen. It comprises the following salts, which 
are all more or less soluble, in which they differ from those of 
potash. H. under 3 ; specific gravity under 2-9. 

Sulphate of Soda, Glauber Salt. Composition: soda 19*3, 
sulphuric acid 24/8, water 55*9. White to yellowish white ; 
taste, saline and bitter. Differs from Epsom salts in its coarser 
crystals and yellow colour under the blow-pipe. Occurs in a 
cave on Hawaii, one of the Sandwich Islands, and is prepared 
from sea-water. First discovered by a German chemist named 
Glauber. 

Nitrate of Soda. See p. i oo. 

Natron, carbonate of soda. Composition: soda 2-18, 
carbonic acid 15*4, and water 6*28; but usually mixed with 
chloride of sodium, and other salts. Occurs in Egypt in the 
soda lakes, and in the valley of Bahr-bela-ma, thirty miles west 
of the Delta. A variety named Trona occurs between Tripoli 
and Fezzan, in Africa, where it forms a thin layer under the soil, 
which yields several hundred tons yearly. Is also found in 
saline lakes associated with common salt. 

Chloride of Sodium, common salt. See p. 61. 

Borate of Soda, Borax. Seep. 102. 

LITHIA. Is a rare alkaline oxide, whose metallic base, 
LITHIUM, was discovered by Arfwedson in the year 1818. The 
metal was obtained by Sir Humphrey Davy by the voltaic 
decomposition of lithia. It is white, resembling sodium, and 
is very oxidisable. 

BARYTA. For Barium, Baryta, and their combinations, 
see p. 103. 

STRONTIA. Strontium is one of the simple elements. It 



STRONTIA, MAGNESIA SALTS. 317 

is a white metal, denser than oil of vitriol. It resembles 
barium ; it has not a high lustre, is fusible with difficulty, and 
is not volatile. It was first obtained by Sir Humphrey Davy 
in 1808. By exposure to the air, or by contact with water, 
it is changed to Strontia, which consists of 

Strontium 84-54 . . . or I atom 44 
Oxygen 15*46 . . . or i atom 8 



Strontia derives its name from Strontian, a mining village of 
Argyllshire. It is not abundant in nature. 

Sulphate of Strontia, Celestine. Composition : strontian 
56-4, sulphuric acid 43-6. H. 3- to 3-5. Specific gravity 4. 
Brittle, columnar, crystallises in rhombic prisms, clear white, 
with a tinge of blue. Used in the manufacture of fireworks for 
producing a red colour. 

Carbonate, of Strontia, Strontianite. Composition: strontia 
70*2, carbonic acid 29*8. H. 3*5 to 4. Specific gravity 3*6 to 
3*72. Greenish white, grey, and yellowish brown. First dis- 
tinguished from carbonate of barytes in 1790 by Dr. Crawford. 
Occurs at Strontian in starlike and fibrous groups, associated 
with galena. Also used in the manufacture of fireworks. 

LIME. See p. 31 and p. 109 et seq., apatite or phosphate 
of lime. 

MAGNESIA SALTS. Sulphate of Magnesia, Epsom Salts. 
Composition: magnesia 16-3, sulphuric acid 32-5, water 50-2. 
Occurs in fibrous crusts or botryoidal masses of a white colour, 
also in fine small rhombic crystals. Found at Epsom in Surrey, 
at Seidlitz, and various places in Europe ; in the Cordilleras of 
Chili, also in South Africa. 

Magnesite, Carbonate of Magnesia. Composition : magnesia 
47*6, carbonic acid 47*6. Occurs in fibrous plates and in 
minute acicular crystals of a white, yellow, or grey colour. 
Found in magnesian limestones, and used sometimes for the 
manufacture of sulphate of magnesia. 

Brucite. Composition : magnesia 69*0, water 31*0. After 



3l8 EARTHY AND OTHER MINERALS. 

exposure it often contains carbonic acid. Colourless to greyish 
white. Translucent, pearly, soluble in acids. 

Nemelite is a fine fibrous variety with a silky lustre. Com- 
position: magnesia 62-0, protoxide of iron 4/6, water 28-4, car- 
bonic acid 4*1. Resembles asbestos. 

Boracite.Borate of Magnesia. Composition : magnesia 30-0. 
boracic acid 7*0. White or grey colour, with a vitreous lustre. 
H. =7. Specific gravity 2-97. Occurs with gypsum and com- 
mon salt. Other minor varieties are 

Nitrate of Magnesia. Occurs in limestone caverns, asso- 
ciated with nitrate of lime. 

Polyhalite, brick-red in colour, composed of sulphates of 
lime, potash, and magnesia, with water. 

Rhodizite, like boracite, but tinges the blow-pipe flame red. 
Found in Siberia with red tourmaline. 

Wagnerite. Composition : phosphoric acid 43*32, fluorine 
n'35, magnesia 37*64, and 7*69 magnesium, varied with 3* to 
4' 5 iron peroxide, and i to 4 lime. 

See also p. 24, et seq. 

ALUMINA, SALTS OF. i. Native Alum. See p. 107. 

2. Alunite, alum stone. Composition : alumina 37*1, sul- 
phuric acid 38-5, potash n, water 13. Colour white, greyish, 
or reddish, vitreous lustre. Crystals rhombohedral, trans- 
parent to translucent. H. = 4. Specific gravity 2-58 2-75. 
A variety found in Hungary is hard enough for the manufacture 
of millstones. 

Websterite, another form of sulphate of alumina, also called 
alumnite. 

Wavellite. Composition : alumina 33*8, phosphoric acid 
34*9, water 26*6, fluoride of aluminium 4*6. Occurs in small 
half-round masses adhering to surface of rocks, of a white or 
yellowish or brown colour, with a pearly lustre. Fischerite is 
closely allied ; has a dull green colour. 

Turquoise. Composition : alumina 44*5, phosphoric acid 
30*9, oxide of copper 3*7, protoxide of iron 1*8, water 19*. 
Occurs in reniform masses ; colour bluish green, with a waxy 
lustre. H. == 6. Specific gravity 2*6 3. Found in a moun- 



SALTS OF ALUMINA, BROMINE. 319 

tainous district near Nichabour in Persia ; said to occur in 
veins which traverse the mountains. Receives a fine polish, 
and is much valued as a gem. 

Hydrate of Alumina, Gibbsite. Composition : alumina 
65-6, water 34-4, with traces of phosphoric acid. Is softer 
than chalcedony, which it resembles. Other varieties are 

Amblygonite. Composition : phosphoric acid, alumina, and 
lithia. 

Childrenite. Composition : phosphoric acid, alumina, and 
water. 

Chiolite resembles cryolite. 

Cryolite occurs in snow-white masses, melts in the flame of 
a candle ; is a fluoride of aluminium and sodium, is quarried 
to a considerable extent in Greenland, and is used as an ore 
of aluminium. 

Diaspore, or dihydrate of alumina. Found in granular 
limestone in the Ural Mountains, where it occurs in irregular 
lamellar prisms with a fine* cleavage. 

Fluettite. Composition : fluorine and aluminium. Occurs 
in the mines of Cornwall in minute forms. 

Lazulite. Composition : alumina 357, magnesia 9*3, silica 
2-1, protoxide of iron 2 '6, and water 6*1. Occurs in compact 
masses, and occasionally in oblique crystals of a fine azure 
blue colour, nearly opaque, with a vitreous lustre. Found in 
clay-slate at Salzburg, and elsewhere. 

Mellite, or honey stone, has a resinous appearance, of a 
honey yellow, and may be cut with a knife. Composition : 
alumina 14*32, mellic acid 40-53, and water 45*15. A rare 
mineral, found in Bohemia, Thuringia, and Moravia. 

Associated with the haloid minerals just enumerated are 
the elements CHLORINE, BROMINE, IODINE, and FLUORINE. I 
have referred to chlorine at p. 61, and fluorine at p. 106, of 
this volume. 

BROMINE. Was first observed in the year 1826 by M. 
Balard, of Montpellier. Its name is significant of its bad and 
disagreeable smell. It is found in very small proportions in 
sea-water, in the form of bromite of sodium or magnesium ; 



320 EARTHY AND OTHER MINERALS. 

also in the water of the Dead Sea, and in saline springs 
generally. The principal source whence bromine, as an article 
of commerce, is derived, is the wells of Theodorshall, near 
Kreuznach, Germany. It is closely allied to chlorine in many 
of the properties of the latter. 

IODINE. M. Courtois, of Paris, in preparing carbonate of 
soda from kelp, discovered this substance in the year 1811. 
Its chemical properties were subsequently made known by 
Clement, Davy, and Gay-Lussac, and it has formed a valuable 
contribution to medical or surgical resources. It is found in 
sea-water, but more abundantly in seaweed and sea plants 
generally. It has also been obtained from an ore of silver at 
Albaradon, in Mexico. 

CLASS VII. METALS AND METALLIFEROUS MINERALS. 

CERIUM. This name was given to the metal by Hisinger 
and Berzelius from Ceres. It is not an abundant metal, neither 
is it used in the arts. It is found in a number of minerals 
near the celebrated mines of Falun, in Sweden. It has been 
obtained as a powdery mass of a dark chocolate brown colour, 
which gave a grey metallic trace under the burnisher. 

YTTRIUM. Is only known to exist with oxygen in YTTRIA, 
an earth discovered in 1794 by Professor Gadoline, near 
Ytterby, in Sweden. YTTRIA is white in colour, but generally 
tinged by the presence of manganese. It is insoluble in water, 
and infusible, except at a great heat. When dissolved in 
muriatic acid it- gives out chlorine gas, which fact is taken as 
shewing one property of a metallic oxide. 

LANTANUM. The oxide of this metal was discovered about 
fifty years since in the cerite of Bastnas in Sweden, by Mosander, 
and said to form two-fifths of the oxide of cerium, which, by the 
ordinary process, is extracted from that metal. The abstrac- 
tion of the new metal alters but little the properties of cerium, 
and it lies, so to speak, concealed in that mineral, and it is 
this circumstance that led M. Mosander to give it the name 
lantanum. 



TANTALUM. YTTROCERITE. 321 

TANTALUM. This metal appears to have been first dis- 
covered in the year 1801, in a black-coloured mineral belonging 
to the British Museum, which was supposed to have been brought 
from Massachusetts, and which had been named Columbian. 
In the following year M. Ekeberg found a new metal, which he 
named tantalum, in two Swedish minerals which he named 
Tantalite and Yttrotantalite. Ekeberg gave the name tantalum 
to the new metal on account of the insolubility of its oxide in 
acids, in allusion to the legend or fable of Tantalus. The 
mineral was found to be identical with that of the British Museum 
named Columbian. Berzelius obtained tantalum in the form of 
a black powder which could be washed and dried, and which 
gave an iron-grey metallic lustre under the, burnisher. It 
burned in the air below a red heat, and yielded Tantalic Acid, 
in which state it is present in several minerals, especially iron 
and manganese. 

The above four metals are of little or no use in the arts, 
and are chiefly interesting in a scientific point of view. 
Although found in minerals in other countries, notably North 
America, it will be seen that they occur chiefly in Sweden, where 
their nature seems to have been first accurately ascertained. 
They seem to be intimately associated one with the other, and 
altogether with other minerals, in which combinations the 
following varieties have been observed. 

YTTROCERITE. Composition : oxide of cerium 18*2, yttria 
9-1, fluoric acid 25-1, and lime 47*6. It occurs in a massive 
form of a violet blue colour, ranging to grey and white. H.=: 
4 5- Specific gravity 3-4 3-5. It is found in Finbo and 
Brodbo, near Falun, in Sweden, and in Massachusetts and New 
York, United States of America. Its varities are 

/ Composition : peroxide of cerium 84-21, hydrofluoric 
Fluocerine . . ] acid 10-85, wa ter 4-95. Yellow to brown, vitreous or 
( resinous. From Finbo, Sweden. 

/Composition: lantanum oxide 52-9, carbonic acid 21-1, 
I water 26. White or yellowish ; granular, earthy, and 
' I in small tabular crystals. Bastnaes in Sweden, and 
* Sehigh in Pennsylvania. 

Y 



322 EARTHY AND OTHER MINERALS. 

(Composition : protoxide of cerium 60 -o, carbonic acid 
23 '6, fluoride of calcium ii'Si, water 2-4, with lanta- 
num and didymium. Brownish yellow to red. Found 
in the emerald mines of the Musso valley in New 
Granada. 

MONAZITE. Composition: cerium protoxide 25*0 to 37*0, 
lanthanium oxide 23-0 to 27-0 (i 8 thorina), phosphoric acid 28, 
tin oxide 2, lime 1*5, with small portions of manganese and 
magnesia. Flesh red to reddish brown, with a vitreous lustre. 
H.=5. Specific gravity=4'8 5*1. Resembles sphene, an ore 
of titanum, but is distinguished by its brilliant, easy, transverse 
cleavage. Found at Miask, in the Urals, and in Connecticut 
and New York States, in North America. 

CRYPTOLITE, which is a combination of phosphorus with 
the oxide of cerium, occurs in minute six-sided prisms, in con- 
nection with the apatite deposits of Norway described in 
Chapter VII. 

ALLANITE. Composition : variable, but usually containing 
silica 30*0 to 35*0, alumina and iron peroxide 12*0 to 18*0, 
protoxides of cerium n to 24, lanthanium 2-0 to 8'o, iron 4-0 
to 21*0, manganese o* to 3*5, lime 2- to 12*0, yttria 0^3 to 4*0, 
and magnesia 0-4 to 5-0. In colour black or brown, with an 
imperfect metallic lustre and a green or greenish-grey streak. 
H.= 6. Specific gravity 3-2 to 37. Found in Greenland, 
Norway, Sweden, the Urals, and in various localities of the 
United States of America. Its allied minerals or varities are 

, . f An ore of cerium resembling orthite. From Boden, 

" 1 Saxonv. 
* . ( Consists of silica and alumina, with the oxides of iron, 

' \ cerium, lantanum, and also lime. 

/ Composition : protoxide of cerium with didymium and 
Cerite . . . j lantanum 72-0, silica 22, water 6, with iron protoxide 

' and lime. 

Orthite . . . Similar in composition, but occurring in acicular crystals. 
Pyrorthite ( An im P ure ortm ' te containing carbon, and will burn, 

' ( hence its name, pyr, fire, and orthite. 

These varieties are found in the same localities as 
allanite. 



PYROCHLORE. 



323 



PYROCHLORE. Composition : very complex. Analyses 
of the mineral from Miask in Russia, gave niobic acid mixed 

vith titanic and tungstic acid 62*0 to 6^0, lime 10*0 to 13*0, 
oxide of cerium and thoria 6*0 to 13*0, fluoride of sodium 7*0. 
In a sample from Norway, yttria, iron, zirconia, lithia and 
uranium occur. Found near Brevik and Fredericksvarn, 

Norway, and near Chesterfield in Massachusetts. Minor 
varieties of the foregoing combinations of cerium, yttrium, lan- 
tanum and tantalum with each other, and with other minerals, 
are the following : 

A combination of titanium with zirconia and cerium, in 
brown and black crystals. Miask, in the Urals. 

A. columbate of yttria with titanic acid and oxide of 
uranium ; brownish black with reddish streak ; occurs 
in splinters. Arendal in Norway. 

Similar in composition to euxenite, but crystallising in 
secondaries to a square prism. Cape Farewell, Green- 
land. 

Composition: varied; usually yttria 36-0 to 51-0, silica 
25-0 to 29-0, protoxide of cerium with lantanum 
5-0 to 17*0, glucina o-o to 12-0, protoxide of iron io-o 
to 15. Black with greenish grey streak; vitreous. 
Kragero in Norway, and Finbo and Ytterby, Sweden. 
/ Like the next following, polymignite : black, massive, 



/Eschynite . . I 



Euxenite 



^ergusonite 



Gadolinite . 



Polycrase 



Polymignite 



Rutherfordite 



Satnarskite . 



Tschefkinite 



Hit- 



and in thin linear crystals ; occurs with orthite. 
tero in Norway. 

Composition: protoxide of cerium 5-00, yttria 11-50, 
zirconia 14* 14, peroxide of iron 12-20, peroxide of 
manganese 2-70, lime 4- 20, titanic acid 46-30. Occurs 
in long prismatic crystals, broad and striated vertically. 
Iron black, dark brown streak, semi-metallic appear- 
ance. Fredericksvarn in Norway. 

{Contains about 58 per cent, of titanic acid with 10 per 
cent, of lime, with portions of cerium and yttrium. Is 
found in the gold mines of Rutherford County, N.C., 
United States of America. 

r Composition : niobic acid 56-0, protoxide of iron 15-0 to 
16-0, oxide of uranium 14 to 17-0, yttria with lime and 
( magnesia 8-0 to ii-o. Velvet black in colour, with a 
1 strong metallic appearance. Ilmen Mountains, Siberia. 
( Similar to Gadolinite. Velvet black ; a silico-titanate of 
( cerium. Ilmen Mountains. 



324 



Xenotime 



Yttrotantalite 



EARTHY AND OTHER MINERALS. 

Composition: yttria 62-82, phosphoric acid 37-18, with 
3-39 phosphate of iron, and traces of fluoric acid. Crys- 
tallises in square prisms ; yellowish brown. Lindes- 
1 naes and Hittero in Norway, and Ytterby in Sweden ; 
\ also in Georgia, United States of America. 
^Composition: tantalic acid 57-9 to 60-0, tungstic acid 
i-o to 8-0, yttria 20-0 to 38-0, lime 0-5 to 6-0, uranium 
peroxide 0-5 to 6-0, and peroxide of iron 0-5 to 3-5. 
J Occurs in indistinct four or six-sided prisms, and also 
' \ in grains and lamellae ; in thin splinters translucent ; 
has three varieties in colour : dark or brown, yellow 
. or yellowish grey, and black. Is found at Ytterby in 
Sweden. 

URANIUM. This is a rare metal in nature. It is of a steel 
white colour, and in dry air it does not oxidise on exposure at 
ordinary temperatures. It is derived from Pitchblende and 
Uranite. It is used in glass-making, the uranous oxide im- 
parting a fine black and the uranic oxide a beautiful yellow to 
the glass. In enamelling they yield a fine orange colour. 
Compounds of uranium are now also used in photography. 
We have also seen how its oxides enter into the composition 
of the minerals just described. As just stated its ores are 

PITCHBLENDE. Composition : protoperoxide of uranium 
8478 and oxygen 15*22, but varied by proportions of lead, mag- 
nesia, iron, arsenic, silica, with occasionally vanadium and 
selenium. Colour, grey brown to velvet black, with a dull 
or sub-metallic lustre. H. 5-5. Specific gravity 6 '47. Dis- 
solves slowly when powdered in nitric acid. Found in the 
tin mines of Cornwall, in the lead and silver mines of Erze- 
birge, also in Connecticut, United States of America. Its 
varieties are 

| Resembling pitchblende, found near the junction of 
I trap and syenite on the north shore of Lake Superior. 
t An ore of similar description, but containing io| per 
I cent, of water. 
/ A peroxide of uranium of a light yellow colour, easily 



Coracite 



Eliasite 



Uranic ochre 



powdered ; associated with pitchblende in the localities 
named. 



URANITE, Uran Mica. Composition : peroxide of uranium 



TITANIUM. 325 

62*6, phosphoric acid 15 '5, lime 6*2, water 15*7 ; bright yellow 
to green, with a pale yellow streak. Occurs in short square 
prisms. H. 2, 2*5. Specific gravity 3 3-6. Fine examples 
of green crystalline forms occur in Cornwall. Found also 
in the mines of the Erzgebirge and near Autun and Limoges, 
France. Its varieties are 



T j 7 \ A- su lp na te of uranium of an emerald green colour. 

Saniarskite,Q\so f Composition : oxide of uranium 1 4-0 to 17*0, yttria with 
called Uran- I lime and magnesia 8'O to iro, protoxide of iron 
tantalite and \ 15 to 1 6, niobic acid 56, with portions of lime and 
Yttrollmenite 1 magnesia. See also p. 323. 

TITANIUM. In a metallic state sometimes found as small 
cubic crystals, of a bright copper colour, adhering to the slag 
of iron furnaces. Their density is 5-3 and they are harder than 
quartz. As a metal, it was discovered by McGregor of Corn- 
wall in the year 1791. It was afterwards observed by Klaproth, 
who gave it the name of titanium. In nature it occurs in com- 
bination with oxygen, and so combined its ores are with dif- 
ficulty fusible before the blow-pipe. The ores are 

RUTILE. Composition, titanium 6i'o, oxygen 39, some- 
times containing a little iron, when it has been called Nigrine. 
Of a reddish brown to red colour. Occurs in eight, ten, and 
twelve sided prisms. H.= 6 6-5. Specific gravity 4-15 to 
4*25. Is largely associated with the apatite deposits of Norway 
in gneissic rocks (Chapter VII.), with specular iron at the 
Orisons. Found also at Yriex in France, the Urals, Brazil, 
Scotland, and the United States of America, sometimes beauti- 
fully associated with quartz, p. 7. Used in colouring porcelain. 
Its varieties are 

r Same composition as rutile. Occurs in slender octa- 
ase ' ' ' \ hedrons of a brown colour, and nearly transparent. 

/ Same composition as rulile, but with 1-4 to 1-5 of perox- 
1 ide of iron. Occurs in thin brown hair-like crystals ; 
' I said to be found near Snowdon and Tremadoc, North 
' Wales. 



326 EARTHY AND OTHER MINERALS. 

SPHENE. Composition: titanic acid 40-4, silica 3 1*3, lime 
28-3, with o* to 5' of protoxide of iron in the darker varieties ; 
brown, yellow, green, opaque to semi-transparent, with resinous 
or adamantine lustre. H. = 5 5-4. Specific gravity, 3-2 3-6. 
Occurs in crystals from a quarter of an inch to two inches long in 
granitic gneiss, mica, syenite, or granular limestone. Found in 
several localities in Scotland, Norway, Sweden, Saxony, Russia, 
France and America. The name is taken from the Greek 
sphen, wedge, in allusion to the shape of the crystals. Its 
varieties are 

i Containing much protoxide of manganese, and of a flesh 
Greenwite . . | red colour> St Marce i i n Piedmont. 

/Composition: titanic acid 27-8, silica 28-8, lime IQ'5, 

yttria 9-3, alumina 6-9, peroxide of iron 7-7. Of a 

Yttrthtitanit* blackish brown colour with a reddish tinge, and grey 

brown streak, and vitreous or resinous lustre. Occurs 

\ near Arendal, Norway. 

/ Of a similar composition to sphene, but of a black shining 
Schorlomite , < appearance. From the Ozark Mountains, Arkansas, 

' where it occurs near gadolinite. 
Perofskite . . A titanite of lime. 
P rrhite ( Is a niobiate of zirconiawith iron and uranium. Found 

' \ near Mursinsk in Siberia, and at the Azores. 
Titantite . . Is simply a dark variety of sphene. 

Warwickite occurs in prismatic crystals of an iron grey to 
brown colour, and a red tarnish. It is distinguished by con- 
taining 20 per cent, of boracic acid. 

By referring back to the description of the ores zirconia 
and yttria, it will be seen that titanium enters into the com- 
position of ^Eschynite, ^Erstedite, Polymignite, and others ; also 
of ilmenite titanic iron. M. M., p. 248. 

NIOBIUM. Niobium is a rare metal, whose properties are 
not yet much understood. It seems allied to or associated 
with tantalum and titanium. 

TIN. For a description of tin and its ores see M. M., 
pp. 162 186. 

ARSENIC. See pp. 253 257. 



TUNGSTEN. THALLIUM. 327 

COBALT. See pp. 258 271. 

ANTIMONY. See pp. 275, 281. 

BISMUTH. See M. M., pp. 280 i. 

TUNGSTEN. Tungsten, Swedish heavy stone, as tungstic 
acid is present in several minerals. In combination with iron 
and manganese it forms Wolfram, or tungstate of iron and 
manganese (M. M., p. 249) ; in combination with lead it forms 
tungstate of lead (M. M., p. 189), and with lime tungstate of 
lime. Composition: tungstic acid 7*8, lime 19-06; tungstic 
ochre, forming a yellow powder on other ores of tungsten. 
It is present also in the minerals pyrochlore and yttro- 
columbite. 

MOLYBDENUM. See pp. 272 276. 

TELLURIUM. See M. M., p. 286. 

LEAD. See M. M., pp. 187 237. 

THALLIUM. This metal was discovered as recently as the 
year 1861 by Mr. Crookes in the matter deposited in the 
flue of a pyrites burner. In a metallic state it closely resem- 
bles lead in its physical properties. When fresh cut the newly- 
exposed surface shows a bluish white lustre, which quickly 
tarnishes upon exposure, and it is best preserved under water. 
It is soft, being easily indented with a finger-nail, and it melts 
below a red-heat. The presence of the metal is shown by the 
appearance of a vivid green line on the spectrum. It dissolves 
readily in nitric and sulphuric acids, giving out hydrogen. 
The soluble salts of the metal are colourless, and act as strong 
poisons. 

VANADIUM. Is a metal of the rarest occurrence in nature. 
It was discovered in iron prepared from the iron ore of Taberg, 
Sweden, in the year 1830 by Sefstrom, and it was afterwards 
obtained in larger quantity from the slag of the ore. In its 
properties it bears considerable resemblance to chromium. 
As vanadic acid it occurs in 

Vanadinite, or vanadate of lead (M. M., p. 189), discovered 
by Mr. Johnson, of Wanlockhead. 

Vanadate of Copper , found in the Ural Mountains. 



328 EARTHY AND OTHER MINERALS. 

Vanadate of Lime, of a brick-red colour, shining lustre, and 
a foliated structure. 

CHROMIUM. Was discovered in the mineral now known 
as Chromate of Lead (M. M., p. 189) in the year 1797 by 
Vauquelin. It has since been obtained from other minerals, 
more especially chromate of iron (M. M., p. 249), and it is 
from this ore chiefly that the many beautifully coloured prepa- 
rations used in arts and manufactures are obtained. It forms 
two compounds with oxygen oxide of chromium and chromic 
acid. 

NICKEL. For nickel and its ores, see M. M., pp. 281 
284. 

MANGANESE. See pp. 282 308. 

IRON. See M. M., pp. 246 276. 

ZINC. See M. M., pp. 238 245. 

CADMIUM. This is a very rare mineral, of which only one 
ore is known, named Greenockite. It is of a honey or orange 
yellow colour, high lustre, and nearly transparent. It is found 
at Bishopstown in Renfrewshire. Composition : cadmium 77*6, 
sulphur 22*4. Cadmium is also associated in small propor- 
tions with blende and calamine, ores of zinc. 

INDIUM. A metal recently discovered by means of spec- 
trum analysis, associated with zinc ores. A soft white metal 
resembling cadmium. 

MERCURY. See M. M., pp. 277280. 

COPPER. See M. M., pp. 114 161. 

SILVEE. See M. M., pp. 81 113. 

GOLD. See M. M., pp. 32 80. 

PLATINUM. SeeM. M., pp. 284, 285. 

PALLADIUM. See M. M., p. 285. 

IRIDIUM. See M. M., p. 285. 

OSMIUM. Osmium is closely associated with iridium, from 
which it is separated by mercury. At first it is a black powder 
without metallic lustre; when further treated it becomes a 
white metal, not so brilliant as platinum, and is easily reduced 
to powder. When first obtained from the amalgam it is very 



RHODIUM. RUTHENIUM. 329 

combustible, and the mass burns away, being converted into 
the volatile oxide, or osmic acid. Five oxides of this metal 
are given, but osmic acid is the only one that is formed 
directly. Its density is 10. 

RHODIUM. Rhodium was obtained by Wollaston in the 
ore of platinum. An ore from Brazil contained 0-4 per cent., 
and an ore from another locality has yielded as much as 3 per 
cent, of rhodium. Rhodium, when fully prepared, is a white 
metal with a density of about 1 1 . In a pure state it is not 
affected by acid, but when alloyed with platinum, bismuth, 
lead, or copper it dissolves with those metals. The solutions 
of the metal have a beautiful red colour, whence its name from 
p68ov, a rose. 

RUTHENIUM. A rare metal allied to the last. 

The substances enumerated and described in the foregoing 
pages are distributed throughout the strata of the earth's crust , 
as given in the following table. 

TABLE OF STRATA. 

Q O/ Recent. 

POST PLIOCENE. 
NEWER PLIOCENE. 
OLDER PLIOCENE. 
W | MIOCENE. 
H EOCENE. 

Lower, Middle, and Upper. 
, Chalk. 

>, CRETACEOUS . . . " , . ; . ] JJPJf* Greensand - 

' Lower Greensand. 
P. WEALDEN . (^ealden 



OOUT, 



(.Purbeck Beds. 
4 Portland Oolite. 
U P per * j Kimmeridge Clay. 



i Cornbrash. 

Forest Marble. 
Lower . . . .4 Bath or Great Oolite. 

I Stonesfield Slate. 

v Inferior Oolite. 

("Upper Lias. 
LIAS \ Marlstone. 

(.Lower Lias. 

f Rhaetic Beds. 
TRIAS ^Keuper (New Red Marl). 

(Hunter (New Red Sandstone). 



330 



EARTHY AND OTHER MINERALS. 



TABLE OF STRATA continued. 



PERMIAN 



CARBONIFEROUS 
SERIES 



'Upper . 
Middle . 

Lower 

Coal Formation 



Carboniferous or Moun 
tain Limestone . 



DEVONIAN (OLD| 
RED SAND- \ Devonian Beds 
STONE) . / 



f Silurian, or Upper Silu 
rian 



Cambro, or Lower Silu 
rian 



Cambrian 



Laurentian 



. Dark Red Sandstones and Marls. 
Magnesian Limestones and Marls 

("Conglomerates, Breccias, and Red 
' I Marls. 

( Upper Coal Measures. 
. ^ Middle Coal Measures. 

( Lower Coal Measures. 
Millstone Grit. 

f Limestone and Shales- 

J. Carboniferous Limestone. 
' (^Calcareous Sandstone. 

( Upper Devonian. 

j Middle Devonian. 

( Lower Devonian., 

/Tilestones. 

I Upper Ludlow Beds. 

I Aymestry Limestones. 

J Lower Ludlow Beds. 

I Wenlock & Woolhope Limestones. 
Denbigh Grits and Wenlock Shale. 

I Tarannon Shale. 

V Upper Llandovery. 

I Lower Llandovery. 

) Balaand Caradoc Beds. 

1 Llandeilo Beds. 

^Arenig Beds. 

(Tremadoc Slates. 
Lingula Flags. 
Harlech and Llanberis Slates and 
Grits. 
Longmynd Rocks. 
f Fundamental Gneiss of the North - 
J West of Scotland and Laurentian 
( Rocks of Canada. 



It will be observed that the first six classes of minerals have 
a much wider range through time then have the distinctively 
metalliferous minerals. It may also be noticed generally that 
while the latter are more strictly confined to lodes, veins, and 
contact deposits, the former occur in beds, large deposits in 
beds, and in irregular accumulations in strata and in previously 
formed cavities. 




INDEX. 



ACT 

A CTINOLITE, 27 

-^"*- Adularia felspar, 24 

/Erschinite, 323 

^Erstedite, 326 

Agates, 9 

Alabandine, 285 

Allanite, 322 

Alum, native, 107 ; shale, 107 ; works, 
1078 

Alumina, 14 ; salts of, 318 

Aluminium, 14 

Alunite, 318 

Amber, 230 

Amblygonite, 319 

Amethyst, 8 

Ammonia, 314 ; phosphate of, 315 ; 
sulphate of, 315 

Anatase, 325 

Anhydrate, 105 

Antimony, 275 ; history of, 275 ; 
native, 275 ; ores of, 276 ; arsenical, 
277 ; red, 278 ; sulphuret, 276 ; 
white, 278 ; in Algiers, 281 ; in 
America, 281 ; in Borneo, 280 ; in 
New South Wales, 281 ; uses of, 
279 

Apatite, 1 10 ; in Canada, 112; in Nor- 
way, 119 ; Aqua Marine, 22 

Argentine, 31 

Arsenic, 233 ; ores of, 253 ; in 
America, N. & S., 257 ; in Austria, 
257 ; in British Islands, 255 ; in 
France, 256 ; in Germany, 256 ; in 
Italy, 257 ; in Russia, 257 ; in 
Spain, 257 ; manufacture of, 255 ; 
uses of, 254 

Asbestos, 27 

Asbolane, 259 

Asparagus stone, no 

Asphaltum, 204; of Auvergne, 216; 



of Euphrates and Tigris, 220 ; 
Seyssel, 216 ; Val de Travers, 216 ; 
Spain, 219 ; Trinidad, 221 ; atmo- 
spheric air, 312 

Augite, 26 

Aventurine felspar, 24 ; quartz, 8 

Azure, 260 



BALA limestone, 32 
Barbadoes. tar, 221 

Barium, 103 

Baryta, 103 

Barytes, 104 ; production of, 104 

Basalt, 30 

Basanite, 13 

Bauxite, 17 

Berthierite, 277 

Beryl, 20 22 

Bitumen, 204 ; in chalk of Auvergne, 
Val de Travers, 214; Seyssel, 216; 
on Gneissic rocks of Sweden, 212 

Bituminous coals, 8 ; of Autun, 
| 213; Bovey Tracey, 211 ; Brecken- 
ridge, 223 ; Feymoreau, 212 ; Flint- 
shire, 208 ; New Brunswick, 222 ; 
Torbane Hill, 210 

Bituminous shales of Germany, 216 

Blood stone, 13 

Bodenite, 322 

Bone beds, 145 

Boracic acid, 102 

Boracite, 317 

Borax, 102 

Boron, 102 

Boulangerite, 277 

Brazil, gem deposits of, 20 

British diamonds, 7 

Bromine, 319 

Bronzite, 26 



332 



INDEX. 



BRO 



Brookite, 325 
Brucite, 317 
Burmese oil, 221 



CADMIUM, 328 
Caesium, 315 

Calcareous tufa, 32 

Calcium, 31 

Canada, apatite deposits of, 1 12 

Cannel, 208 

Canton, corundum of, 17 

Caoutchouc, 204 

Carbon, 204 

Carbonate of lime, 31 

Carboniferous limestone, 33 

Carnelian, n 

Catseye, u 

Celestine, 416 

Cerine, 322 

Cerite, 322 

Cerium, 320 

Ceylon, gem deposits of, 22 

Chalcedony, 9 

Chalk, 32 

Chemical composition of limestones, 
37 

Chert, ii 

Childrenite, 319 

Chiolite, 319 

Chloanthite, 259 

Chloride of sodium, 62 

Chlorine, 61 

Chlorite, 24 

Chromate of lead, 328 

Chromium, 328 

Chrysoprase, n 

Clays, composition of, 38 ; China clay, 
41 ; of the coal measures, 39 ; Devo- 
nian, 39 ; Drift, 40 ; London clay, 46 ; 
millstone grit, 39 ; Permian, 46 ; of 
Bovey Tracey, 44 ; Cornwall, 41 ; 
North of England, 48 ; North 
Wales, 48 ; Shropshire, 54 
Coal, bituminous, of Autun, 213 ; 
Bovey Tracey, 211 ; Breckenridge, 
223 ; Denbighshire, 208 ; Fey- 
moreau,2i3 ; Flintshire, 208 ; New 
Brunswick, 222 ; Torbane Hill, 210 ; 
S. Wales, 208 

Coal-measures sandstone, 31 
Cobalt, 258 ; arsenate of, 259 ; arse- 
nite of, 259 ; bloom, 259 ; earthy, 
259 ; radiated white, 259 ; sulphate, 
259; tin white, 259; in America, 
270; Austria, 270; Cornwall, 260; 



GAS 

N. Wales, 261 ; France, 270; Ger- 
many, 269; Norway, 263 ; Sweden, 
264 

Common opal, 13 

Coracite, 324 

Cornwall, granites of, 29 

Corundum, 17 

Crednerite, 285 

Cryolite, 319 

Cryptolite, 322 

Crystalline limestone, 32 

Crystals, formation of, 6 104 



T^ARWIN, CHAS., DR., 98 

U Dead Sea, water of, 91 

Devonian limestone, 33 

Diallage, 26 

Diallogite, 285 

Diamond, the, 183; depositsof Borneo, 

185; Brazil, 185; India, 184; S. 

Africa, 186; mining, 184, 186, 

189 

Diamonds, remarkable, 191 
Diaspore, 319 
Dioritic greenstones, 30 
Donegal, granite of, 28 

pLEMENTARY substances, list 

*-* of, 309 

Eliasite, 324 

Emerald, 20 

Epsom salts, 317 

Erythrine, 259 

Euxenite, 323 



T^ELSPAR, 23 ; aventurine, 24 
- 1 - Felspathic granite, 28; and 

porphoritic rocks, 28, 39 
Fergusonite, 312 
Ferruginous quartz, 8 
Fibrous gypsum, 105 
Fire opal, 13 
Fleches d'Amour, 8 
Flint, 9 
Fluorine, 100 
Fluor spar, 106 
Foliated talk, 25 



f ADOLINITE, 323 

^ Galway, gneissic rocks of, 28 

Gasses, 311 



INDEX. 



333 



GEO 

Geokronite, 277 

Gibbsite, 319 

Girasol, 13 

Glauber salts, 416 

Glucina, 35 

Glucinium, 36 

Gneissic Rocks, 28 

Graphic granite, 28 

Graphite (see Plumbago), 192 

Greenland, asbestos in, 27 ; zirconia 

in, 36 

Greenovite, 326 
Gypsum, 105 



HARLEQUIN Opal, 13 
Hauerite, 285 

Hausmannite, 285 

Heliotrope, 13 

Hornblende, 27 

Hornstone, n 

Hyacinth, 36 

Hyalite, 13 

Hydrogen, carburetted, 312 ; sul- 
phuretted , 312; phosphuretted , 
312 

Hydrophane, 13 

Hypersthene, 26 



TCELAND, Boracic Lagoons of, 
J- 103 ; decomposition of rocks in, 

39 ; spar, 32 
Iodine, 320 
Indium, 328 



JARGON or Jargoon, 36 
Jamesonite, 277 
Jasper, 13 
Jet, 202 
Johannite, 325 



T/" EILHAUITE, 326 
-** Kilbrickenite, 277 
Kobbolds, 258 
Kobellite, 277 



T ANTANUM, 320 
"-* Lantranite, 321 
Liassic limestone, 34 
Ligniform asbestos, 28 



Lime and limestone, 31; Bala and 

Llandeilo, 32 ; carboniferous, 33 ; 

Devonian, 33 ; magnesium, 34 ; 

liassic, 34 ; Oolitic, 34; chemical 

composition of, 37 
Linnaeite, 259 
Lithia, 316 
Lithium, 316 
Llanwddyn, great stone quarry of, 

30 
Lydian stone, 13 



MADAGASCAR, rock crystals 
of, 7 

Magnesia, 24; apatite, no 

Magnesite, 417 

Magnesium, 24 

Malacolite, 26 

Manganese, ores of, 284 ; carbonifer- 
ous limestones of Derbyshire, 290 ; 
of Shropshire, 290 ; in Devonian 
strata of Devon and Cornwall, 288 ; 
of North Wales, 289; of United 
States of America, 305 ; of Canada, 
308 ; Britain, 288 ; France, 302 ; 
Germany, 292 ; Italy, 298 ; Spain, 
299 

Manganite, 284 

Maps, Canadian apatite deposits, 1 14 ; 
Norwegian, 120; Welsh phosphorite, 
130 ; manganese district of Spain, 
300 

Marble, of Anglesea, 33 ; Carrara, 34 ; 
Derbyshire, 33 

Marmolite, 26 

Mascagnine, 315 

Mica, 24 

Micaceous granite, 28 

Mineral pitch, 204 

Minerals, scale of hardness, 311 

Mines, principal referred to Berwyn 
(phosphorite), 133 ; Borrowdale 
(graphite), 192; Brazil (gems), 20, 
185; Brevik (zirconia), 36; Canada, 
apatite, 1 13 ; Carrickfergus, salt, 79 ; 
Cessena, sulphur, 240 ; Cheshire, 
salt, 73 ; De Beers, diamonds, 188 ; 
Eckholmen, molybdenite, 274 ; 
Elbingerode, manganese, 293 ; Foel 
Hiraeddog, cobalt, 261 ; Glad- 
hammar, cobalt, 265 ; Golconda, 
diamonds, 184 ; Muso, emeralds, 22 ; 
Nant Uchaf, manganese, 289 ; Rio 
Tinto (pyrites), 248 ; Romaneche 
manganese, 302 ; Seyssel, asphal- 



334 



INDEX. 



MIS 

turn, 214; Sicily, sulphur, 236; 

Steeterwasen, manganese, 295 ; St. 

Marcel, manganese, 298 ; Val de 

Travers, asphaltum, 216; Vuggens, 

apatite, 119 
Mispickel, 254 
Molybdenite, 272 
Molybdenum, 272 ; America, 275 ; 

Austria, 274; Cumberland, 373; 

Eckholmen, 274 ; Germany, 274 ; 

Mount Sorrel, 273 ; Norway, 274 
Molybdic ochre, 273 
Monazite, 322 
Moonstone, 24 
Moroxite, no 
Mountain cork, 28 
Mountain leather, 28 
Muriatic acid, 312 
Muscovy glass, 24 



"NJ APHTHA, 205 

*^ Nemelite, 318 

New Red Sandstone, 31 

Niobium, 326 

Nitrate of potash, 315 ; soda, 100 

Norfolk, flints of, 11 

Norway, apatite mines of, 119; 
cobalt mines of, 263 ; granitic and 
gneissic rocks of, 28 ; zirconia, in, 
36 

OOLITIC limestone, 34 
Opal, 13 

Oriental amethyst, 19 
Orpiment, 254 
Orthite, 322 
Osmium, 328 
Oxygen, 310 



PALAGONITE, 39 

-*- Pargasite, 27 

Parisite, 322 

Peloconite, 285 

Peterhead, granite of, 28 

Petroleum, 205 ; history of experi- 
ments with, 207; Barbadoes, 221 ; 
of Bovey Tracey, 211; Canada, 
227 ; Caspian Sea, 220 ; Cuba, 222 ; 
Columbia, 222 ; Flintshire, 209 ; 
Germany, 217; India, 220; Italy, 
219; Roumania, 219; Spain, 219; 



South America, 228 ; United States 
of America, 207, 223 

Phosphate of lime, 109 ; discovery 
of in coprolites, in ; general com- 
position, no; production and con- 
Sumption of, in ; in Great Britain, 
19; deposits upon Canada, 112; 
Carolina, 170 ; Belgium, 152 ; Eng- 
land, 147; France, 152, 157, 167; 
Germany, 160 ; N. Wales, 130 ; 
Russia, 157; Spain, 142; various 
islands, 176 

Phosphoric acid, no 

Phosphorite, no 

Pitch Lake of Trinidad, 221 

Pitch mineral, 204 

Plagionite, 272 

Plumbago, 192; of Ceylon, 196; of 
Great Britain, 192 ; United States 
of America, 199 

Plumosite, 277 

Polycrase, 323 

Polyhalite, 314 

Polymignite, 323 

Porcelain, jasper, 13 

Potash or potassa, 315 

Potassium, 315 ; chloride of, 315 

Potstone, 25 

Precious opal, 13 

Precious serpentine, 26 

Psilomelane, 284 

Pyrites, 245 

Pyrochlore, 323 

Pyrolusite, 284 

Pyrosthite, 322 



QUARRIES, references to Bar- 
row-on-Soar(Lias), limestones, 
34 ; Caen, calcareous freestone, 34 ; 
Carrara marble, 35 ; Llanwddyn 
grey building stone, 30 ; North 
Wales limestone, 33; Penmaen- 
mawr greenstone, 30 ; Portmadoc 
greenstone, 30 

Quartz, 7 

Quartzose granite, 28 



"D ADIATED gypsum, 105 
-^ Rangoon oil, 220 
Realgar, 254 
Red opal, 13 
Rhodium, 329 



INDEX. 



335 



RHO 

Rhodizite, 318 

Rocks, composition of, into the com- 
position of which silica and alumina 
largely enter, 15 

Romeine, 278 

Roselite, 259 

Rose quartz, 8 

Rubidium, 315 

Ruthenium, 329 

Rutherfordite, 323 

Rutile, 325 



SAL AMMONIAC, 315 
Samarskite, 323, 325 

Sapphire, 17 

Salt, common, 62 

Salt Deposits of Africa, 90; of 
America Louisiana, 96 ; Michi- 
gan, 96 ; Missouri, 96; Nevada, 97 ; 
America, South Pacific coast, 98 ; 
Patagonia 90, 98 ; of Asia Caspian 
Sea, 90 ; Caucasus, 90 ; Crimea, 90; 
Indus, the, 92 ; Palestine, 90 ; Persia, 
91 ; of Austria, Dalmatia, 88 ; Istria, 
88 ; Salzberg, 85 ; Wieliezka, 86 ; of 
France, 81 ; of Germany Anhalt, 
83, Hanover, 84 ; Wiirtemburg, 84 ; 
of Great Britain and Ireland 
Ashby Wolds, 76; Carrickfergus, 
79; Cheshire, 70; Droitwich, 74; 
Durham, 77 ; of Italy, 83 ; Rou- 
mania, 89; of Russia Archangel, 
Astrachan, Orenburg, Solikamsk, 
89; of Spain Burgos, 82; Car- 
dona, 81 ; Ebro, the, 82; Salt garden 
of, 83 ; of Switzerland, 81 

Salt industry, history of in Great 
Britain, 63 

Salt mines, modes of working, 72, 
80, 86 

Salt Strata, 70, 75 ; sections of, 77, 80, 

87.93 
Sard, ii 

Sea-water, analyses of, 83, 91 
Selenium, 314 
Senarmonite, 278 
Serpentine, 25 
Silica, 3 
Silicon, 3 
Smoky quartz, 8 
Soda, 61 ; borate of, 102 ; carbonate 

of, 416 ; nitrate of, 100 ; sulphate 

of, 416 
Sodium, 61 ; chloride of, 62 



wis 

Stalactite, 32 

Stalagmite, 32 

Steatite, 25 

Steinmannite, 278 

Strata, table of, 329 

Strontia, 316 

Strontium 316 

Struvite, 315 

Sulphur, native, 232 ; deposits of in 
Greece, 242 ; Iceland, 243 ; Italy 
Cessena, 240 ; Sicily, 233 ; made 
from pyrites, 246; mining, 240, 
241 

Sylvine, 315 



HPALC, 25 

Tantalum, 321 
Thallium, 327 
Thibet, tincal trade of, 102 
Thoria, 36 
Thorite, 36 
Thorium, 36 
Tincal, 102 
Titanite, 326 
Titanium, 8, 325 
Topaz, 19 ; false, 8 
Touchstone, 13 
Triplite, 285 
Tschefkinite, 323 
Tungsten, 327 
Turquoise, 318 



TTRANIC ochre, 324 
U Uranite uran mica, 324 
Uranium, 324 
Uran vitriol, 325 



VANADATE of copper, 327 
lime, 327 
Vanadinite, 327 
Vanadium, 327 



WAD, 285 
Wagnerite, 318 
Warwickite, 326 
Water, 313 
Wavellite, 318 
Websterite, 318 
White augite, 26 
Wiserite, 285 



of 



336 



XEN 



VENTOTIME, 324 

A 



\7ELLOW quartz, 
A Yttria, 320 
Yttrium, 320 
Yttrocerite, 321 



INDEX. 



Yttrotantalite, 324 
Yttrotitanite, 326 



7AFFRE, 260 
^ Zinkenite, 278 
Zirconia, 36 



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