A HANDBOOK
TO THE
MINERALOGY
CORNWALL AND DEVON
T R U R 0 :
PRINTED BY HEARD AND SONS,
BOSCAWEN STREET.
HANDBOOK
MINERALOGY
OF
CORNWALL AND DEVON,
WITH INSTRUCTIONS FOE THEIR DISCRIMINATION, AND COPIOUS
TABLES OF LOCALITIES,
J. H. COLLINS, F.G.S.,
VN
LECTURER AND ASSISTANT SECRETARY TO THE MINERS' ASSOCIATION
OF CORNWALL AND DEVON;
SECRETARY TO THE KOYAL CORNWALL POLYTECHNIC SOCIETY;
ASSOCIATE OF THE KOYAL GEOLOGICAL SOCIETY OF CORNWALL,
AND OF THE ROYAL INSTITUTION OF CORNWALL, &C., &C.
TRURO:
HEARD AND SONS.
LONDON:
LONGMANS, GREEN, READER, AND DYER.
1871.
SCIENCES
ROBERT WERE FOX, F.R.S.,
THE DISCOVERER OP THB
ELECTRICITY OF MINERAL LODES IN CORNWALL,
AND OF MANY CORNISH MINERALS,
(WHOSE OBSERVATIONS EXTEND OVER MORE THAN HALF A CENTURY),
THIS
HANDBOOK TO THE
MINERALOGY OF CORNWALL AND DEVON
IS DEDICATED, BY
HIS SINCERE ADMIRER AND MOST OBEDIENT SERVANT,
THE AUTHOR.
229974
PREFACE.
This Handbook is the product of the few hours of brief
leisure of a busy life.
It is intended primarily as a Work of Reference for the
Student, the Mine Agent, and the Working Miner : that such a
work has been much needed will be conceded by all.
The Author cannot hope to have altogether escaped errors ;
and no doubt omissions and faults are not wanting.
The faults are his own ; but he trusts there are also some
excellencies, since he has received valuable assistance from those who
have been well acquainted with the subject for many years.
His thanks are especially due to Robert Were Fox, Esq.,
F.R.S.; Robert Hunt, Esq., F.R.S ; Professor Warington W.
Smyth, F.R.S.; Wm. Jory Henwood, Esq., F.R.S.; Professor A.
H. Church; Richard Pearce, Esq., F.G.S.; and many other gentle-
men, who have favoured him with information as to localities, &c.
FALMOUTH, September, 1871.
LIST OF WORKS CONSULTED.
EEPOKTS OF THE KOYAL GEOLOGICAL SOCIETY or CORNWALL, Yols. I. to VII.
REPORTS OF THE ROYAL INSTITUTION OF CORNWALL, 1838-1870.
REPORTS OF THE ROYAL CORNWALL POLYTECHNIC SOCIETY, 1833-1870.
TRANSACTIONS OF THE DEVONSHIRE ASSOCIATION.
A MANUAL OF MINERALOGY, TRURO, 1828?
AN ELEMENTARY INTRODUCTION TO THE KNOWLEDGE OF MINERALOGY, by WM.
PHILLIPS, 1823.
A MANUAL OF MINERALOGY, by BROOKE and MILLER, 1852.
MANUAL OF THE MINERALOGY OF GREAT BRITAIN AND IRELAND, by R. P.
GREG and W. G. LETTSOM, 1854.
A MANUAL OF MINERALOGY, by J. NICOL, 1849.
A GLOSSARY OF MINERALOGY, by H. W. BRISTOW, 1861.
THE MINERALOGIST'S DIRECTORY, by T. M. HALL,
A SYSTEM OF MINERALOGY, by J. D. DANA, 1868.
JOURNAL OF THE CHEMICAL SOCIETY,
CHEMICAL NEWS.
GEOLOGICAL MAGAZINE.
PHILOSOPHICAL MAGAZINE, &c., &c.
LIST OF ABBREVIATIONS OCCASIONALLY
EMPLOYED.
B., etc., for Blowpipe and other "dry " reactions.
Comp. ,, Chemical Composition.
Loc. ,, Localities.
Obs. ,, Observations.
OF „ Oxidizing Flame.
RF „ Eeducing Flame.
Co. „ Nitrate of Cobalt (in Solution.)
Sol. „ Soluble.
Insol. ,, Insoluble.
HC1. „ Hydrochloric Acid.
H2SO4 „ Sulphuric Acid.
HNO3 „ Nitric Acid.
KHO „ Caustic Potash (in Solution.)
Fus. „ Fusibility.
C. „ Charcoal.
Micro ,, Microcosmic Salt.
Soda „ Carbonate of Soda.
H. „ Hardness.
G. ,, Specific Gravity.
CONTENTS.
PART I.
'PAGE.
DEDICATION y.
PREFACE vii.
LIST OF "WORKS CONSULTED viii.
LIST OF ABBREVIATIONS ix.
TABLE OF CONTENTS x.
ERRATA xi.
CHAPTER I. — INTRODUCTORY 1
CHAPTER II. — DETERMINATIVE
TABLE I. — REACTIONS IN MATRASS 3
II. — REACTIONS IN OPEN TUBE
III.— REACTIONS ON CHARCOAL WITHOUT FLUXES 5
IV.— REACTIONS WITH COBALT 6
Y. — REACTIONS ON CHARCOAL WITH FLUXES 6
VI. — REACTIONS WITH BORAX BEAD 6
VII. —REACTIONS WITH MICROCOSMIC SALT 8
VIII.— FLAME COLORATIONS 10
IX.— REACTIONS WITH SOLVENTS 10
X. — GROUP I. — PULVERULENT 12
II.— FOLIACEOUS 13
III.— CAPILLARY 14
IV.— SAPID 15
V — MALLEABLE 16
VI.— PLASTIC 16
VII.— COLOUR AND STREAK BLUE 16
VIII. — COLOUR AND STREAK GREEN ... 17
IX.— COLOUR AND STREAK RED,
YELLOW, OR BROWN 18
X.— COLOUR VARIOUS, STREAK DARK,
H. BELOW 5 20
XI. — COLOUR VARIOUS, STREAK DARK,
H. 5-6 22
XII.— COLOUR VARIOUS, STREAK LIGHT,
H. BELOW 5 23
XIII. — COLOUR VARIOUS, STREAK LIGHT,
H. 5-6 25
XIV.— COLOUR VARIOUS, H. 6 AND
UPWARDS 26
XV. — COLOUR VARIOUS, COMBUSTIBLE
OR VOLATILE
CHAPTER III.— DESCRIPTIVE
NOMENCLATURE OF CORNISH MINERALS
TABLE OF THE ELEMENTS
CHAPTER IV.— SYSTEMATIC
SYSTEM I.— CHEMICAL
II. — ECONOMICAL
III. — MIXED
IV.— CRYSTALLOGRAPHIC
CHAPTER V.— DISTRIBUTIVE
LIST OF MINES, &c., CORNWALL
LIST OF MINES, &c., DEVON ^
CHAPTER VI. — PARAGENETIC ....
PART II.
ALPHABETICAL LIST OF MINERALS IN CORNWALL AND DEVON
PLATES, WITH DESCRIPTIONS
ADDENDA
LIST OF SUBSCRIBERS ...
ERRATA.
P. 12, Pt. II., col. 2, Loc., line 10. For Carharrack read Carharrack, St. Just.
P. 34, Pt. II., col. 1, Loc., line 18. For Tin read Cassiterit*.
P. 71, Pt. II., col. 1, line 23. For Kerargyrite read Kerat*.
A HAND-BOOK
TO THE
MINERALOGY OF
CORNWALL AND DEVON,
PART I.
CHAPTER I.
INTRODUCTORY.
A perfect definition is proverbially a very difficult, if not impossible, thing to
produce. The definition of a mineral is no exception, but one of the best runs
as follows:— "A mineral is any natural, homogeneous body, inorganically
produced." This definition is defective, inasmuch as it excludes coal, as well
as bog iron ore and some other substances, usually described as minerals j but if
the third character be not too rigidly applied it is tolerably correct.
The student having obtained a new specimen is naturally desirous to know
what its properties are. He will then desire to determine whether any similar
mineral has been described before. Next he will wish to know how to arrange it
with his other specimens, as well as where it has occurred before ; and, finally,
he will endeavour to ascertain the conditions of its occurrence. A division of
the Science of Mineralogy into the following five sections (as defined on p. 70,
Part II.) would therefore seem to be tolerably natural.
SECTION 1. Determinative.
„ 2. Descriptive.
„ 3. Systematic.
,, 4. Distributive.
,, 5. Paragenetic.
In this "Handbook" only a very brief outline of these various branches can
be given. Such an outline may, however, prove sufficient for many miners and
amateurs, and it may also serve as a convenient introduction to larger and more
complete works for those who desire to pursue the subject. For special and
detailed instruction in the use of the blowpipe the author would recommend
"An Introduction to the Use of the Mouth-Blowpipe," by T. Scheerer and
H. F. Blandford (Williams and Norgate, 1864), or the large work of Professors
Plattner and Muspratt, published by Messrs. Churchill.
A list of the apparatus used for the experiments described in this Handbook
is appended. Those marked thus, (*), are essential ; for the others an ingenious
student will usually be able to devise substitutes.
* 1. Blowpipe (Dr. Black's form is convenient and cheap).
* 2. An oil-lamp with flat wick, or a thick candle.
3. A spirit lamp.
* 4. Several pieces of charcoal.
* 5. Small glass tabes, open, and sealed at one end.
* 6. Borax.
* 7. Carbonate of soda.
* 8. Microcosmic salt.
* 9. Solution of nitrate of cobalt.
10. A small mortar of porcelain, or, much better, of agate or jasper;
2 CHAPTER XL— DETEEMINATIYE.
11. Brass forceps, with, platinum points.
12. Small steel-faced hammer and anvil.
13. Three-sided file, finely cut, for trying the hardness of minerals, cutting
glass tubes, &c.
* 14. A magnet.
* 15. A pocket magnifying glass.
16. Several watch-glasses.
17. Several test tubes.
18. Potassic bisulphate.
19. Boric acid.
20. Fluor spar.
21. Gypsum.
22. Oxide of copper.
23. Metallic lead, tin, copper, and iron, in thin plate or foil, and fine wire.
24. Bone ash-
25. Test papers — litmus or turmeric, and Brazil wood.
26. Distilled water.
27. Sulphuric acid.
* 28. Nitric acid.
* 29. Hydrochloric acid.
* 30. Ammonia in solution.
31. Caustic potash in solution.
* 32. Thin platinum wire.
33. Platinum foil.
34. Scale of hardness.
35. Scale of fusibility.
36. Penknife.
37. Contact goniometer.
CHAPTER II.
DETEKMINATIVE.
To determine the nature of an unknown mineral specimen it will be advisable
to adopt a system, and to adhere closely to it, for some time at least. Supposing
such a specimen to be placed in the hands of the student he should examine it
carefully, noting down the results of his examination according to the instruc-
tions contained in this chapter.
A large number of minerals occur, at least occasionally, in more or less regular
geometrical forms termed "crystals." These have been grouped into six
systems of crystallization," for convenience of study (see "Crystallography,"
p. 38, Part II.) It is no part of the purpose of this work to explain the sub-
science of crystallography;* but a great deal may be learnt by a careful
comparison of the specimen under examination with the figures on Plates I. to
X., with their explanations. If amorphous, or occurring in imitative forms, it
should also be noted.
A portion of the specimen should now be powdered for examination according
to the tables I. to X. While doing so a good opportunity is afforded for
noticing its cleavage and fracture, and determining its " Hardness " and other
PHYSICAL CHAKACTERS.
Its peculiar OPTICAL CHARACTERS, as colour, lustre, &c., should be at the same
time carefully noted, after which the student may proceed to test its CHEMICAL
CHARACTERS with the aid of the tables given.
These observations may very well be made in the order indicated below. Most
of the terms used are specially explained in another part of the work.
* Those who wish to follow up this delightful part of the subject will do well to
procure Nicol's "Manual of Mineralogy," Naumann's "Elemente der Mineralogie," or
some similar work.
CHAPTER II.— DETEEMINATIVE.
1. FORM—
!£?' } See Crystallography, p. 38.
2. PHYSICAL CHARACTERS other than form —
Cleavage, see p. 34.
Franglbility or Tenacity, } See p* 48'
Hardness, see p. 54.
Specific Gravity, see p. 94.
Magnetism, see p. 66.
Electricity, see p. 42.
3. OPTICAL CHARACTERS—
Colour, see p. 35.
Streak, see p. 98.
Lustre, see p. 65.
Diaphaneity, see p. 41.
Phosphorence, see p. 77.
Fluorescence, see p. 47.
Refractive Power.
Polarization.
4. CHEMICAL CHARACTERS—
Fusibility, see p. 49.
Solubility, see p. 94.
Taste, see p. 100.
Odour, see p. 72.
Adhesion to tongue.
Touch, see p. 102.
5. BLOWPIPE REACTIONS, see p. 18.
The specimen to be examined by the aid of the following tables should be
selected as free as possible from foreign matter and reduced to a coarse powder,
in a mortar or otherwise. It should then be subjected to the experiment?
detailed on p. 18, Part II. , and the results compared with the following tables,
which are applicable to substances of artificial production, as well as to
minerals.
TABLE I.— REACTIONS IN MATRASS.
BXP 1. — Heat a small portion in a matrass (see p. 18).
A. The substance turns black, and gives off pungent odours and much
moisture. Organic matter is indicated.
B. The substance changes colour, but no moisture or sublimate is evolved —
a. From white, yellow, grey, or brown, to black. The carbonates of iron,
manganese, and some other substances behave thus. Carbonate of
iron (Chalybite) becomes strongly magnetic ; peroxide of iron
(Hematite) is black while hot, but dark reddish-brown when cold.
b. From orange-red to brown while hot, again orange-red on cooling.
Potassic bichromate and some other chromates and bichromates
behave thus.
c. From yellow or pink to reddish-brown while hot, yellow when cold,
fusible with a strong heat ; oxide of lead is probable.
d. From yellow to deep orange-red while hot, lemon-yellow when cold.
Chromate of potash or some other chromate is probable.
e. White or pale yellow to a stronger yellow while hot, losing colour
again on cooling. Oxide of zinc or oxide of tin is indicated.
f. White to deep orange or reddish-brown while hot, yellow when cold,
fusible at a white heat. Oxide of bismuth is probable.
Many other substances change colour on heating, but most of them give off
moisture or a sublimate at the same time, and are therefore included in other
parts of this table.
O. The assay decrepitates, some anhydrous substance is indicated. When the
powder is very fine this reaction is not often observed. Among minerals
CHAPTER II.— DETERMINATIVE.
WOLFRAM and BLENDE often decrepitate strongly; of artificial substances
CHLORATE OF POTASH and NITRATE OF LEAD are good examples.
D. Water is given off, and deposited on the sides of the tube.
a. The assay melts at first, gives off much water, and finally re-solidifies.
Salts containing water of crystallization are indicated. Among
minerals Melanterite and Kalinite (alum) are good examples.
b. Gives off moisture without melting or swelling up. Many hydrates
or hydrous carbonates behave thus. Those of the heavy metals often
become much darker at the same time. Among minerals Malachite,
Chessylite, and Kaolin are good examples. The first two turn nearly
black ; the third remains white.
c. The quantity of water may be inconsiderable, and given off at a low
temperature. This is often water of absorption, taken up by the
substance from the air.
In all cases the moisture should be tested with " test paper." If acid,
some volatile acid, such as SULPHURIC or NITRIC, is indicated. If
alkaline, AMMONIA is present.
E. The assay fuses more or less readily, but gives off little or no water.
In such cases, while strongly heated, a fragment of charcoal should be dropped
in. A deflagration will indicate a NITRATE, PER-NITRATE, CHLORATE, or
PER-CHLORATE. This reaction is rarely to be expected when exainining a mineral
substance.
F. Gases and vapours other than steam are given off. (These will rarely be
observed in this experiment with mineral substances.)
a. The gas re-lights a glowing splint of wood. Oxygen is indicated from
CHLORATES, NITRATES, PEROXIDES, &c. The former are often
fusible; peroxides will be usually infusible.
b. An odour of burning sulphur is noticed. Sulphurous anhydride,
from SULPHATES and other bodies containing sulphur.
c. The gas is brownish or reddish. NITRATES and NITRITES are indicated.
d. The gas is colourless and without odour, but if conducted into "lime-
water" renders it turbid. Carbonic anhydride fromCARBo
e.g., CALCITE, ARAGONJTE, DOLOMITE, &c., among mineral
substances.
e. The gas is without colour and has but little odour, but burns with a
blue flame. Carbonic oxide from OXALATES and similar salts.
f. The gas burns with a rose-coloured flame. Cyanogen from CYANIDES,
FERRO-CYANIDES, &c.
g. The gas has an odour like that of rotten eggs, and blackens "lead-
paper." Sulphuretted hydrogen from SULPHIDES, &c.
h. Strong pungent odour, and turns reddened litmus paper blue*
A mmonia f rom ammoniacal salts and nitrogenous organic compounds.
G. A " sublimate " is deposited.
fa. Sublimes after fusion, substance very heavy. MEBCURIC CHLORIDE
is probable.
b. Sublimes without fusion ; substance heavy ; yellow while hot.
MERCUROUS CHLORIDE is probable.
c. Sublimes without fusion ; not heavy. AMMONIC CHLORIDE is
-J probable.
d. Sublimes without fusion ; substance rather heavy ; sublimate crys-
talline. ARSENIC ANHYDRIDE, Arsenolite, if altogether volatile, or
some METALLIC ARSENIDE, if mostly non-volatile.
e. Sublimes after fusion ; substance very light. Benzoic 'or some other
organic acid is probable.
( a. Fuses at first to a yellow liquid. OXIDE of ANTIMONY is probable,
b. Red or reddish-yellow while hot, yellow when cold. SULPHIDE of
ARSENIC is indicated. (Orpiment and Realgar among mineral sub-
J stances, as well as many sulpharsenides.)
c. Original substance red, and sublimate red when rubbed. Iodide of
Mercury is probable.
d. Sublimate easily melts to reddish-brown drops. SULPHUR or some
SULPHIDE is indicated.
CHAPTER II.— DETEEMINATIVE.
- g /-a. Turns red when rubbed. SULPHIDE of MERCURY is indicated, from
o -g £ ) CINNABAR and other mercuric minerals.
^ rt s ) k Remains black when rubbed. SULPHIDE of ANTIMONY, from ANTI-
M 02 V MONITE and other minerals containing antimony.
® °^ sq j a. Runs into drops when rubbed. MERCURY is shewn to be present.
b. Remains as an opaque crust. ARSENIC is probable, from many
2 JK 3 I minerals containing ARSENIC.
PQ^- 02 V
In cases where a sublimate or a gas is given off, some additional information,
or more precise results, may be obtained by making experiment 2. Whenever,
by the foregoing table, ammonia, arsenic, mercury, or antimony are thought to
be indicated, more distinct reactions may be obtained by mixing the assay
with a little " Black Flux," and heating in a fresh matrass.
TABLE II.— REACTIONS IN OPEN TUBE.
EXP. 2. — Heat a fresh portion of the substance under examination in a tube,
open at both ends, and held in an inclined position. (This experiment may be
omitted in all cases where no change was effected by the first experiment.)
A. A white sublimate is formed. This may be —
fa. OXIDE of ANTIMONY, from ANTIMONITE, &c.
| b. OXIDE of ARSENIC, from ARSENIDES. This sublimate will be in
brilliant crystals.
c. OXIDE of BISMUTH, from BISMITE, BISMUTHINITE, &c. This would
be yellow or reddish-brown while hot.
d. CHLORIDE of LEAD. This is readily fusible.
e. OXIDE of LEAD. Yellow while hot ; fusible at a red heat.
f. SULPHATE of LEAD, from Galena, &c.
g. CHLORIDES of MERCURY, from Salts of Mercury,
h. SELENITE of LEAD, from the very rare ISelenide.
i. OXIDE of MOLYBDENA, from minerals containing Molybdena. This
sublimate is in pale yellow shining crystals.
IJ. OXIDE of TELLURIUM, from the very rare metallic TELLURIDES.
§n f
(3 °
These are precisely as in the first experiment, with the addition of
5 3 I molybdic anhydride, which sublimes in pale yellow crystals.
^ «P3
Z*
t* I
B. Gases or vapours may be evolved —
a. SULPHUREOUS, from metallic Sulphides.
b. Resembling GARLIC (alliaceous), from compounds containing Arsenic.
c. Resembling DECAYING HORSE RADISH. From Selenides a red sub-
limate of Selenium is often deposited.
TABLE III.— REACTIONS ON CHARCOAL WITHOUT FLUXES.
EXP. 3. — Make a small cavity on the surface of a piece of charcoal, place a
portion of the substance to be examined in it, direct the tip of the flame of a
candle or oil-lamp upon it by means of the blowpipe, using first the " oxidizing
flame," afterwards the "reducing flame."
A. The substance melts, and is mostly absorbed by the charcoal without
depositing an "incrustation." Many alkaline salts behave thus, but few
minerals.
B. An incrustation is deposited on the charcoal, especially when the reducing
flame is used. Sometimes a small metallic bead will be produced from the assay
at the same time. Those most likely to be met with are the following :—
6 CHAPTER II.— DETEKMINATIVE.
a. White. Garlic odour. AESENIC is indicated. Ex. NATIVE AKSENIC,
SMALTITE, &c.
b. White. Little or no odour. Brittle metallic globules in RF.
ANTIMONY is indicated.
c. White. Yellow while hot ; malleable bead. Ex. TIN.
d. White. Yellow while hot ; no bead. Ex. ZlNC.
e. Yellow. Soft malleable bead. Ex. LEAD.
f. Yellow or orange. Soft brittle bead. Ex. BISMUTH.
g. Reddish-brown. Easily volatilized ; no bead. Ex. CADMIUM.
h. Dark red. Very bright white malleable bead. Ex. SILVER.
These reactions are often somewhat obscured by the presence of several
together.
C. A white, or nearly white, residue is left on the charcoal. This may,
perhaps, indicate Barium, Strontium, Lime, Magnesia, Alumina, Zinc, Silica.
Proceed to Exp. IV., Table IV.
D. A dark coloured residue is left. This indicates the presence of some
heavy metal. Proceed to Exps. as in Tables V., VI., VII.
E. The tip of the flame is seen to be tinged red, yellow, blue, green, &c.
Examine by Exp., Table VIII.
TABLE IV.— REACTIONS WITH COBALT SOLUTION.
EXP. 4. — "When a white residue is left from Exp. 3, either Baryta,
Strontia, Lime, Magnesia, Oxide of Zinc, Alumina, or Silica is probably
present. In such cases moisten with a drop of a solution of Nitrate of Cobalt
(Co), and heat strongly again.
A. If it appears intensely luminous, Strontium, Lime, Magnesia, or Oxide of
Zinc are probably present.
B. If as it cools, it turns —
a. Blue. ALUMINA is present ; SILICA, if only pale blue.
b. Green. ZINC is present.
c. Pink or red. MAGNESIA is present.
TABLE V.— REACTIONS ON CHARCOAL WITH FLUXES.
EXP. 5. — When a dark coloured residue is left from Exp. 3, mix a little dry
carbonate of soda with the assay and heat in the "Reducing Flame" (RF).
See p. 18, Part II.
a. Yellow malleable bead = GOLD.
b. Red malleable bead = COPPER.
c. White malleable bead, dull as it cools, white incrustation = TIN.
d. White malleable bead, very bright, dark red incrustation = SILVER.
e. Grey malleable bead, yellow incrustation = LEAD.
f. Grey brittle bead, yellow incrustation = BISMUTH.
g. White brittle bead, white incrustation = ANTIMONY.
h. White incrustation, easily volatilized, with garlic odour, no bead =
ARSENIC.
i. White incrustation, no odour, no bead, green when treated with Co
= ZINC.
j. Reddish-brown incrustation, no bead = CADMIUM.
TABLE VI.— REACTIONS WITH BORAX BEAD.
EXP. 6. — Make a "borax bead" and examine a portion of the assay (after
roasting if any sublimate was yielded by EXPS. 1 and 2), as in EXP. 6, p. 18,
Part II. (Substances printed in italics are very rare.)
A.— Oxidising Flame.
A. — COLOURLESS BEADS.
( Silica, Alumina, Binoxide of Tin, Baryta, \ when highly saturated ;
UOT I Strontia, Lime, Magnesia, Oxide of Silver, Vopaque (white) by flam-
AND -I ^ucina- Tellurous A nhydride. ) ing.
COLD ' Titanic Anhydride, Tungstic Anhydride, \
I Molybdic Anhydride, Oxides of Zinc, Cad- )»when feebly saturated.
Lead, Bismuth and Antimony.
CHAPTER II.— DETEEMINATIYE.
b. — YELLOW BEADS.
' Titanic Anhydride, Tungstio Anhydride, 1^ MgUy »att™ted ;
Oxides of Zinced Cadmium. fluTyb/flating? '
Oxides of Lead, Bismuth, and Anti- ) when highly saturated ;
TT J mony. j on cooling colourless.
j Sesquioxides of Cerium, Iron, and ) when feebly saturated;
Uranium. ) on cooling colourless.
Sesquioxide of Chromium ; when fully saturated ; when cold,
I yellowish-green.
L Vanadic Anhydride-, when cold, pale green.
c.— RED TO BROWN BEADS.
f Sesquioxide of Cerium ; on cooling yellow, enamel-like by flaming.
I Sesquioxide of Iron ; on cooling yellow.
Sesquioxide of Uranium ; on cooling yellow, enamel-yellow by
HOT. •{ flaming.
Sesquioxide of Chromium ; on coolieg yellowish-green.
I Sesquioxide of Iron, containing Manganese ; on cooling yellowish-
^red.
Oxide of Nickel (reddish -brown to brown); violet while hot.
COLD. ^ Sesquioxide of Manganese (violet-red); violet while hot.
Oxide of Nickel, containing Cobalt ; violet while hot.
d.— VIOLET BEADS (AMETHYST-COLOURED).
>wn to brov
violet -red.
)wnish.
( Oxide of Nickel ; on cooling reddish-brown to brown.
HOT. s Sesquioxide of Manganese ; on cooling violet-red.
V. Oxide of Nickel, containing Cobalt ; on cooling brownis
e.— BLUE BEADS.
HOT. -{ Oxide of Cobalt ; retains its colour on cooling.
COLD i Oxide of Copper (when highly saturated greenish-blue); green
' \ while hot.
f. — GREEN BEADS.
( Oxide of Copper; when cold, blue or greenish -blue.
""I on cooling the colour
Sesquioxide of Iron, containing Cobalt or changes, according to
HOT. \ Copper. I the proportion in which
Oxide of Copper, containing Iron or (the various oxides are
I Nickel. present, to light-green
L j blue, or yellow.
( Sesquioxide of Chromium, yellowish-green ; yellow to red while
COLD. < hot.
(, Vanadic A nhydride, greenish ; yellow while hot.
B. — Reducing Flame,
a.— COLOURLESS BEADS.
f Silica, Alumina, Binoxide of Tin.
Sesquioxide of Manganese ; sometimes, on cooling, pale rose
COLD « coloured'
Oxides of Silver, Zinc, Cadmium, Lead, ") with strong blowing;
I Bismuth, Antimony, Nickel, Tellurous An- With feeble blowing
{hydride. ) grey.
TT ( Oxide of Copper ; when highly saturated ; on cooling opaque and
I red.
CHAPTER II.— DETERMINATIVE.
b. — YELLOW TO BROWN BEADS.
f Titanic Anhydride (yellow to brown); when highly saturated
1 enamel-blue by flaming.
HOT. -I Tungstic Anhydride (yellow to dark yellow); when cold brownish.
I Molybdic Anhydride (brown to opaque).
t. Vanadic Anhydride (brownish); green when cold.
c.— BLUE BEADS.
HOT. -{ Oxide of Cobalt ; retains its colour on cooling.
d.— GREEN BEADS.
HOT C Sesquioxide of Iron (yellowish-green); especially when cold.
Sesquioxide of Uranium (yellowish-green); when highly saturated
black by naming.
Sesquioxide of Chromium (light to dark emerald-green).
HOT. -{ Vanadic Anhydride ; brownish while hot.
e. — GREY AND CLOUDY BEADS.
^
colourless.
COLD, f <**f o^^er,Z^C Cadmium, Lead,)
| Bismuth, Antimony, Nickel. /co
f.— RED AND OPAQUE BEADS.
COLD. -{ Oxide of Copper, when highly saturated ; colourless while hot.
TABLE VII.— REACTIONS WITH MICROCOSMIC SALT.
Substances printed in italics are very rare.
A.— Oxidising Flame,
a. — COLOURLESS BEADS.
( Silica ; soluble only in minute quantity.
! Alumina, Binoxide of Tin ; soluble with difficulty.
1 when highly saturated
Baryta, Strontia, Lime, Magnesia. >become opaque by flam-
J ing.
Tungsten, Antimony ; Oxides of Zinc, \ if not too highly satu-
Cadmium, Lead, Bismuth, Titanium. f rated.
b.— YELLOW BEADS.
Anhydrides of Tungsten^ Antimony,
of Zin<
TT J Oxide of Silver, yellowish ; when cold opalescent.
] Sesquioxide of Iron. ) when feebly saturated ;
,, Cerium. j on cooling colourless.
„ Uranium ; when cold yellowish-green.
Vanadic Anhydride, deep yellow ; when cold of a lighter shade.
COLD, -( Oxide of Nickel; while hot reddish.
c. — RED BEADS.
) when highly saturated ;
Ti-.,™ J ,, Cerium. J when cold yellow.
LOT. <^ ^.^ ^^.^ _.„,... when cold yellow.
reddish ; when cold emerald-green.
CHAPTER II.— DETERMINATIVE. 9
d.— VIOLET BEADS.
HOT. -{ Oxide of Manganese, brownish -violet ; on cooling pale reddish- violet,
e. — BLUE BEADS.
HOT. -{ Oxide of Cobalt ; when cold of the same colour.
COLD. -{ Oxide of Copper ; green while hot.
f.— GREEN BEADS.
f ^ on cooling the colour
Sesquioxide of Iron, containing Cobalt or changes, according to
Copper. I the proportion in which
Oxide of Copper, containing Iron or (the various oxides are
HOT. -{ Nickel. | present, to light green,
J blue, or yellow.
Oxide of Copper ; when cold blue or greenish-blue.
1 Molybdic Anhydride, yellowish-green ; when cold of a lighter
t shade.
COLD I Sesquioxide of Uranium, yellowish-green ; while hot yellow.
' t Sesquioxide of Chromium, emerald-green ; while hot reddish.
B. — Reducing- Flame.
a. — COLOUELESS BEADS.
C Silica ; but slightly soluble.
Alumina, Binoxide of Tin ; soluble with difficulty.
'J when highly saturated
J Baryta, Strontia, Lime, Magnesia. Vbecome opaque by flam-
j ing.
Oxides of Manganese, Cerium.
COLD. | Oxides of Silver, Zinc, Cadmium, Lead,^
I Bismuth.
Antimonious anhydride. > with continued blowing.
Oxide of Nickel, if the exp. be made on
I Charcoal. J
b. — YELLOW TO RED BEADS.
C Sesquioxide of Iron ; on cooling greenish, then reddish.
Titanic Anhydride, yellow ; on cooling violet.
HOT. s Vanadic Anhydride, brownish; when cold emerald-green.
Titanic Anhydride, containing Iron. ) yellow ; when cold
L Tungstic Anhydride, „ „ J blood-red.
c. — VIOLET BEADS.
COLD. •{ Titanic Anhydride ; yellow while hot.
d. — BLUE BEADS.
p f Oxide of Cobalt ; of the same colour when hot.
yOLD. ^ Tungstic Anhydride ; while hot brownish.
e.— GREEN BEADS.
Sesquioxide of Uranium ; while hot less bright.
Molybdic Anhydride ; while hot of a dirty green colour.
Vanadic Anhydride ; while hot brownish. _
Sesquioxide of Chromium ; while hot reddish
f. — GREY AND CLOUDY BEADS.
{~ -, . T •, 1 takes place quickest on
Oxides of Silver, Zinc Cadmium, Lead, I Ch ^ « continued
Bismuth, Antimony, Nickel. /blowing colourless.
g.— KED AND OPAQUE BEADS.
COLD. •{ Oxide of Copper, when highly saturated, or with Tin on Charcoal.
B
10 CHAPIER II.— DETERMINATIVE.
TABLE VIII. —FLAME COLOURATIONS.
BX.P. 8. — A fragment of the substance under examination is held by
platinum-pointed forceps, and the tip of the oxidising flame is directed on it— a
piece of platinum wire with a little of the powder sticking to it will usually
•uffice. (Note — Substances containing easily reduceable metals, as tin or lead,
or substances which yield sublimates by Exp. 1, should not be thus treated, as
the platinum forceps would be spoiled. The experiment may, however, be made
by using charcoal, or a fragment of narrow glass tube, &c., as the support.)
A. The flame is tinged strongly yellow.
Sodium in some form is indicated.
B. Blue.
a. Chloride of Copper (ATACAMITE) colours the flame at first intensely
blue, afterwards greenish.
b. Bromide of Copper. This is very rare.
c. Arsenic. This is a pale blue.
d. Antimony. This gives a pale greenish-blue.
e. Lead. Bright blue.
f. Selenium. Intense blue.
These substances are easily distinguished from each other by Exps.
1, 2, 3.
0. Green.
a. Baryta and its compounds. Yellowish -green.
b. Molybdenum and its compounds. Yellowish-green,
c. Copper and its compounds, except the chloride.
d. Telluric anhydride. This is very rare.
e. Phosphorus and compounds. Pale bluish-green.
f. Boric Acid or Anhydride.
D. Red.
a. Lithia. Very intense crimson,
b. Strontia. Crimson.
c. Lime. Brick red.
E. Violet.
Potash, This tint is often overpowered by the presence of the yellow
flame of soda, but it may always be detected by looking through a
piece of deep blue glass, which completely absorbs the yellow-
without interfering with the violet rays.
Many of the above flame colourations are well brought out by the appli-
cation of a drop of hydrochloric acid, applied to the powder before heating.
For phosphorus and phosphates sulphuric acid affords the most delicate
reactions.
TABLE IX.— REACTIONS WITH SOLVENTS.
A. Water.
Very few minerals are soluble in water. Those that occur in Cornwall and
Devon are : —
Melanterite, Johannite, Goslarite,
Cyanosite, Kalinite, Halite.
A large number of artificial products are soluble in water, including nearly all
nitrates, acetates, and oxalates, chlorides (except those of lead, mercury, and
silver), many sulphates, the carbonates and oxides of the alkalies, &c.
B. Hydrochloric acid, dilute or concentrated, gently warmed if necessary,
a. With effervescence.
CHAPTER II.— DETEEMINATIYE. 11
1. The gas evolved has little or no smell, and if conducted into
"lime water" yields a white precipitate. The carbonates of
lime, magnesia, manganese, iron, and most other carbonates
behave thus.
2. The gas evolved has a strong sulphureous odour. Many sulphite*
and hypo-sulphites behave thus.
3. Odour resembling that of rotten eggs. Many sulphides,
b. Without effervescence.
Silicates containing only a small proportion of silica, silicates of the
alkalies, &c. These usually leave a gelatinous or slimy deposit of
silica undissolved.
C. Nitric Acid ; dilute or concentrated ; warmed if necessary.
Substances having a metallic lustre should be treated with nitric acid,
when they will often be dissolved or decomposed; red nitrous
fumes being at the same time given off from the acid.
D. Aqua Regia, concentrated and warmed, in cases where nitric acid and
hydrochloric acid have both failed.
Gold, Platinum, and many other substances, which are scarcely, or not
at all, acted upon by HC1 or HNO3, are readily decomposed by
Aqua Regia.
E. Special solvents.
a. Sulphuric Acid. Not often necessary, but useful for some few
minerals.
b. Ammonia. Chloride of Silver and Chloride of Copper are readily
soluble in ammonia.
c. Caustic Potash. Opal and some other minerals are partially or
completely dissolved in Potash.
d. Hydrofluoric Acid. Useful for the solution of silica and all silicates.
The substance having been brought into solution will be in a fit state for
examination according to the methods described in all works on qualitative
analysis. Valuable information may, however, be often obtained from the
colour of the solution. Thus, if it be
BLUE, Copper is probably present.
GKEEN, Nickel, Iron, or Manganese.
PINK, Cobalt or Manganese.
YELLOW or BROWN, Gold, Iron, Platinum, or Chromium.
A good deal of information may also be gained by observing the colour,
appearance, &c., of the substance when powdered. Thus if it be —
A. BLACK, and comparatively heavy, one or more of the oxides of Manga-
nese, Copper, Iron, Nickel, or Cobalt ; or of the sulphides of Mercury, Silver,
Copper, Bismuth, Lead, Antimony, Iron, Cobalt, Nickel, &c., may be present.
B. BLACK, and very light, Carbon in some form.
C. BROWN, Peroxide of Iron, or Sulphide of Tin, &c.
D. RED, some oxides of Mercury, Lead, Iron, Copper, &c.; Sulphides of
Mercury or Arsenic ; Iodide of Mercury ; Chromate of Potash, Ferridcyanide of
Iron, Perchloride of Platinum, &c. , may be present.
E. YELLOW, Chromates of Potassium, Sodium, Ammonium, Barium, Stron-
tium, Calcium, Bismuth, Lead, &c.; Sulphides of Cadmium, Arsenic, Tin, &c.;
Oxides of Lead, Tin, Bismuth ; Ferrocyanide of Potassium ; Iodide of Lead, &c.
F. GREEN, Oxide of Mercury ; many salts of Iron, Copper, Nickel, Chro-
mium ; Manganates of Potash and Soda, &c.
G. BLUE, Salts of Copper ; anhydrous Salts of Cobalt, Phosphate of Iron,
Prussian Blue, Ultramarine, &c.
H. WHITE or COLOURLESS. Absence of either of the above in any con-
siderable quantity; probable presence of silica or silicates, or most salts or
oxides of the alkalies or alkaline earths, or of Zinc ; Chlorides of Mercury,
Silver, Lead ; Carbonates of Lead, Bismuth ; very many organic substances, &c.
The foregoing tables, I. to IX., form a suitable method for the "preliminary
examination " of all substances, previous to their detailed analysis, whether
natural or artificial, inorganic or organic.
12
CHAPTER II.— DETERMINATIVE.
It is seldom, however, that the nature of a substance is altogether unknown,
and with the limited number of minerals in the district under consideration, a
great deal of time may often be saved by using the following scheme, in which
the minerals are grouped solely in accordance with their most evident characters,
and those the least likely to be misunderstood.
Sometimes a mineral appears in two or more groups, so as to afford a greater
chance of its recognition ; nevertheless, to ensure success, the characters
of a specimen should be compared with those of the groups in their order.
TABLE X.— MINERALS OF CORNWALL AND DEVON, ARRANGED IN
GROUPS FOR CONVENIENCE OF IDENTIFICATION.
GKOUP I.— PULVERULENT.
(Occurring in soft earthy masses, or as a powdery coating on other minerals.)
Name.
Colour.
Behaviour on Charcoal
B. B.
In Borax Bead.
Remarks.
Black Sulpliuret
Black.
Easily reduced to a
_
Very rare indeed.
of Silver.
bright white bead of
See Argentite,
silver.
p. 9.
Condurrite,
Do.
Easily reduced to a bead
Green OF, red
Very rare & local.
of copper, with strong
& opaque RF.
See Domeykite,
alliaceous odour.
p. 42.
Melaconite.
Do.
Easily reduced to a bead
Do.
Not uncommon in
of copper, without alli-
copper mines.
aceous odour.
Asbolane.
Do.
Infusible.
Blue, both OF
Very rare & local.
and RF.
Wad.
Do.
Do.
Amethystine
Local, but not
OF, colourless
RF.
very rare.
Pyrolusite.
Do.
Do.
Do.
Anhydrous, only
the outer coating
pulverulent.
Red Ochre.
Red.
Do.
Reddish-yellow
Common in some
OF, bottle-
distsrict. See
green RF.
Hematite, p. 55.
Umber.
Brown.
Do.
Do.
Do. See Limonite.
p. 63.
Yellow Ochre.
Yellow.
Do.
Do.
Do. do.
Blue Iron Earth
Blue.
Fusible to a magnetic
Do.
Local & rare. See
mass.
Vivianite, p. 104.
Pitticite.
Yellow to
Do.
Do.
Rather rare and
brown.
very local.
Plumbic Ochre.
Yellow.
Easily reduced to a bead
—
Very rare.
of lead.
Bismite.
Do.
Easily reduced to a bead
—
Very rare.
of bismuth.
Cervantite.
Do.
Easily reduced to a brit-
—
Not uncommon ;
tle bead of antimony.
but local.
Wolframite.
Do.
Infusible and not re-
Occurs as a coat-
ducible.
ing on Wolfram.
Local and rare.
Zippseite.
Yellow or
Do.
Green bead OF
Local and rare.
grnsh-yel.
and RF.
Langite.
Blue or Easily reduced to a bead
Green OF, red
Local and rather
greenish.
of copper.
& opaque RF.
rare.
Annabergite.
Green.
Fusible, with strong al-
—
Local and very
liaceous odour.
rare.
Chlorite.
Dark green Generally fusible to a
Reddish-yellow
Compact, massive
or blue.
magnetic mass.
OF, bottle-
very common.
green RF.
(Peach.)
Kaolin.
White.
Infusible; blue with Co.
Local ; very com-
mon.
Magnesite.
Do.
Infusible ; pink with Co.
Very doubtful as
! Sol. eff. with
a Cornish or De-
von species.
Meeolite.
Do. j Fusible to a white ena-
Very rare and
mel ; blue with Co.
local.
CHAPTER II.— DETERMINATIVE.
13
GROUP II.— FOLIACEOUS.
(Occurring in thin leaves or scales ; or may be easily split up into such with
a penknife.)
Name.
Colour.
Behaviour on Charcoal
B. B.
n Borax Bead.
Remarks.
Gilbertite.
White or
Infusible; blue with
_
Local; chiefly in
yellowish
Co.
china clay dis-
tricts.
Talc.
VVhite or
Infusible ; pink with
Local ; with ser-
Gypsum.
greenish.
White, yel-
Co.
Infusible ; fusible to a
pentine.
Local and rare ;
lowish, or
brownish
clear bead with Fluor
Spar.
more often crys-
tals with very
easy cleav. than
in thin plates.
Goethite.
Yellow or
Infusible; hydrous.
Reddish-yellow
More often in dark
brown.
OF, bottle-
coloured crys-
green RF.
tals.
Hematite.
Red,brown
Infusible ; anhydrous.
Do.
Do.
black.
Brookite.
Brown.
Do.
Yel. hot, violet
cold RF.
Exceedingly local
and rare.
Molybdenite.
Lead grey.
Infusible ; anhydrous ;
—
Rare and local.
turns flame greenish.
Graphite.
Do.
Infusible ; anhydrous.
Do.
Marmolite.
Green.
Infusible ; pink with
—
Local ; with com-
Co.
mon serpentine.
Muscovite.
Brown.
Difficulty fusible (about
—
Often occurs in
4); blue with Co.
granite.
cSchiller Spar.
Yellow to
Difficulty fusible.
—
Occurs imbedded
brown.
in serpentine.
Chlorite.
Green.
Difficulty fusible to a
Reddish-yellow
Very local in the
magnetic mass.
OF, bottle-
foliated condi-
green RF.
tion.
Lepidolite.
White or
Fusible ; tinges flame
The white mica in
peach.
red if moistened with
H2S04.
granite is chiefly
Lepidolite.
Lepidomelane.
Brown or
Fusible to a magnetic
Reddish-yellow
The dark mica in
black.
mass.
OF, bottle-
granite is chiefly
green RF.
Lepidomelane.
Covellite.
Dark blue.
Fusible ; easily reduced
Green OF, red
Very rare.
to a bead of copper.
and opaque
RF.
Chalcophyllite.
Green.
Do.
Do.
Rare and local.
Torbernite.
Do.
Fusible ; reduced with
Do.
Do.
difficulty to a bead of
copper on addition of
soda.
Autunite.
Yellow.
Fusible.
Very rare & local.
Vivianite.
Green, blue
Fusible to a magnetic
Reddish-yellow
Rare and local.
or brown.
mass.
OF, bottle-
green RF.
Erythrite.
Pink.
Fusible ; strong allia-
Blue, both OF
Very rare & local.
ceous odour.
and RF.
Copper.
Red.
Fusible; malleable.
Occasionally
found in thin
leaves in the
joints of serpen-
tine and other
rocks.
Gold.
Yellow.
Fusible ; malleable.
—
Very rare ; in
stream works.
14
CHAPTER II.— DETEEMINATIVE.
GROUP III. -CAPILLARY.
(Occurring in soft or flexible fibres.)
Name.
Colour.
Behaviour on Char
coal B. B.
' In Borax Bead
Solubility.
Remarks.
Araenolite.
White.
Readily fusible
Slightly
Very rare.
strong arsenica
sol. in
odour, and white
water.
coating.
Goslarite.
Do.
Readily fusible at
—
Soluble in
Do.
first, then infusi-
water.
ble ; green with
Co.
Kalinite.
Do.
Readily fusible at
—
Soluble in
Rare & local.
first, then infusi-
water.
ble ; blue with Co.
Mesolite.
Do.
Fusible to a white
Soluble in
A doubtful
enamel; blue with
HC1.
species.
Co.
Natrolite.
Do.
Fusible ; blue with
—
Slowly sol.
Extremely
Co.
in HC1. rare.
Tavistockite.
Do.
Do.
.—
Do.
Do.
Asbestos.
Do.
Do.
Insol. in
Local, rather
acids.
rare.
Actinolite.
Green.
Fusible.
—
Do.
Local.
Silver.
White, of-
ten tar-
Malleable, fusible
to a bead of Silver
-
Soluble in
HN03.
Very rare.
nished.
Cerussite.
Do.
Fusible ; easily re-
—
Sol. eff.
Local, not rare
duced to Lead.
HC1.
Melanterite.
Pale green.
Fusible at first,
then infusible.
Reddish -yel-
low OF, bot-
Soluble in
water.
Local, rather
rare, a pro-
tle green
duct of de-
Aragonite.
White to
red or
Infusible, alkaline
after heating.
RF.
Sol. eff. in
HC1.
composition.
Very rare and
local.
Gypsum.
White to
Infusible ; fusible
Insol. in
Rare.
brown.
with Fluor Spar to
acids.
a white bead.
Chrysotile.
White to
Infusible ; pink
—
—
Occurs with
grey,
with Co.
serpentine in
narrow veins
Prehnite.
Pale green.
Fusible ; blue with
—
Insol. in
Very rare.
Co.
acids.
Annabergite.
Green.
Fusible ; arsenical
Green,sol.
Do.
odours.
inHN03.
Atacamite.
Do.
Fusible ; bright
Green OF,
Soluble in
Do.
blue flame ; bead
red and
ammonia.
of Cu.
opaque RF.
Olivenite.
Greenish-
Fusible, strong ar-
Do.
Sol. HC1.
Rather rare
grey.
senical odour ;
now.
green flame.
Connellite.
Blue.
Fusible, blue flame;
Do.
HN03.
Very rare.
bead of Cu.
Pyromorphite
Green.
Fusible ; crystal-
Do.
Not uncom.
lizes on cooling ;
in lead mines
with soda a bead
in small hex-
of lead.
ag. prisms,
rarely acicu-
lar.
Mimetite.
Yellow to
Fusible ; strong ar-
—
Do.
Do.
brown.
senical odour ;
bead of lead.
Cervantite.
Yellow.
?usible ; much
Sol. HC1.
Local, but not
white fume.
very rare.
CHAPTER II.— DETEKMINATIVE.
15
GROUP III.— CAPILLARY (Continued).
Name.
Colour.
Behaviour on Char- T_ •[>„_„_ T> j
coal B. B. In Borax Bead
Solubility
Remarks.
Erythrite.
Pink.
Fusible ; strong Blue, both
HN03.
Rare.
arsenical odours. flames.
Chalcotrichite
Red.
Easily reduced to Green OF,
Do.
Rare & local
a bead of copper.
dark red
in this form.
and opaque
See Cuprite,
RF.
p. 39.
Millerite.
Yellow and
Fusible ; sulphure-
Do.
Rare.
metallic.
ous odour, brittle
bead.
Bismuthinite.
Yellow or
Fusible ; sulphure-
Do.
Do.
grey, and
ous odour : bead
metallic.
of Bismuth.
Antimonite.
Grey and
Fusible ; much
HC1.
Local, not rare
metallic.
white fume.
Jamesonite.
Do.
Fusible ; much
Sol.
in
Do.
white fume, and
bead of lead.
part.
Wittichenite.
Grey.
Fusible ; bead of
Green OF,
HN03.
A doubtful
copper.
dark red
species.
RF.
Vivianite.
Green to
Fusible to a mag-
Reddish -yel-
Do.
Rare.
brown.
netic mass.
low OF, bot-
tle green
RF.
Tourmaline.
Very dark
Do.
Do.
Insol.
Very common
green,
but not usu-
brown, or
ally acicular.
black.
Manganite.
Greyish-
Infusible.
Amethystine
HC1.
Rare.
black, me-
OF, colour-
tallic.
less RF.
Pyrolusite.
Do.
Do.
Do.
Do.
Local but com-
mon, usually
acicular.
Sulphur.
Yellow.
Combustible, blue
Insol.
Very rare in
flame.
Corn. orDev.
GROUP IV.— SAPID.
(Soluble in water, and consequently having a distinct taste.)
Name.
Colour.
Taste. Special Experiments.
Remarks.
Halite.
White or
Taste of com- Precipitates Mtrate of
A doubtful Corn-
brownish
mon salt. Silver.
ish or Devon
species.
Goslarite.
White.
Nauseous, me- With Co. green.
Very rare.
tallic.
Arsenolite.
Do.
Sweetish. Alliaceous odour on
Very rare ; en-
charcoal.
tirely volatile.
Kalinite.
Do.
Sweetish, as- Blue with Co.
Very rare.
tringent.
Melanterite.
Pale green.
Nauseous, like With borax, iron reac-
Local, but not un-
ink. tions.
common.
Cyanosite.
Johannite.
Blue or
greenish.
Green.
Very nauseous, On charcoal a bead of
metallic. Copper.
Bitter, astrin- With borax, Uranium
Not uncommon in
copper mines.
Very rare.
16
CHAPTER II.— DETEEMINATIYE.
GROUP V.— MALLEABLE.
(May be beaten out into thin plates without breaking under the hammer.)
Name.
Colour.
Special Experiments.
Remarks.
Gold.
Yellow.
Insoluble in HC1 or HN03 ;
Very rare.
yellow solution in Aqua
Regia.
Silver.
White, often
Soluble in HN03 ; precipi-
Rare.
tarnished.
tated by HC1 as a white
curd, which is sol. in am.
Copper.
Argentite.
Red.
Lead-grey.
Green solution in H]ST03.
On charcoal a bead of
Common.
Rare ; only imperfectly
Silver.
malleable.
Chalcocite.
Do.
On charcoal a bead of
Common ; only imperfectly
Copper.
malleable.
Bismuth.
Reddish-white.
Fusible on charcoal, a red-
Rather rare ; only imper-
Molybdenite.
Lead-grey.
dish-yellow coating.
Infusible, tinges flame
fectly malleable.
Flexible, usually folia-
green.
ceous ; rare.
Kerargyrite.
Greyish.
Fusible, yields a bead of
Rare.
silver ; sol. in ammonia.
GKOUP VI.— PLASTIC.
(May be moulded by the fingers, at least when wet.)
Name.
Colour.
Special Experiments.
Remarks.
Kaolin.
Chloropal.
Glauconite.
Smectite.
Saponite.
White.
Yellowish-green
Green.
Brownish.
Greyish or yell.
Infusible ; blue with Co.
Infusible ; turns black and
magnetic.
Fusible to a dark magnetic
glass.
Infusible, or fusible to a
dark magnetic glass.
Difficultly fusible.
Very common.
Not uncommon ; associated
with china clay.
A doubtful Cornish or
Devon species.
Falls to powder if placed
in water ; a very doubt-
ful species.
See Steatite, p. 86.
GROUP VII.— BOTH COLOUR AND STREAK BLUE.
Name.
Behaviour on Charcoal.
Solubility.
Remarks.
Chessylite.
Readily yields a bead of
copper.
Soluble withe/.
in HC1.
Not uncommon in small
quantities in cop. mines.
Clinoclase.
Strong alliaceous odours,
and yields a bead of cop-
Soluble, except
the arsenic, in
Rare ; may be best known
by the form of its crys-
per, more readily on addi-
HN03.
tals.
tion of soda.
Liroconite.
Do.
Do.
Do.
Connellite.
Yields a bead of copper ;
strong sulphureous odour ;
Not readily so-
luble in acids.
Exceedingly rare ; only a
few specimens known.
bright blue flame.
Langite.
Yields a bead of copper,
Do.
Rare ; occurs as a powdery
with sulphureous odour.
coating, or crystalline, on
killas of copper lodes.
CHAPTER II.— DETEEMINATIVE.
17
GROUP VII (Continued).
Name.
Behaviour on Charcoal.
Solubility.
Remarks.
Demidoffite.
Infusible ; with soda yields
Slowly decom- Extremely rare.
a bead of copper.
posed by HC1
leaving gela-
tinous silica.
Linarite.
Fusible ; yields a small
Insoluble in
Extremely rare ; the streak
grain of copper, and depo-
acids.
is very pale blue.
sits a yellow coating of
oxide of lead.
Chlorite.
Fusible to a magnetic bead.
Do.
Usually earthy or folia-
ceous, and often more
or less green.
Blue Iron Earth.
Do.
Soluble in HC1.
Pulverulent; rare.
GROUP VIII.— BOTH COLOUR AND STREAK GREEN.
Name.
Behaviour on Charcoal.
Solubility.
Remarks.
Atacamite.
Easily reduced to a bead
Soluble in ammo-
Very rare and local.
of copper ; colours flame
nia, colouring it
strongly blue.
strongly blue.
Brochantite.
Easily reduced to copper ;
Soluble in HC1.
Rare and local.
sulphureous odour.
Malachite.
Reduced to copper with-
Soluble with effer-
Common in cop. mines ;
Chrysocolla.
out fluxes.
Reduced to copper only
by addition of fluxes.
vescence in HC1.
Slowly decomposed
by HC1, leaving
gelatinous silica.
streak very pale green.
Rare in copper mines ;
not uncommon in the
Lizard district ; streak
very pale green.
Olivenite.
Fuses readily, sometimes
deflagrates ; gives off al-
Soluble, except ar-
senic anhydride,
Local, but not very rare.
liaceous fumes, and de-
in HJSTO3 ; soluble
posits an abundant
in HC1, forming a
white incrustation on
green solution.
the cool part of the sup-
port ; with soda yields
a bead of copper.
Chalcophyllite.
Do.
Do.
Rare ; best known by the
form of its crystals.
Clinoclase.
Do.
Do.
Rare and local ; best dis-
tinguished from Oli-
venite by the form of
its crystals ; more of-
ten blue than green.
Liroconite.
Do.
Do.
Rare ; only green occa-
sionally ; best distin-
guished by the form of
its crystals.
Cornwallite.
Do.
Do.
Very rare ; never in
crystals.
Erinite.
Do.
Do. '
Very rare ; occurs in
mammillated crusts.
Bayldonite.
Fuses readily, gives off al-
Soluble in warm
Very rare ; occurs in
liaceous odours, and de-
HN03, but not
minute mammillary
posits a yellow coating
near the assay ; leaves a
readily ; the solu-
tion yields a white
concretions ; grass-
green to blackish-
hard white alloy of cop-
per and lead.
ppt. of PbS04 on
addition of sul-
greeo.
phuric acid.
18
CHAPTER II.— DETERMINATIVE.
GROUP VIII. (Continued.)
Name.
Behaviour on Charcoal.
Solubility.
Remarks.
Chenevixite.
Fuses readily to a black Readily soluble in
Very rare ; occurs in
magnetic scoria; gives
HNO3 or HC1,
small compact masses,
off arsenical fumes ; with
fluxes yields a grain of
forming a green
solution.
imbedded in quartz.
copper.
Libethenite.
Fuses to a dark bead of
Readily soluble in
Rare and local.
metallic appearance ; in
HNOg, soluble
RF with soda yields a
also in HC1 or am-
bead of copper, but not
monia ; decom-
readily.
posed by KHO.
Lunnite.
Do.
Do.
Only one British speci-
men known.
Torbernite.
Fuses to a dark mass,
Soluble in HN03.
Local, but not rare, usu-
which crystallizes on
ally in very thin crys-
cooling ; with soda
talline plates.
yields a bead of copper.
Pyromorphite.
Fuses readily, crystallizes
Soluble in HNOS,
Not uncommon in lead
on cooling ; with soda
the solution yields
mines; usually occurs
yields a bead of lead, and
a white ppt. on
in minute hexagonal
coats the support yel.
addition of H2
prisms of a green
S04.
colour ; streak often
uncoloured.
Pharmacosi-
Fuses readily to a black
Soluble in HN03
Rare and local ; usually
derite.
magnetic mass, giving
orHCL
occurs in minute green-
off arsenical odours ;
ish cubes, variously
with borax yields iron
modified.
reactions.
Scorodite.
Do.
Do.
Very rare and local ;
usually occurs in slen-
der prisms of a pale
bluish-green colour ;
streak nearly colorless.
Vivianite.
Fuses readily to a dark
Do.
Local, but sometimes
magnetic mass, which
not uncommon ; very
yields iron reactions
variable in colour, but
with borax.
powder always blue
after a little exposure.
Cronstedtite.
Fuses to a magnetic mass ;
with borax yields iron
Slowly decomposed
by HC1, leaving
Very rare and local.
reactions.
gelatinous silica.
Annabergite.
Fuses readily, giving off Soluble in HC1 or
Local and rare.
strong alliaceous odours
HNOq, forming a
with borax yields nickel : clear green solu-
reactions. tion.
Chlorite.
Fusible to a magnetic bead Insoluble in acids.
Com., but usually earthy.
GROUP IX.— COLOUR AND STREAK KED, YELLOW, OR BROWN.
Name.
Hard-
ness.
Streak.
Behaviour on Char-
coal.
Solubility.
Remarks.
Cervantite.
Bleinierite.
Soft.
2-0-4-0
Yellow.
Do.
Volatile OF; re-
duced to a bead of
antimony RF.
Fuses readily to a
grey brittle glo-
bule with sulphu-
reous odour.
Sol. in HC1,
sometimes
re-precip. on
addition of
water.
Sol. in strong
HC1, giving
offH2S,
Local, but not
very rare.
Do.
CHAPTER II.— DETEKMINATIVE.
19
GROUP IX. (Continued.)
Name.
Hard-
ness.
Streak.
Behaviour on Char-
coal.
Solubility.
Remarks.
Pharmacosi-
2-5
Pale brown
Fuses readily to a
Sol. in HC1
Rare & local,
derite.
to green.
dark magnetic
mass, giving off al
or HN03.
usually in
small green-
liaceous odours
ish cubes.
with borax yields
iron reactions.
Pitticite.
2-3
Yellow or
Do.
Sol. in HC1.
Local, but
brownish.
sometimes
not very rare
A product of
the decomp.
of other mi-
nerals in old
works; never
crystallized.
Goethite.
5-5-5
Do.
Infusible ; with
Slowly sol. in
Loc., but not
borax yields iron
HC1.
rare ; occurs
reactions.
usually in
dark brown
bril. crystls.
Limonite.
Do.
Yellow or
brown.
Do.
Do.
Very com.,
oft. radiated
but never in
crystals ;yel.
ochre is soft.
Anatase.
5-5-6
Pale brown.
Infusible ; with
Slowly sol. in
Very rare &
borax yields tita-
concentrat.
local.
nium reactions.
H2S04; in-
sol. in HC1
or HN03.
Rutile.
Do.
Do.
Do.
Do.
Do.
Brookite.
Do.
Do.
Do.
Do.
Do.
Titanite.
5-5-5
Greyish or
Very slightly fusi-
Decomposed
Do.
brownish.
ble.
by HC1.
Olivenite.
3
Pale brown
to green.
Fuses readily, and
gives off alliace-
ous odours ; with
Sol. in HC1,
& all except
arsenic an-
Local but not
very rare.
soda yields a bead
hydide in
of copper.
HN03.
Hisingerite.
3-5-4
Yellow to
Fuses to a dark
Soluble, ex-
Local & rare.
brown.
magnetic bead,
but not readily.
cept silica,
in HC1.
Pyromorphite.
Do.
Pale brown.
Fuses readily to a
Sol.inHN03,
Not uncom.
bead which crys-
precip. by
in lead mines
tallizes on cool-
H2S04.
cob?, usually
ing ; Avith soda
green, streak
yields a bead of
pale green.
lead.
Autunite.
1-2-5
Yellow.
Fuses readily to a
Sol.inHN03,
Local & very
dark mass with
forming a
rare; usually
crystalline surface
yellow solu-
as yellow
tion.
scales.
Blende.
3-5-4
Pale brown.
Infusible ; decrepi-
tates strongly ;
Very slowly
soluble in
Very com,,
and widely
support often
slightly coated
H2S04, giv-
ing oft' H2S.
diffused.
Avith Avhite.
Wolfram.
5-5-5
Dark brown.
Infusible, or diffi-
Slowly de-
Loc., but not
culty fusible ; de-
crepitates strong-
composed
byHCl, de-
rare; usually
imbedded in
ly.
positing yel.
quartz or
tungstic an-
chlorite.
hydride.
20
CHAPTER II.— DETEKMINATIVE.
GEOUP IX. (Continued.)
Name.
Hard-
ness.
Streak.
Behaviour on Char-
coal.
Solubility.
Remarks.
Retinite.
1-2-5
Pale brown.
Burns with a bright
flame.
Partly sol. in
alcohol or
In England
found only
ether ; insol.
at Bovey
in acids.
Tracey.
Cuprite.
3-5-4
Red or dark
brown.
Easily reduced to a
bead of copper.
Sol, in HN03,
forming a
Common.
green solu-
tion.
Hematite.
5-5-6-5
Do.
Infusible ; magne-
Slowly sol. in
Do.
tic ; with borax
HC1.
gives iron reac-
1 tions.
Erythrite.
1-5-2-5
Pink. Fusible readily ;
Sol. in HC1 or
Local & rare.
gives off alliace-
HN03.
ous odours ; with
borax yields co-
balt reactions.
Pyrargyrite.
2-2-5
Dark red.
Fuses readily to a
Decomp. by
Do.
dark bead ; after HNOg, pre
long roasting; cipitatedon
yields a bead of; addition of
silver.
HC1.
GROUP X. — COLOUR VARIOUS, STREAK BLACK OR VERY DARK, H. BELOW 5.
(Easily scratched with a knife.)
Name.
Colour.
Streak.
Sp. Gr.
Behaviour on
Charcoal.
Solubility.
Remarks.
Antimonite.
Lead-grey.
Black.
4-5-4-7
Readily fusible;
Soluble in
Common,
volatile ; sulphu-
wannHCl,
but local.
reous odour ;
gives off
white coating.
H2S.
Jamesonite.
Do.
Do.
5-5-5-8
Readily fusible ;
Soluble in
Common,
sulph. odour ;
HN08,pre-
but local.
yellow coating ;
cipitated
bead of lead.
by H2SO4.
Antimony.
Tin-white.
Grey and
6-6-6-8
Readily fusible &
Soluble in
A doubtful
shining.
volatile ; white
Aqua Reg.
British
coating.
species.
Arsenic.
Dark grey-
Do.
5-9-6-0
Readily fusible &
Soluble in
Do.
ish.
volatile; strong
HC1.
alliaceous odour.
Berthierite.
Grey or
brown.
Dark grey
or black.
4-4-3
Readily fusible to
a dark magnetic
Sol.inHCl,
giving off
Local, but
probably
slag ; white coat-
H2S.
not very
ing ; sulphureous
rare.
odour.
Argentite.
Lead-grey.
Black,
6-9-7-4
Readily fusible&
Soluble in
Local and
shining.
reduced to a bead
HNOs,pre-
rare; mal-
of silver.
ciptd. by
leable.
HC1, color-
less solutn.
Stephanite.
Black.
Black.
6-2-6-3
Readily fusible;
white coating on
As Argen-
tite, color-
Local and
rare; brit-
support ; bead of
less solu-
tle.
silver if treated
tion.
with soda.
CHAPTER IL— DETERMINATIVE.
21
GROUP X. (Continued.)
Name.
Colour.
Streak.
Sp. Gr.
Behaviour on
Charcoal.
Solubility.
Remarks.
Polybasite.
Black.
Black.
6-0-6-2
Readily fusible;
As Argen-
A doubtful
white coating ;
tite, green
British
bead of Ag. with
soda.
solution.
species.
Chalcocite.
Lead-grey.
Greyish-
black.
5-5-5-8
Keadily fusible;
bead of copper ;
Decompsd.
by Htf03,
Common,
but local.
sulph. odour.
green solu-
tion.
CoveUite.
Dark blue.
Black.
3-8-4-6
Keadily fusible;
As Chalco-
Local and
combustible in
cite.
rare.
part ; bead of
per ; sulphure-
ous odour.
Erubescite.
Purplish,
mottled, or
Do.
4-4-4-5
As Chalcocite,
but requires ad-
Do.
Local, but
not un-
variegated.
dition of borax
common.
for reduction ;
slag gives iron
reactions.
Chalcopy-
Yellow or
Greenish-
3-5-4
As Erubescite ;
Do.
Common.
rite.
variegated.
black.
but less easily
reduced to cop-
per ; fused mass
is magnetic.
Domeykite
Greyish or
Black and
4-5-7'5
Fuses readily ;
Partially
Local and
(Condur-
brownish-
shining.
yields strong al-
soluble in
rare.
rite).
black.
liaceous odour &
abundant white
HNO?,grn.
solution.
coating ; reduced
to a bead of cop.
Tennantite.
Lead - grey
to iron-
Dark red-
dish-brown
4-3-4-5
Fuses readily ;
strong alliaceous
As Domey-
kite.
Local and
rather
black.
odour ; white
rare, oc-
coating ; bead of
curs usu-
cop. with fluxes.
ally in
minute
tetrahed.
crystals.
Fahlerz.
Grey to
Dark red-
4-5-5-2
Fuses readily ;
Very much
Local, but
iron-black
dish-brown
white coating ;
as Tennan-
not very
often iri-
or black.
usually no allia-
tite.
rare.
descent.
ceous odour ; bd.
cop. with fluxes.
Bournonite.
Lead-grey.
Greyish-
57-5-9
Fuses readily ;
Partially
Local, but
black.
sulphureous sol. in hot
not very
odour ; yellow i HNO^ ; a
rare ;very
coating; bead of
white ppt.
brilliant.
cop. with fluxes.
on addi-
tion of
H2S04.
Stannite.
Greyish or
Black.
4-3-4-6
Fuses readily to
Decompsd.
Local, but
black.
a brittle magne-
by hot
not rare.
tic bead; white
HN03,grn.
coating ; sulphu-
solution.
reous odour.
Wittiche-
Tin -white
Do.
4-3-5
Fuses readily ;
Soluble in
A doubtful
nite.
to steel-
dark yellow coat-
hotHN03;
British
grey.
ing ; sulphure-
white ppt.
species.
ous odour ; bead
if diluted
of copper with
with much
difficulty.
water.
22
CHAPTER II.— DETEEMINATIYE.
GKOUP X. (Continued.)
Name.
Colour.
Streak.
Sp. Gr.
Behaviour on
Charcoal.
Solubility.
Remarks.
Bismuthi-
Lead- grey,
Black.
6-4-6-6
Fuses readily ;
Decompsd.
Local and
nite.
often a
dark yellow coat-
by hot
rare ; ge-
yellow tar-
ing ; sulphure-
HNOspre-
nerally in
nish.
ous odour ; brit-
cipitated
brilliant
tle bead of bis-
by water.
needles.
muth.
Galena.
Lead-grey.
Do
7-2-77
Fuses readily ;
Decompsd.
Common.
sulph. odour ;
by hot
bead of lead.
HN03.
1'entlandite
Bronze-yel-
Dark
4-6
Fuses readily to
Soluble in
Local and
low or
brown.
a dark brittle
HNC-3,
rare.
brownish.
magnetic mass ;
forming a
with borax yields
greenish-
iron reactions ;
yellow so-
sulph. odour.
lution.
Wolfram.
Dark grey-
Do.
7-7-6
Infusible, or fusi-
Decompsd.
Local, but
ish, or
ble with great
by Aqua
not rare
brownish -
difficulty ; decre-
Regia, de-
usually ;
black.
pitates strongly.
positing
more than
yel. tungs-
tic anhyd.
5-0.
Manganite.
Greyish-
Dark
4-2--1-4
Infusible ; Mn
Soluble in
Local and
black.
brown or
reactions with
warmHCl.
rath, rare
black.
borax.
Pyrolusite.
Bluish-
Black.
4-7-5-0
Do.
Soluble in
Local, but
black.
warm HC1,
rather
giving off
common ;
H2S.
soils the
fingers.
GROUP XI.— COLOUR VARIOUS; STREAK BLACK OR VERY DARK; H. FROM 5 TO 6.
(Scratched with a knife, but not easily.)
Name.
Colour.
Streak.
Sp. Gr.
Behaviour on
Charcoal.
Borax Bead.
Remarks.
Chromite.
Brownish-
Brown.
4-4-4-5
Infusible.
Green both
Local and
black.
flames.
rare, in
grains
imbedded
in serp.
Cobaltite.
Tin - white
Greyish-
6-6-3
Fusible to a dark
Blue, both
Local and
or red-
black.
brittle magnetic
flames.
rare.
dish.
bead ; alliaceous
and sulphureous
fumes.
Smaltite.
Greyish-
Black.
6-4-7-7
Fusible to a dark
Do.
Not un-
black.
brittle magnetic
common.
bead ; alliaceous
odour and white
coating.
Mispickel.
Tin -white
Do.
6-6-3
Fuses readily to
Reddish-
Common
to steel-
a dark brittle
yellow OF,
in tin
grey.
magnetic bead;
bottle-
mines.
alliaceous and
green RF.
sulph. odours ;
white coating.
CHAPTER II.— DETEKMINATIVE.
23
GEOUP XL (Continued.)
Name.
Colour.
Streak.
Sp. Gr.
Behaviour on
Charcoal.
Borax Bead.
Remarks.
Leucopyrite
Tin -white,
Black or 6 '9-7 '4
Fuses readily to
As Mispic-
Not un-
often a
greyish. ,
a magnetic bead ;
kel.
common
brown
strong alliace-
in tin
tarnish.
ous odours.
mines.
Magnetite.
Dark brown
Black.
4-9-5-2
Infusible.
Do.
Local and
or black.
rather
rare, of ten
strongly
magnetic.
Ilmenite.
Steel - grey
or black.
Brown to 4 -6-5-0
black. |
Do.
Yellow OF,
brown RF.
Local, but
not very
rare.
Psilomelane
Greyish-
Brownish-
5-6
Do.
Amethyst-
Local, not
black.
black and
ine OF,
uncom.
shining.
colourless
RF.
Niccolite.
Copper-red
Brownish-
6-6-7-3
Fuses easily to a
Variable ;
Local and
black.
brittle globule ;
reactions
rare.
strong alliace-
for nickel
ous odours.
and iron.
Wolfram.
Dark grey-
Dark brown
7-7-6
Infusible, or fusi-
Reddish-
Local, but
ish or
ble with great
yellow OF,
not rare.
brownish-
difficulty ; decre-
darker on
black.
pitates strongly,
cooling.
and separates in-
to thin scales.
GROUP XII.— COLOUR VARIOUS; STREAK WHITE OR VERY LIGHT; H. BELOW 5.
(Easily scratched with a knife.)
Name.
Sp. Gr.
Behaviour on Charcoal.
Solubility.
Remarks.
Anglesite.
6-1-6-4
Fuses easily ; sulphure-
Infusible in acids.
Local and rare.
ous odour ; bead of
lead.
Cerussite.
6-4-6-5
Easily reduced to a
Soluble with effer-
Local, but not
bead of lead.
vescence in HC1
very rare, usu-
or HN03.
ally acicular.
Cromfordite.
6-6-3
Fuses easily to a white
Partly soluble with
Only one Cornish
globule, which crys-
effervescence in
specimen known
tallizes on cooling ; in
HN03.
to have occurred
RF a bead of lead and
Mimetite.
7-7-3
white coating.
Fuses easily ; strong
alliaceous odour and
Partly soluble in
HN03.
Local, but not un-
common in lead
bead of lead.
mines.
Pyromorphite.
6-5-71
Fuses easily ; crystal-
Do.
Not uncommon
lizes on cooling ; with
in lead mines.
borax yields a bead of
lead, but not easily.
Bismuth.
9-6-9*8
Very readily fusible ;
Soluble in HN03 ;
Local, but not
coats support yellow.
precipitated on
addition of water.
very rare.
24
CHAPTER II.—DETEEMINATIYE.
GEOUP XII.— (Continued.)
Name.
Sp. Gr.
Behaviour on Charcoal.
Solubility.
Remarks.
Agnesite.
6-9-7
Very readily fusible ;
Soluble (with effer-
Local and very
yellow coating ; grey
ves.?) in HN03 ;
rare.
brittle bead of bis-
precip. on addi-
muth.
tion of water.
Valentinite.
5-5-5-6
Fusible and volatile ;
Soluble in Aqua
Local and rare.
white coating, no al-
Regia, re-precip.
liaceous odour.
on addition of
water if concen-
trated.
Senarmontite.
5-2-5-3
Do.
Do.
Do.
Olivenite.
3-9-4
Readily fusible ; strong
Soluble in HN03
Local, but not
alliaceous odour,
white coating ; bead
except As203.
very rare ; streak
usually very
of copper if treated
light green.
with soda.
Pharmacoside-
2-9-3
Readily fusible ; allia-
Mostly soluble in
Local and rare ;
rite.
ceous odour, white
occurs usually in
coating; brittle mag-
minute cubes of
netic slag which gives
iron reactions.
a green colour.
Scorodite.
3-1-3-3
Much like the preced-
Do.
Local and rare ;
ing.
occurs usually
in very light
green prisms.
Vivianite.
2-6-2-7
Fuses readily to a dark
Do.
Local, but not
magnetic bead ; with
very rare; streak
borax yields iron reac-
soon becomes
tions.
blue, though
white at first.
Wavellite.
2-3-2-4
Fuses to a white opaque
Soluble in HC1 and
Local, but not
mass which turns blue
HN03.
very rare, usual-
when treated with Co.
ly in radiated
masses.
Natrolite.
2-2-2-3
Fuses readily, colours
Decomposed by
Very rare.
flame yellow, white
HC1, leaving gela-
residue, blue with Co.
tinous silica.
Stilbite.
2-2-2
Do.
Do.
Do.
Asbestos.
2-9-3-4
Fusible, but not readi-
Insoluble in HC1.
Not uncommon in
ly ; usually turns blue
some districts.
with Co.
Schiller Spar.
2-6-2-8
Fusible, but not readi-
Decomposed by
Not uncommon in
ly ; pinkish if treated
with Co.
H2S04, less readi-
ly by HC1.
serpentine.
Serpentine.
2-4-2-6
Do.
Do.
Very common in
some districts.
Agalmatolite.
2-4-2-9
Infusible ; blue with Co.
Decomposed by
Local, but not
warm H2SC>4 ;
very rare.
scarcely acted
upon by HC1.
Chiastolite.
2-9-3-4
Do.
Insoluble in HC1 or
A doubtful Corn-
HN03.
ish species.
Pinite.
27-2-9
Infusible, or fusible
Slightly acted on
Local, but not
with great difficulty;
by HC1.
uncommon.
blue with Co.
Allophane.
1-8-1-9
Do.
Decomposed by
Local and rare.
HC1.
Schrotterite.
1-9-21
Infusible, or fusible
Decomposed by
A doubtful Corn-
with great difficulty ;
HC1.
ish species.
blue with Co.
Steatite.
2-2-2-8
Infusible ; pink or red
Scarcely affected
Local, but not
with Co.
by HC1, decom-
uncommon.
Talc.
2-6-2-8
Do.
posed by H2S04.
Do,
Do.
CHAPTER II.— DETEEMINATIVE.
25
GROUP XII. (Continued. )
Name.
Sp. Gr.
Behaviour on Charcoal.
Solubility.
Remarks.
Magnesite.
2-8-3-1
Infusible ; pink with
Soluble with effer-
A doubtful Corn-
Co.
vescence in HCL
ish species.
Blende.
3-9-4-2
Infusible ; decrepitates
Soluble in strong
Very common.
strongly ; sulphureous
HC1 or HX03;
odours, often white
gives off HaS.
coating, which turns
green with Co.
Calamine.
4-4-5
Infusible ; green with
Soluble with effer-
Local and rare.
Co.
vescence in HC1.
Calcite.
2-5-2-8
Infusible ; glows with a
Soluble with effer-
Not uncommon.
bright light ; becomes
vescence in dilute
alkaline.
HC1.
Aragonite.
27-3-0
As Calcite, but falls to
Do.
Very rare and
powder at a low tem-
local.
perature.
Dolomite.
2-8-31
Infusible; becomes al-
Do.
Not uncommon.
kaline.
Chalybite.
37-3-9
Infusible, but turns
Slowly soluble in
Very common.
black and magnetic.
HC1, with efferves-
cence.
Barytes.
3-4-7
Fusible at about 3 ;
Insoluble in HC1
Local, but not
tinges flame yellow-
until after heat-
very rare.
ish-green.
ing in RF.
Celestite.
3-8-4
Fusible at about 3 to a
Do.
Local and rare.
white mass ; if mois-
tened with HC1 co-
lours flame bright red.
Chrysocolla.
2-2-2-3
Infusible ; with soda
Soluble in HC1,
Local, but not
effervesces and yields
leaving gelati-
very rare.
a bead of copper.
nous silica.
Chloropal.
17-2-1
Fusible with difficulty
Decomposed by
Do.
or infusible ; turns
HC1, leaving ge-
black and magnetic.
latinous silica.
Churchite.
3-0-3-1
Infusible ; becomes
—
Very rare.
opaque.
GROUP XIII. — COLOURS VARIOUS ; STREAK WHITE OR VERY LIGHT ;
H. FROM 5 TO 6.
(Scratched with a knife, but not easily.)
Name.
Sp. Gr.
Matrass.
On Charcoal.
Solubility.
Remarks.
Natrolite.
2-2-2-3
Yields water.
Fuses readily ;
Decomp. by
Very rare.
colours flame yel-
HC1, leaving
low, white resi-
gelatinous
due; blue with
silica.
Co.
Analcite.
2-0-2-3
Do.
Do.
Do.
Of very doubtful
occurrence.
Childrenite.
3-2
Do.
Infusible ; with
Slowly sol. in
Local and rare.
boraxyieldsiron
HC1.
reactions.
Porcellanite.
2-6-2-8
Do.
Fuses with some
Slightly act-
Of very doubtful
difficulty ; blue
ed upon by
occurrence.
with Co.
HC1.
CHAPTER II.— DETERMINATIVE.
GROUP XIII. (Continued.)
Name.
Sp. Gr.
Matrass.
On Charcoal.
Solubility.
Remarks.
Babingtonite.
3-3-3-5
Anhydrous.
Fusible ; alkaline Insoluble in
Local, but not
reaction after
HC1 or
very rare.
heating ; with
HN03,
borax iron reac-
tions.
Amphibole.
2-9-3-4
Do.
Often fusible to
Do.
Not uncommon;
a dark magnetic
often green and
mass.
radiated.
Pyroxene.
3-2-8-5
Do.
Do.
Do.
Local, but not
very rare.
Orthoclase.
2-6
Do.
Fusible with diffi-
Do.
Common in gra-
culty, or infusi-
nite ; cleavages
ble.
at right angles.
Albite.
2-6-2-7
Do.
Fusible ; colours
Do.
Probably not un-
flame strongly
common in gra-
yellow.
nite ; cleavage
inclined.
Scapolite.
2-6-2-8
Do.
Fusible ; blue
Do,
Local and rare.
with Co.
Saussurite.
2-7-3-4
Do.
Fusible with dif-
Do.
Local, but not
ficulty, or infu-
rare.
sible.
Apatite.
3-2-3-3
Do.
Fuses with dif-
Slowly sol. in
Local and rare.
ficulty, or infu-
HC1 or
sible.
HN03.
Titanite.
3-4-3-6
Do.
Do.
Decomposed
Do.
by HC1 or
HN03.
Scheelite.
5-9-6-2
Do.
Do.
Soluble, ex-
Do.
cept yellow
tungstic an-
hydride, in
HC1.
Rhodonite.
3-4-3-7
Do.
Do.
Soluble, ex-
Local, but not
cept silica,
rare.
in HC1.
OROUP XIV.— COLOURS VARIOUS ; H. = 6 AND UPWARDS.
(Cannot be scraiched with a knife.)
Name.
Hard-
ness.
Sp. Gr.
Common Colours of
Cornish or Devonshire
specimens.
Remarks.
Quartz.
•Calcedony.
Jasper.
7
6-7
6-7
2-5-2-8
2-6
2-63
Often colourless, or
white and opaque ;
sometimes tinged pur-
ple (A methyst), yellow
(False Topaz), or
brown ; rarely green.
Often bluish or yellow-
ish ; sometimes white
and opaque on the
outside, and nearly
black within.
Usually red, brown,
or black, sometimes
dark green.
Very common ; best known hy
its hardness, want of cleavage,
and insolubility in all acids
except HF ; often crystallized
in hexagonal prisms.
Much less common than quartz ;
usually botryoidal or stalac-
titic ; never crystallized ; usu-
ally translucent, but not
transparent.
Not very rare ; never crystal-
lized ; nearly or quite opaque.
CHAPTER II.— DETERMINATIVE.
GROUP XIV. (Continued.)
Name.
Hard-
ness.
Sp. Gr.
Common Colours of
Cornish or Devonshire
specimens.
Remarks.
Saussurite.
6
2-7-3-4
Usually greenish or
Local, but not very rare ; in
reddish.
Britain not known out of the
Lizard district.
Orthoclase.
6
2-5-2-6
Usually pale flesh-
Very common in granite ; best
coloured ; pink or red
known by its perfect rectan-
sometimes.
gular cleavages.
Albite.
6-7
2-6-27
Usually white or cream-
Less common than Orthoclase ;
coloured.
cleavages make angles of
93o 36' and 86° 24'.
Amphibole.
5-6
2-9-3-4
Usually dark green.
Common in a massive condition ;
rarely crystallized ; fusible
more or less readily.
Pyroxene.
4-6
3-2-3-3
Mostly dark green or
Usually massive ; much less
nearly black.
common than Amphibole : re-
ported from St. Just, but it is
doubtful whether the typical
variety has occurred in Corn-
wall or Devon.
Hypersthene.
4-6
3-2-3-6
Mostly dark brown.
Reported from the Lizard dis^
trict, but it is doubtful whether
true Hypersthene has been
found there.
Opal.
5'5-6-S
1-9-2-3
Mostly of light colours.
Local and rather rare ; never
crystallized ; yields water in
matrass, and is partially solu-
ble in KHO.
Isopyre.
5'5-6-5
29-3-0
Usually dark brown or
Local and rare ; not known, to
nearly black.
crystallize ; somewhat vitreous
in appearance.
Rhodonite.
5-6
3-4-3-7
Usually -pink or rose-
Local, but not very rare, in a
red.
massive condition ; fusible
with a strong heat, and yields
manganese reactions.
Tourmaline.
7-7-5
2-9-3-3
Usually black, dark
Common ; usually in indistinct
brown, or dark green.
prisms, or radiated masses.
Garnet.
6-5-7-5
3-1-4-3
Usually brown or
Local and somewhat rare ; oc-
brownish-yellow.
curs in crystals like Figs. 3, 5,
19, 25, 26.
Axinite.
6-5-7
3-3-3
Brownish.
Best known by its unsymme-
trical, sharp-edged, brilliant,
tabular crystals ; local and
somewhat rare.
Anatase.
5-5-6
3-8-4
Mostly brownish ; lus-
Local and rare ; best known by
tre semi-metallic.
the form of its crystals, see
Figs. 72, 73, 234 ; with borax
yields titanium reactions.
Brookite.
5-5-6
4-4*2
Brownish ; thin plates
Local and very rare ; crystals
reddish ; lustre semi-
like Fig. 147 ; with borax like
metallic.
Anatase.
Rutile.
5-5-6
4-2-4-8
Brownish or reddish ;
Local and very rare, or doubt-
lustre semi-metallic.
ful ; with borax like Ana-
tase.
Cassiterite.
6-7
6-8-7
Greyish, brownish, or
Common ; easily known by its
black ; lustre semi-
hardness and high specific
metallic.
gravity.
Pyrites.
6-6-5
4-8-5-1
Yellow ; lustre metallic.
Common ; often occurs in cubes
or pentagonal dodecahedrons.
Marcasite.
6-6-5
4-8-5-1
Do.
Not so common as Pyrites, best
distinguished by the different
form of its crystals.
Braunite.
6-6-5
4-7-4-8
Black or dark-grey ;
Very doubtful as a British spe-
lustre metallic.
cies ; with borax yields man-
ganese reactions.
28
CHAPTER II.— DETEEMINATIVE.
GROUP XIV. (Continued.)
Name.
Hard-
ness.
Sp. Gr.
Common Colours of
Cornish and Devonshire
specimens.
Remarks.
Chondrodite.
6-6-5
31-3-3
_
Very rare, if not doubtful ;
occurs in small, highly modi-
fied imbedded crystals.
Topaz.
8
3-4-3-6
Colourless, or slightly
tinted with blue,
Local and very rare ; in longi-
tudinally striated prisms, with
green, or yellow.
Cassiterite, Apatite, Fluor, or
Quartz.
Beryl.
7-5-8-0
2-6-2-8
Colourless, or slightly
tinted with green or
Local and very rare, as hex-
agonal prisms, imbedded in
blue.
Granite.
Prehnite.
6-7
2-9-3
Usually pale green.
Local and very rare ; fusible
with effervescence at about 3.
Epidote.
6-5
3-3-5
Usually green or brown.
Local and very rare : fusible
more or less readily ; occurs
imbedded in Quartz or on
Hornblende rock.
Andalusite.
7-7-5
2-9-3-4
Usually dull white or
Local and very rare ; occurs in
Staurolite.
7-7-5
3-4-3-8
greyish.
Usually reddish-brown
square prisms.
Local and very rare, if not
or black.
doubtful.
GROUP XV.— COLOUR VARIOUS; COMBUSTIBLE OR VOLATILE.
(If heated on Charcoal, burn away or pass off in vapour.)
NOTE. — Many sulphides take fire momentarily, but they always leave a considerable
quantity of incombustible mutter.
Name.
Colour.
Sp. Gr.
Solubility.
Remarks.
Bitumen.
Dark brown or
1-1-2
Partly soluble
Local and rare ; usually
black.
in ether or
more or less plastic.
alcohol.
Retinite.
Brown or yellow-
1-1-2
Do.
Local, not very rare ; brit-
ish-brown.
tle ; found only at Bovey
Tracey.
Arsenic.'
Dark steel grey.
5-9-6-0
Soluble in HC1.
A doubtful species.
Arsenolite.
White, or pale yel-
3-6-3-7
Do.
Local and rare ; completely
low.
volatile.
Graphite.
Lead-grey or black.
1-8-2-0
Insoluble in
acids.
Local and rare ; burns away
slowly without flame.
Sulphur.
Yellow.
2-2-1
Do.
Local and very rare ; burns
with sulphureous odour.
Pigotite.
Brown.
—
Partly soluble
Local, but probably not
in HC1. 1 very rare.
CHAPTER III.— DESCKIPTIVE. 29
CHAPTER III.
DESCRIPTIVE.
A full description of a mineral would involve a knowledge of all its properties,
as well as the conditions of its occurrence and the mode of its formation. In
this sense no mineral has yet been described ; perhaps never will be. In the
second part of this work I have endeavoured to indicate by the type in which
the name is printed the comparative abundance or rarity of the minerals
described. Thus, very common minerals, as PYRITES ; minerals which are
less common, as CALCITE ; and those which may be regarded as rare, as
OLIVENITE, are at once indicated by their type. A further distinction had
been intended for the very rare ones, as TOPAZ, but by an oversight this was
neglected until too late.
The characters of the minerals are then given, as far as possible in the
following order: —
Synonyms, Frangibility, Streak,
Form, Diaphaneity, Phosphorescence,
Cleavage, Lustre, Hardness,
Structure, Colour, Specific Gravity.
The best marked varieties are then described (Var.}, after which the chief
blowpipe and chemical reactions are indicated (B., etc.). The chemical composi-
tion (Comp.) is next given, together with all the analyses of specimens from
Cornwall or Devon which the author has been able to procure. In most cases
formulae of several kinds are added in accordance with a theoretical composition.
The atomic weight and symbols used in the f ormulse are given in a " Table of
the Elements," which closes this chapter. The localities (Loc.) are then stated
as fully as possible, and certainly much more so than in any work previously
issued. Especial care has been taken to avoid errors in this respect ; and it is
believed that although there may be many omissions, very few of the localities
stated are erroneous. In the West of Cornwall many are given from the
author's personal knowledge. Next, a general indication of the extent of the
distribution of the species is given ; then, often some simple means of distin-
guishing it from minerals which it somewhat resembles, and mention is made of
the minerals or rocks with which it is especially associated. A table of the
angles of the crystals, with reference to the figures in Plates 1 to 10, is then
given, for which the author is mostly indebted to Messrs. Greg and Lettsom's
Manual of the Mineralogy of Great Britain and Ireland, with occasional aid
from Brooke and Miller, Dana, and Nicol.
In future discoveries of minerals the author would suggest to the discoverers
that they should particularly observe the minerals with which the specimens
are associated, and, if first seen in situ, that they should carefully observe the
position of the crystals, with reference to the "foot-wall," " hanging- wall," or
"back" of the lode, or the "joints" of the quarry.
In some instances the names given to minerals have reference, either to some
supposed peculiarity of the species, or of its mode of occurrence. I therefore
give a list of those which occur in the district under consideration, with short
remarks upon each.
NOMENCLATURE OF MINERALS OCCURRING IN CORNWALL
OR DEVONSHIRE.
(NAMES OF VARIETIES IN ITALICS.)
Actinolite. Gr. Actinotos, radiated ; lithos, a stone.
AGALMATOLITE. (Gr. Agalma, an image ; lithos, a stone.) Figure-Stone. So
called because it is carved into figures by the Chinese.
Agate. Named from its occurrence near the river Achates, in Sicily.
AGNESITE. So called because it was found at St. Agnes, Cornwall.
ALBITE. (Lat. Alba, white.) First described by Wallerius, in 1747.
30 CHAPTER III.— DESCEIPTIVE.
ALLOPHANE. (Gr. Allos, different; phaino, I appear.) First described by
Stromeyer, in 1816.
Amethyst. (Gr. A, priv.; methystos, drunkard.) From its supposed virtue of
preventing intoxication.
Amianthus. (Gr. A, priv.; miaino, to soil.) In allusion to the method of
cleaning fabrics made of this mineral by fire.
AMPHIBOLE. (Gr. Amphibolos, doubtful or ambiguous.) In allusion to the
resemblance of the different varieties, or sub-species, to those of Pyroxene.
First described as a variety of Schorl, by Wallerius, 1747.
ANALCITE. (Gr. A, priv.; alkimos, strong; lithos, a stone.) Discovered!
by Dolomieu, at Etna, in 1784 ; named by Gallitzin, in 1801, in allusion to its
feeble electric properties.
ANATASE. (Gr. Anatasis, stretching forth.) First described by Rome de 1'Isle,
in 1783, as a variety of Schorl ; named Anatase by Hauy, in 1801, in allusion
to the frequent lengthened form of the pyramids.
ANDALUSITE. First described (a specimen from Forez) in the "Journal de
Physique," in 1789; named Andalusite, by Delameth, in the same journal, 1798,
from its frequent occurrence in Andalusia.
ANGLESITE. First described by Monnet, in 1779 ; named by Beudant, in
1832, from its occurrence in the Isle of Anglesea.
ANNABERGITE. First described by Cronstedt, in 1758 ; named by Brooke and
Miller, in 1852, from its occurrence at Annaberg.
ANTHRACITE. Gr. Anthrax, carbon.
ANTIMONITE. First described by Basil Valentine (who proved it to contain
sulphur) in 1430 ; named Antimonite, by Haidinger, in 1845.
ANTIMONY. Described Vet-Academineus, Stockholm, 1748.
APATITE. (Gr. Apatao, I deceive.) First mentioned as a variety of Aqua-
marine, by Brunnick, in 1770, and as a variety of Chrysolite, by Rome de l'Isler
1772 ; named by Karsten, in the year 1800, in allusion to its great resemblance
to many other minerals.
ARAGONITE. First described by Davila, 1767 ; defined, separated from Calcite,
on account of its crystallization, and named by Hauy, in 1801, from its
occurrence in Aragon.
ARGENTITE. (Lat. Argentum, silver.) First described by Agricola, 1529 ;
named by Haidinger, in 1845.
ARSENIC. Gr. Arsenikon, masculine.) In allusion to its very strong and
well-defined properties.
ARSENOLITE. First described by Wallerius, in 1747 ; named and defined by
Dana, in 1854.
Asbestos. Gr. A, priv.; sbestos, combustible.
ASBOLANE. (Gr. Asbolaino, I soil like soot.) First observed in 1529 ; named
by Breithaupt, in 1847.
ATACAMITE. First described by Rochefoucauld, Baume, and Fourcroy, in
1786 ; named by Blumenbach, in allusion to its occurrence in the desert of
Atacama, in 1805.
Augite. Gr. Auge, lustre.
AUTUNITE. Described as a variety of Uranite, before 1819, by several
authors ; named by Brooke and Miller, in 1852, in allusion to its occurrence at
Autun.
AXINITE. (Gr. Axine, an axe.) First described as a species of Schorl, by
Schruber, in 1781 ; named by Hauy, in 1779, in allusion to the common form of
its crystals.
Babel Quartz. Named, in allusion to the successive stories of which it is
built up, after the Tower of Babel.
BABINGTONITE. First described by Levy, in 1824, and na,med after Dr.
Babington.
BARYTES. (Gr. Barus, heavy.) First described by Licetus, in 1640; named
Barytite by Delameth, in 1797, in allusion to its high sp. gr.
BAYLDONITE. First described and named after Dr. Bayldon, by Professor
Church, in 1865. Found as yet only in Cornwall.
BERAUNITE. Named by Breithaupt, in 1841, from Beraun, in Bohemia.
BERTHIERITE. Described by Berthier, in 1827, and named Haidingerite ;
named by Haidinger, in the same year, after Berthier.
BERYL. Described by Theophrastus and other ancient writers; defined by
Vauquelin, in 1800.
CHAPTER III.— DESCRIPTIVE. 31
BISMITE. Separated from Bismuthite by Dana, 1868.
BISMUTH. Described by Agricola, 1546.
BISMUTHINITE. First described by Cronstedt, 1758 ; named Bismutbine, by
Beudant, 1832 ; named Bismuthinite, by Dana, 1868.
BITUMEN. Mentioned by Pliny.
BLEINIERITE. Named Blei-Niere, by Karsten, 1800, thus signifying Lead-
Kidney-ite. Dana proposes to name it after Bindheim, its first analyst.
BLENDE. Described by Agricola, in 1546 ; named Bldnde, by Wallerius, in
BOURNONITE. First described by Rashleigh, 1797, having been discovered in
Cornwall ; named after its discoverer, Comte de Bournon, by Jameson, in 1816.
BRAUNITE. First described and named after M. Braun, of Gotha, by
Haidinger, in 1826.
BROCHANTITE. Named and described by Levy, in 1824, after Brochant de
Villiers. Found in Cornwall about the year 1864.
BROOKITE. First described by Soret, 1822 ; named by Levy, in 1825, after
the British mineralogist, H. J. Brooke.
CALAMINE. First described by Agricola, in 1546 ; separated from the Silicate
of Zinc, and named Smithsonite, by Beudant, 1832.
Calc.edony. Named Chalcedonius, by Agricola, in 1546.
CALCITE. Named Kalchstein (Limestone), by Agricola, in 1545 ;* Calcite, by
Haidinger, 1845.
CASSITERITE. (Gr. Kassiteros, tin.) Named Cassiterit, by Beudant, in 1832.
CELESTITE. First described by Schutz, in 1791 ; named from Ccelestis, celestial
from a faint shade of blue often present, by "Werner, 1798.
CERUSSITE. Named Ceruse, by Beudant, in 1832, from the Cerussa (artificial
Carbonate of Lead) of Pliny and Agricola.
CERVANTITE. Defined and named, by Dana, in 1854, from Cervantes, in
'Galicia, Spain.
CHALYBITE. (Gr. Chalybs, iron.) Named by Glocker, in 1847.
CHENEVIXITE. Named by Adam, after the celebrated chemist, Chenevix,
who published its first analysis. Found only in Cornwall.
CHESSYLITE. Described by Wallerius, in 1747 ; named by Brooke and Miller,
in 1852, from its chief locality, Chessy, in France.
CHILDRENITE. Named by Levy, in 1823, after the celebrated mineralogist
Children.
CHLORITE. (Gr. Chloros, green.) Name very ancient.
CHLOROPAL. Named by Bernhardi and Brandes, in 1822.
CHONDRODITE. (Gr. Chondros, a grain.) First described and named by
d'Ohsson, in 1817.
CHROMITE. (Chrome-Stone.) First described by Vauquelin, in 1800; named
thus by Haidinger, in 1845.
CHRYSOCOLLA. (Gr. Chrysos, golden; colle, glue.) Named thus by Agricola,
in 1546.
CHURCHITE. Named by C. G. Williams, in 1865, after its first analyst,
Prof. A. H. Church ; discovered by Mr. Tailing, of Lostwithiel, about 1865, and
not yet found out of Cornwall.
CLINOCLASE. (Gr. Klino, to incline, and klao, to cleave.) First described by
Klaproth, in 1801, in allusion to its inclined cleavages. Named thus by
Breithaupt, in 1830.
COBALTITE. (Ger. Kobold, a mine-demon.) First described by Cronstedt, in
1758; named Cobaltine, by Beudant, in 1832.
CONNELLITE. First described by Rashleigh, in 1802; named by Dana, in
1850, after its first analyst, Connell. Not hitherto found out of Cornwall.
COPPER. (Lat. Cuprum.) A corruption of Cyprium, whence it was anciently
brought.
CORNWALLITE. First described and named by Zippe, in 1845, from its
occurrence in Cornwall. Not found elsewhere.
COVELLITE. Described by Breithaupt, in 1817 ; named by Beudant, after its
discoverer, Covelli, in 1832.
CROMFORDITE. Described as Hornblei, by Karsten, in 1800 ; named by Greg
and Lettsom, in 1858, from its occurrence at Cromford, in Derbyshire.
CRONSTEDTITE. First described and named by Steinmann, in 1821, after the
Swedish mineralogist, Cronstedt
CUPRITE. (Lat. Cuprum.) Named thus by Haidinger, in 1845.
CYANOSITE. (Gr. Kuanos, blue.) Named Cyanose, by Beudant, in 1832.
CHAPTER III.— DESCEIPTIVE.
DEMIDOFFITE. Named after Demidoff, by Nordensk, in 1856. Dana regards
it as a variety of Chrysocolla.
DIALLOGITE. Named Dialogite, by Jasche, in 1817.
DOLOMITE. Named Dolomie by Saussure, in 17%, after the celebrated
Dolomieu, who first called attention to some of its peculiar properties, in 1791.
DOMEYKITE. First described by Zinken, in 1837 ; named by Haidinger, in
1845, after the celebrated mineralogist, Domeyko.
EPIDOTE. Described by de 1'Isle, in 1783, as a variety of Schorl; named
Epidote, by Hauy, in 1801.
ERINITE. Named by Haidinger, in 1828, from its supposed occurrence in
Ireland, but shewn by Professor Church to be a Cornish species.
ERUBESCITE. First described by Henckel, in 1725 ; named Erubescite, by
Dana, in 1850.
ERYTHRITE. (Gr. Eruthros, red.) First described by Briickmann, in 1727;
named Erythrine, by Beudant, in 1832.
FAHLERZ. (Ger. Fahl, ash-coloured; erz, ore.) First described by "Wallerius,
in 1747, and named by him Falerts.
felspar. (Ger. Feldspath, rock-spar.) A very ancient name.
FLUELLITE. First described and named from the presence of Fluorine, by
Levy, in 1824. Not found out of Cornwall.
FLUOR. (Lat. Fluere, to flow.) First described and the name applied by
Agricola, in 1529, in allusion to its value as a flux.
GALENA. (Gr. Galeo, I shine.) First named and described by Agricola,
in 1546.
GARNET. (Fr. Grenat, a grain.) Described as a variety of Anthrax, by
Theophrastus ; named Granat, by Wallerius, in 1747.
GILBERTITE. Named and described, by Thomson, Min. I., p. 236.
GLAUOONITE. (Gr. Glaucos, bluish -green.) First described and named, by
Keferstem, in 1828.
GOLD. A very ancient name.
GOSLARITE. First described by Agricola, in 1546 ; named by Haidinger, from
its first known locality, Goslar, in 1847.
GRAPHITE. (Gr. Grapho, I write.) Described by Bromell, in 1739; named
Graphite, by "Werner, in 1789.
GYPSUM. (Gr. Gypsos, lime.) Described by Herodotus and Theophrastus.
(325 B.C.) Named Gypsum, by Agricola, in 1546.
HALITE. Named by Glocker, in 1847.
HEMATITE. (Gr. Raima, blood.) Described by Theophrastus (325 B.C.), and
named Aimatites.
HISINGERITE. First described and named by Berzelius, in 1828.
HYPERSTHENE. (Gr. Hyper, above, or excess ; sthenos, strength.) First
described as Labrador Hornblende, by Werner, in 1789 ; named by Hauy, in 1803.
ILMENITE. First described and named Menachanite, by Wm. McGregor, in
1791 ; named Ilmenite, by Kupfer, in 1827 ; re-named Menaccanite, by Dana,
in 1868.
ISOPYRE. (Gr. Isos, equal, and Pyr, fire.) First described and named by
Turner, in 1827.
JAMESONITE. First described by Jameson, in 1820; named after him, by
Haidinger, in 1823.
JASPER. A very ancient name.
JOHANNITE. Discovered, by John, in 1821 ; named after him, by Haidinger,
in 1830.
KALINITE. Known as alum for a very long period ; named by Dana, in 1868.
KAOLIN. Described by Werner, in 1780 ; the name is Chinese.
KERATE. (Gr. Keras, a horn. ) Described by Gesner, in 1565 ; named by
Haidinger, in allusion to its horny nature, in 1845.
LANGITE. First described by Maskelyne, and named after Dr. Lang, in 1864.
LEPIDOLITE. (Gr. Lepis, a scale.) First described by Yon Born, in 1791 ;
named by Klaproth, in 1794.
LEPIDOMELANE. (Gr. Lepis, and melas, black.) Described and named by
Hausmann, in 1840.
LEUCOPYRITE. (Gr. Leucos, white, and pyrites.) First described by Jameson,
in 1820 ; named by Shepard, in 1835.
LIBETHENITE. Described by Leonhardt, in 1812 ; named by Breithaupt, in
allusion to its chief locality, Libethen, in 1823.
CHAPTER III — DESCEIPTIYK 33
LlMONiTB. Described very anciently. Separated from Hematite and named,
by Beudant, in 1832, from Leimon, a meadow; more particularly applicable to
Bog Iron Ore.
LINARITE. First described, and named from its first locality, Linares, in
Spain, by Brooke, in 1822.
LIROCONITE. (Gr, Leiros, pale, and konis, dust.) First described by Bournon,
in 1801 ; named by Mohs, in allusion to its pale streak, in 1822.
LUNNITE. First described by Klaproth, in 180 L ; named by Bernhardi,
in 1844.
MAGNESITE. Described by Werner, in 1803 ; named by Karsten, in 1808.
MAGNETITE. So named, from its magnetic properties, by Haidinger, in 1845.
The mineral was known by the ancients.
MALACHITE. (Gr. Malakos, soft.) Included with Chrysocolla by Theo-
phrastus; named Molochit, by Agricola, in 1546; Malachit, by Wallerius,
in 1747.
MANGANITE* First described by De Lisle, in 1783 ; named Manganite, by
Haidinger, in 1827, in allusion to the manganese contained in it.
MARCASITE. This name, which is of Moorish origin, was formerly applied
to ordinary crystallized Pyrites. The present species was distinguished, and
the name restricted, by Haidinger, in 1845.
MELACONITE. (Gr. Melas> black, and konis, powder.) First described by
Werner, in 1789 ; named by J. N. Hust, in 1841.
MELANTERITE. (Gr, Melas, black.) Known to the ancients by the name
Melanteria. Name adopted by Beudant, in 1832.
MESOLITE. First described by Fuchs and Gehlen, in 1816.
MILLERITE. First described by Werner, in 1789 ; named by Haidinger, in
1845, in honour of Dr. Miller, the eminent crystallographer.
MIMETITE. (Gr. Mimetes, imitator.) First described by Wallerius, in
1748 ; named Mimitese, by Beudant, in 1832, on account of the resemblance of
its crystals to those of Pyromorphite ; named Mimetit, by Haidinger, in 1844*
MISPICKEL. Described by Agrioola, in 1546, as Mist-puckel; Mispickel, by
Wallerius, in 1747. Name Arsenopyrite proposed by Dana, in 1868.
MOLYBDENITE. Included with Graphite by Wallerius, in 1747; named
Molybdaena by the discoverer of its metallic base, Hielm, in 1782; Molybdenite,
by Brongniart, in 1807.
MUSCOVITE. Named by Dana, in 1850, in allusion to its common
occurrence in some parts of Russia (Muscovy).
NATROLITE, First described by Cronstedt, in 1758. Named by Klaproth,
in 1803, in allusion to the soda (natron) contained in it,
NICCOLITE. First described by Hiarne, in 1694; named Nickeline, by
Beudant, in 1832, in allusion to its contained metal ; named Niccolite, by Dana,
in 1868.
OLIVENITE. Discovered in Cornwall ; first described by Klaproth, in 1786 ;
named Olivenerz, by Werner, in 1789, in allusion to its olive-green colour ;
named Olivenite, by Jameson, in 18<iO,
OPAL. First described by Pliny,
ORTHOCLASE. (Gr. Ortfios, straight, right ; klasis, fracture.) Described by
Agricola, in 1546, Separated from allied species, and named, by Breithaupt, in
1823, in allusion to its rectangular cleavages.
PENTLANDITE. Described by Scheerer, in 1843 ; named, by Dufrenoy, in
1856, after Mr. Pentland.
PHARMACOSIDERITE. (Gr. Pharmakon^ poison, and sideros, iron.) Described
by Kirwan, in 1796 ; named by Hausmann, in 1813, in allusion to its chemical
composition.
PIGOTITE. In some Cornish caves ; first discovered by Johnston (Phil. Mag.,
III., XVII., 382), and named after the Rev. Mr. Pigot.
FINITE. Described by Hoffmann, in 1789, and named from its occurrence m
the galleries of the Pini Mine, at Schneeberg.
PITCHBLENDE. Described by Bruckmanu, in 1727; named Beckblande
or Pitchblende, by Wallerius, in 1747. Name Uraninite proposed by Dana,
in 1868.
PITTICITE. Described by Karsten, in 1808 ; named Pittizit, by Hausmann, in 1813,
PLUMBIC OCHRE. Described by Huot, in 1841, under the name of Massicot.
POLYBASITE, Described and named by H. Rose, in 1829, in allusion to its
many contained bases,
34 CHAPTER ILL— DESCKIPTIYE.
PORCELLANITE. Described with allied species, by Ekeberg, in 1807 ; named
by Von Kobell, in 1853 ; named Ekebergite, by Dana, in 1868.
PREHNITE. Described by Sage, in 1777, as Chrysolite ; defined and named by
Werner, in 1790, after Col. Prehn, who first found the mineral at the Cape of
Qood Hope.
PSILOMELANE. (Or. Psilon, smooth; melan, black.) Described by Wallerius,
in 1747 ; named by Haidinger, in 1827.
PYRAEGYRITE. (G-r. Pyr, tire ; arguros, silver.) Described by Agricola, in
1546 ; named by Glocker, in 1841.
PYRITES. (Gr. Pyr, fire ; ites, for lithos, a stone.) Mentioned by Dioscorides
and Pliny.
PYROLUSITE. (Gr. Fyr, fire, and lusis, decomposition.) Described by Coesal-
pinus, in 1596 ; named and defined by Haidinger. in 1827.
PYROMORPHITE. (Gr. Pyr, fire, and morphe, form.) First described by
Wallerius, in 1748 ; named by Hausmann, in 1813, in allusion to its ready
crystallization after fusion.
PYROXENE. (Gr. Pyr, fire ; zeno, a guest.) Mentioned by Wallerius, in 1747 ;
defined by Demeste, in 1779 ; named by Hauy, in 1799, in allusion to its
occurrence in volcanic regions.
PYRRHOTITE. (Gr. Pyrrhotes, reddish.) Mentioned by Wallerius, in 1747;
named Pyrrotin, by Breithaupt, in 1835 ; Pyrrhotite, by Dana, in 1868.
QUARTZ. Described by Theophrastus, Pliny, and other ancient writers as
Crystallos ; mentioned as Quartz, by Wallerius, in 1747. Origin of name
uncertain.
RETINITE. Occurs only at Bovey Tracey ; described by J. Milles, in 1760 ;
named by Hatchett, in 1804 ; named Retinellite, by Dana.
RHODONITE. (Gr. Rhodon, a rose.) Analysed and described by Ruprecht, in
1782 ; named by Jasche, in allusion to its red colour, in 1819.
RUTILE. (Lat. Rutilus, shining red.) Described as a variety of Schorl by
de Tlsle, in 1783 ; named by Werner, in 1800.
SAUSSURITE. Described by Klaproth, in 1807 ; named by T. de Saussure, in
1806. Name Zoisite, of Brooke (1823), adopted by Dana, in 1868.
SCAPOLITE. (Gr. Scapos, a rod. ) First described by de 1'Isle, in 1783 ; named
Scapolite, by d'Andrada, in 1800. Named and defined as'Meionite, by Hauy,
in 1801 ; name adopted by Dana, in 1868.
SCHEELITE. Referred to by Wallerius, in 1747 ; named Scheelit, by Leonhardt,
in 1821, after the Swedish chemist, Scheele, who discovered Tungsten in this
mineral in 1781.
SCHILLER SPAR. Described and named by Heyer, in 1786 ; included as a
variety of Serpentine, by Dana, in 1868.
SCHORL. (Swedish, Short, brittle.) The old name for Tourmaline.
SCHROTTERITE. First described by Schrb'tter, in 1837 ; named after him, by
Glocker, in 1839.
SCORODITE. (Gr. Scorodon, garlic.) Described by Bournon, in 1801 ; named
by Breithaupt, in 1817, in allusion to its odour when heated before the
blowpipe.
SENARMONTITE. First described by Senarmont, in 1851 ; named by Dana, in
honour of the discoverer, the same year.
SERPENTINE. Mentioned by the ancients as Ophites.
SILVER. (Germ. Silber. ) Known to the ancients.
SMALTITE. Described by Agricola, in 1529 ; separated from Cobaltite, by
Rome de Lisle, in 1772 and 1783, on crystallographic grounds ; named Smaltine,
by Beudant, in 1852 ; Smaltite, by Dana, in 1868.
SMECTITE. Named and defined by Breithaupt, in 1841.
STANNITE. First discovered in Cornwall at Huel Rock; described by Klaproth,
in 1787 ; named Stannine, by Beudant, in 3832 , Stannite, by Dana, in 1868.
STAUROLITE. Described and figured by De Robien, in 1751 ; named by
Delameth, in 1792.
STEATITE. (Gr. Stear, fat.) Discovered at first in Cornwall ; described by
Cronstedt, in 1758 ; named by Kirwan, in 1794 ; named Saponite, by Vanberg,
in 1841, and the name adopted by Dana, in 1868.
STEPHANITE. Described by Agricola, in 1546 ; named by Haidinger, in 1845,
after the Archduke Stephan, Mining Director of Austria.
STIBICONITE. (Stibium, antimony, and konis, a powder.) Described and named
by Beudant, in 1832.
CHAPTER III.— DESCEIPTIVE.
35
STILBITE. (Gr. Stilbe, lustre.) Described as Zeolite, by Cronstedt, in 1756;
named by Hauy, in 1798.
SULPHUR. Known to the ancients ; origin of name unknown.
TALC. Described by Agricola, in 1546, as Talck or Glimmer.
TITANITE. First described by Pictet, in 1787 ; named by Klaproth, in 1795.
TOPAZ. (Gr. Topazios, an island in the Red Sea.) Described as Topaz, by
Wallerius, in 1747.
TORBEENITE. First mentioned by Yon Born, in 1772 ; named Torberit, by
Werner, in 1793, after the chemist, Torbernus Bergmann.
TOURMALINE. Mentioned by Rinmann, and the name applied to the trans-
parent Tourmalines in 1766 ; applied to all the varieties, by Hauy, in 1801.
VALENTINITE. Mentioned by Moncey, in 1783 ; named after Basil Valentine,
the discoverer of Antimony, by Haidinger, in 1845.
VIVIANITE. Mentioned by Cronstedt, in 1758 ; named after J. G. Vivian,
the English mineralogist, who first discovered the English specimens, by Werner,
in 1817.
WAD. Mentioned by Cronstedt, in 1858 ; named by Kirwan, in 1796.
WAVELLITE. First discovered by Mr. I. Hill, of Tavistock, in 1785 ; named
Wavellite, by Dr, Babington, in 1805, after Dr. Wavell, of Barnstaple, who
first analysed it.
WITTICHENITE. Described by Klaproth, in 1807 ; named from its first
locality, Wittichen, Baden, by Von Kobell, in 1853.
WOLFRAM. Mentioned by Agricola, in 1546 ; named Volfram, by Wallerius, in
174? ; named Wolframit, by Breithaupt, in 1832 ; and Wolframite, by Dana,
in 1868.
WOLFRAMITE. First mentioned by Sillimao, in 1822 ; named Wolframine by
Greg and Lettsom, in 1858.
ZIPP^ITE. First mentioned by J. F. John, in 1821 ; named by Haidinger,
after the mineralogist, Zippe, in 1845.
TABLE OF THE ELEMENTS,
SO FAR AS THEY ARE AT PRESENT KNOWN.
(Those printed in capitals are the most important ; those in small capitals of 1
importance ; the remainder are either of rare occurrence or very little known.)
METALLOIDS.
Name.
Symbol.
Atomic or
unit weight.
Physical con-
dition when
uncombined.
Remarks.
BORON.
-B.
11
Solid.
In Schorl and other
minerals.
BROMINE.
Br.
80
Liquid.
In sea water.
CARBON.
C.
12
Solid.
As Graphite, and in Car-
bonates.
CHLORINE.
Cl.
35-5
Gas.
In several Chlorides.
FLUORINE.
F.
19
— .
Chiefly in Fluor Spar.
HYDROGEN.
H.
1
Gas.
In water, and all hy-
drated minerals.
IODINE.
I.
127
Do.
In sea weed.
NITROGEN.
N.
14
Do.
Largely in the air.
OXYGEN.
0.
16
Do.
In the air, and in all
oxides.
PHOSPHORUS.
P.
31
Solid.
In many Phosphates.
Selenium.
Se.
79
Do.
Not known to have oc-
curred in Dev. or Corn.
SILICON.
Si.
28'5
Do.
Abundant in Quartz, and
in numerous Silicates.
SULPHUR.
S.
32
Do.
Abundant in Sulphide*
and Sulphates.
36
CHAPTER HI.— DESCRIPTIVE.
TABLE or THE ELEMENTS.— (Cord.) METALS.
.Name,
Symbol.
Atomic or
unit weight.
Physical con-
dition when
uncombined.
Remarks.
ALUMINIUM.
Al.
27-5
Solid.
Abundant in Felspar and
and Kaolin.
ANTIMONY.
Sb.
122
Do.
Occurs in Antimonite and
other minerals.
ARSENIC.
As.
75
Do.
Abundant in Mispickel
and various Arseniates,
BARIUM.
Ba.
137
Do.
In Barytes.
BISMUTH.
Bi.
208
Do.
Native and in Bismuthi^
nite.
CADMIUM.
Caesium.
Cd.
Cs.
112
133
Do.
Do.
Occurs rarely in Blende.
Not known in Cornwall
or Devon.
CALCIUM.
Ca.
40
Do.
In Calcite and Dolomite,
Cerium.
Ce.
92
Do.
Occurs in Churchite.
CHROMIUM.
Cr.
52-5
Do.
In Chromite.
COBALT.
Co.
58-8
Do.
In Smaltite and a few
other minerals.
COPPER.
Cu.
63-5
Do.
Native, and in many
mineral compounds.
Didymium.
D.
96
Do.
In Churchite; discovered
Glucinum.
GOLD.
G.
Au.
14
197
Do.
Do.
by the spectroscope.
Very rare ; in Beryl.
Native, in stream works,
also in Pyrites.
Indium.
In.
74
Do.
Not known.
Iridium.
Ir.
198
Do.
Do.
IRON.
Lanthanium.
Fe.
L.
56
92
Do.
Do.
Common in many minerals
Not known.
LEAD.
Pb.
207
Do.
Common in Galena and
other minerals.
LITHIUM,
Li.
7
Do.
In mineral waters and in
various Micas.
MAGNESIUM.
Mg.
24
Do.
In Serpentine, &c.
MANGANESE.
Mn.
55
Do.
In Pyrolusite and other
minerals.
MERCURY.
Hg.
200
Liquid.
Not known.
Molybdenum,
Mo.
92
Solid.
In Molybdenite.
NICKEL.
Ni.
59
Do.
In Niccolite and other
minerals.
Niobium.
Nb.
97
Do.
Not known.
Osmium.
Os.
199
Do.
Do.
Palladium.
Pd,
106 '5
Do.
Do.
PLATINUM.
Pt.
197
Do.
Do.
POTASSIUM.
K.
39
Do.
In Felspar, &c.
Rhodium.
Rh.
104
Do,
Not known.
Rubidium.
Rb.
85-5
Do,
Do.
Ruthenium.
Ru.
104
Do.
Do.
SILVER.
Ag.
108
Do.
Native, and in various
SODIUM,
Na.
23
Do.
mineral compounds.
Common in sea water;
also occurs in Albite.
STRONTIUM.
Sr.
87'5
Do.
In Celestite ; rare.
Tantalum.
Ta.
137-5
Do.
Not known.
Tellurium.
Te.
128
Do.
Do.
Thallium,
Tl,
204
Do,
Perhaps occurs in some
j
Cornish Pyrites,
CHAPTER III.— DESCEIPTIVE.
37
TABLE OF THE ELEMENTS.— (Cont.) METALS.
Name.
Symbol.
Atomic or
unit weight.
Physical con-
dition when
uncombined.
Remarks.
Thorium.
Th.
231-5
Solid.
Not known.
TIN.
Sn.
118
Do.
Abundant in Cassiterite,
also in Stannite.
TITANIUM.
Ti.
50
Do.
In Manaccanite and a few
other minerals.
TUNGSTEN.
W.
184
Do.
In Wolfram.
URANIUM.
U.
120
Do.
In Pitchblende and other
minerals.
Vanadium.
V.
51
Do.
Not known.
Yttrium.
Y
68
Do.
Do.
ZINC.
Zn.
65
Do.
Abundant in Blende.
Zirconium.
Zr.
90
Do.
Not known.
CHAPTER IV.
SYSTEMATIC.
Many different methods of mineralogical arrangement have been proposed,
but the chief of those now in use are three, viz. : —
" Chemical," in use at the British Museum, &c.
" Economical," in use at Jermyn-street Museum.
"Mixed," as proposed by Weiss, and adopted by Nicol.
Tables of arrangement, in accordance with these systems, are here given,
together with a table, in which they are arranged according to crystalline form,
as a matter of interest, or for occasional reference.
Name.
Gold Au
Silver Ag
Copper Cu.
1.— C H E M I C A L .
NATIVE METALS.
Symbol. Name.
Symbol.
Bismuth Bi
Antimony Sb
Arsenic .. ..As
Graphite
NATIVE METALLOIDS.
C Sulphur,
Niccolite ..
Domeykite
Argentite...
Chalcocite
Galena
Blende
Covellite...
MiUerite ...
ARSENIDES.
NiAs
Cu3As
SULPHIDES.
AgsS
Cu2S
PbS
ZnS
CuS
NiS
Leucopyrite
Smaltite....
FeAs2
CoAs2
38
CHAPTER IV.— SYSTEMATIC.
SULPHIDES. — (Cont.)
Xame. Symbol.
Pyrrhotite .. FeS or, perhaps, Fe7S8
Pentlandite.. (|FeiNi)S = 2FeS + NiS.
Erubescite .. (§Cu|Fe)S = 2CuS + FeS or FeCu2S3
Pyrites FeS2
Marcasite .. FeS2
Molybdenite. MoS2
Chalcopyrite (CuFe)S2
Stannite .... (|CuFeZn£Sn)S2
Mispickel Fe(SAs)2
Cobaltite Co(SAs)2
Bismuthinite Bi2S3
Antimonite . . . Sb2S3
SULPHANTIMONIDES AND SULPHARSENIDES.
Pyrargyrite... 3AgS + Sb2S3
Jamesonite ... 3PbS + 2Sb2S3 = Pb3S4S9
Berthierite a. 3FeS + 2Sb2S3 = Fe3Sb4S9
Do. b. 3FeS + 3Sb2S3 = Fe3Sb6S12
Do. c. 3FeS + 4Sb2S3 = Fe3Sb8S15
Bournonite... 3(CuPb)S + Sb2S3
Fahlerz 4(CuAgHg)S + (SbAs)2S3
Stephanite ... 5AgS + Sb2S3
'Tennantite ... 4(CuFe)S + As2S3
Polybasite ... 10(AgCu)S + (SbAs)2S3
OXIDES.
Anhydrous.
Cuprite
Melaconite ...
Cu2O
CuO
Hematite Fe2O3
Ilmenite (TiFe)2O3
Bismite Bi2O3
Arsenolite As2O3
Plumbic Ochre. PbO
Valentinite ... Sb2Os
Senarmontite... Sb2O3
Cervantite Sb2O3 -f Sb2O5
Psilomelane ... Mn2O3 essentially
Anatase
Brookite
Rutile
Quartz
Wolframite ,
Magnetite....
Pitchblende ,
Chromite ...
Manganite
Gpethite ..
Limonite ..
Stibiconite
Opal
TiO2
Ti02
Ti02
SiO2
Calcedony ..
Jasper
Cassiterite ..
Pyrolusite ..
Si02
Si02
SnO2
Mn02
W03
Fe3O4 = FeO +
U304 = UO
(FeMgAlCr)304
Hydrous.
Mn2O3 + H2O
Fe2O3 + H2O
Fe2O3 + 2H2O
Fe2O3
U2O3
Sb2O5 + H2O
SiO2 + water in variable proportion.
Asbolane Variable and uncertain.
Wad Do.
Zippseite Do.
CHAPTEB IV.— SYSTEMATIC. 89
SILICATES.
(The composition of silicates varies so much that the formulae are very
complex. A few of the most simple only are given.)
Anhydrous.
Name. Symbol.
Rhodonite MnSiO3
Titanite Ca(SiTi)O3
Amphibole : —
a. Tremolite ... (£CafMg)SiO3
b. Actinolite ... (iCajFe$Mg)SiOa
c. Hornblende... (JOa|FelAl|Mg)SiOa
Pyroxene (JCaiMgjSiOj
Hypersthene (MgFe)SiO3
Babingtonite (FeCa)SiO3
Beryl (AlBe)SiO3 =,Si6O6Al2oviBeo"3
Talc 2MgSiO3 + SiO2
Albite Al2O3Na2O6SiO2 = Si6O8Nao2Al2ovi
Orthoclase Al2O3K2O6SiO2 = Si6O8Ko2 Al2o"
Andalusite Al2O3SiO2
Topaz Al2O3SiO2 with one-fifth of the O re-
placed by F
Chondrodite Silicate of Magnesia, with some Fluorine.
Garnet A complex Silicate of many bases.
Axinite , , Silicoborate of Alumina, Lime & Iron.
Tourmaline ,, ,, Alumina, and many other
Epidote ............... ,, Silicate, Alumina, Lime and Iron.
Scapolite ............... , , „ Lime and Alumina.
Muscovite ............ ,, ,, Potash, Magnesia, Alumina,
and Iron.
Lepidolite ............ „ ,, Potash, Lithia, and Alumina.
Lepidomelane ......... „ ,, Potash, Lithia, Alumina,
Iron, &c.
Porcellanite ......... „ „ Lime, Alumina, and Soda.
Staurolite ............ ,, ,, Alumina and Iron.
Isopyre .................. „ ,, Alumina, Iron, and Lime.
Saussurite ............ Perhaps only impure Silica.
Hydrous.
Steatite ............... MgSiO3 + H2O
Chrysocolla ......... CuSiO3 + 2H2O
Serpentine ......... 2MgSiO3 + MgH2O2 +
Stilbite ............... Silicate of Alumina and Lime.
Prehnite ............ Do. Do.
Natrolite ............ Silicate of Alumina and Soda.
AmJcite ............ Do. Do.
Mesolite ............ Silicate of Alumina, Lime, and Soda.
Kaolin ............... Silicate of Alumina.
Gilbertite ............ Do.
Allophane ............ Do.
Schrotterite ......... Do.
Smectite ............ Do.
Hisingerite ......... Silicate of Iron.
Chloropal ............ Do.
Cronstedtite ......... Do.
Chlorite ............... Silicate of Alumina, Magnesia, and Iron.
Agalmatolite ...... Silicate of Alumina and Potash.
Finite .................. Do. Do.
Glauconite ......... Silicate of Iron and Potash.
Schiller Spar ...... Silicate of Iron and Magnesia.
40
CHAPTER IV.— SYSTEMATIC.
Name.
Wolfram
TUNGSTATES.
Symbol. Name.
FeWO4 Scheelite
Symbol.
CaWO4
CARBONATES.
A nhydrous.
Calcite ......... CaCO3 or COCao"
Aragonite ...... CaCO3
Dolomite ...... (CaMg)CO3
Chalybite ...... FeCO3
Magnesite ...... MgCO3
Calamine ...... ZnCO3
Diallogite ...... MnCO3
Cerussite ...... PbCO3
Agnesite ...... Impure Carbonate of
Bismuth.
Hydrous.
Malachite CuC03 + CuH2O2 Chessylite 2CuC03 + CuH2O2
SULPHATES.
Anhydrous.
Anglesite PbSO4 => SO2Pbo" Celestite . .. SrSO4
Barytes BaSO4
Hydrous.
Gypsum CaSO4 + 2H2O
Cyanosite CuSO4 + 5H2O
Melanterite FeSO4 + 7H2O
Goslarite ZnSO4 + 7H2O
Johannite USO4 + H2O (somewhat uncertain.)
Kalinite (JA1JK)SO4 + 6H2O
Linarite PbSO4 + CuH2O2
Langite CuSO4 + 3CuH2O2 + 2H2O
Brochantite 2CuSO4 + 5CuH2O2
ARSENIATES AND PHOSPHATES.
Anhydrous*
Mimetite 3(Fb3As2O4) + PbCl2
Pyromorphite 3(Pb3P2O4) + PbCl2
Apatite :—
a. Chloroapatite 3(Ca3P2O4) + CaCl2
b. Fluorapatite . 3(Ca3P2O4) + CaF2
Hydrous.
Olivenite Cu3As2O8 + CuH2O2
Clinoclase Cu3As2O8 + 3CuH2O2
Cornwallite— a, ... Cu3As2O8 + 2CuH2O2 + H2O
b. ... Cu3As2O8 + 2CuH2O2 + 3H2O
Erinite Cu3As2O8 + 2CuH2O2
CLalcophyllite— a. Cu3As2O8 + 5CuH2O2 + 7H2O
„ b. Cu3As2O8 + 5CuH2O2 + 9H2O
„ c. Cu3As2O8 + 5CuH2O2 + A12H2O6 + 16H2O
„ d. Cu3As2O8 + 5CuHoO2 + A12H2O6 + 17H2O
Liroconite 2(Cu3 As2O8) +• 2CuH2O2 + A12H2O6 + 19H2O
Chenevixite Cu3As2O8 + Fe3As2O8 + CuH2O2 + FeH2O2 + 4H2O
Bayldonite Cu2PbAs2O8 + CutL,O2 + 2H2O
Annabergite Ni3As2O8 + 8H2O
Erythrite Co3As2O8 + 8H2O
Pharmacosiderite. Fe3As2O8 + 8H2O
Scorodite Fe3As2O8 + 4H2O
Pitticite Fe2As208 + H2SO4
CHAPTER IV.— SYSTEMATIC. 41
II.— ECONOMICAL.
(Adopted at the Museum of Practical Geology, Jermyn-street, London.)
DIVISION I.— NON-METALLIC MINERALS.
CLASS I.— CARBON AND BORON.
Group 1. — Carbon and its Com- Group 3. — Inflammable Salts.
pounds. Group 4. — Boron and its Ccm~
Graphite. pounds.
Anthracite.
Group 2. — Hydrocarbons.
Bitumen.
Eetinite.
CLASS 2.— SULPHUR AND SELENIUM.
Group 1.— Sulphur and its Com- Group 2.— Selenium and its Com-
pounds, pounds.
Sulphur.
CLASS 3.— HALOIDS AND SALTS.
Group 1. — Ammonia. Group 6. — (Cont.)
Group 2.— Potash. Scheelite.
Group 3. — Soda. Fluor.
Halite. Group 7. — Magnesia.
Group 4. — Baryta. Magnesite
Barytes. Group 8. — Alumina*
Group 5. — Strontia. Kalinite.
Celestite. Wavellite
Group 6. — Lime* Tavistockite
Calcite. Childrenite
Aragonite. Group 8. — Ceria.
Dolomite. Churchite
Apatite. Group $.—Zirconia.
Gypsum. Group 16. — Yttria.
CLASS 4. — EARTHS.
(Silica, Alumina, and Magnesia, with their hydrates.)
Group 1. — Silica. Group 2. —A lumina.
Quartz Group 3. — Magnesia.
Jasper
Calcedony
Opal
CLASS 5.— SILICATES AND ALUMINATES.
The groups here are mostly chemical, the Felspars, Zeolites, and Garnets being
made into distinct groups.
DIVISION II.-METALLIC MINERALS.
CLASS 1.— MINERALS CONTAINING METALS THAT ARE BRITTLE AND
FUSIBLE ONLY WITH DIFFICULTY.
Group 1. — Titanium. Group 8. — Uranium.
Anatase Zippaeite
Rutile Pitchblende
Brookite Johannite
Ilmenite Autunite
Titanite Torbernite
Group 2. — Tantalum. Group 9. — Manganese.
Group 3,— Niobium and Pelopium. Psilomelane
Group 4. — Tungsten. "Wad
Wolframite Pyrolusite
Scheelite Manganite
"Wolfram Braunite
Group 5. — Molybdenum. Diallogite
Molybdenite Rhodonite
Group 6. — Vanadium.
Group 7.— Chromium.
Chromite
42 CHAPTER IV.— SYSTEMATIC.
CLASS 2.— MINERALS CONTAINING METALS THAT ARE BRITTLE, EASILY
FUSIBLE, AND VOLATILE.
Group 1. —A rsenic. Group 2. —f Cont. )
Arsenic Ceryantite
Arsenolite Antimonite
Leucopyrite Jamesonite
Condurrite Group 3.— Tellurium.
Smaltite Group 4.— Bismuth.
Group 2.— Antimony. Bismuth
Antimony Bismite
Senarmontite Bismuthinite
Valentinite Wittichenite
Stibiconite
CLASS 3.— MINERALS CONTAINING METALS THAT ARE MALLEABLE ; NOT
EEDUCIBLE BY HEAT ALONE.
Group I.— Zinc. Group 6.— Cobalt.
Calamine Asbolane
Blende Cobaltite
Goslarite Smaltite
Group 2.— Cadmium. Erythrite
Group 3.— Tin. Group 7. — Nickel.
Cassiterite Annabergite
Stannite Millerite
Group 4. — Lead. Niccolite
Plumbic Ochre Pentlandite
Cerussite Group 8. — Copper.
Galena Copper
Anglesite Cuprite
Cromfordite Melaconite
Pyromorphite Malachite
Mimetite Chessylite
Bleinierite Lunnite
Jamesonite Libethenite
Bournonite Chalcocite
Linarite Covellite
Group 5. — Iron. Erubescite
Magnetite Chalcopyrite
Hematite f ahlerz
Goethite Tennantite
Limonite Bournonite
Chalybite Brochantite
Vivianite Cyanosite
Pyrrhotite Atacamite
Pyrites ChrysocpUa
Marcasite Torbernite
Mispickel Condurrite
Leucopyrite Cornwallite
Melanterite Clinoclase
Cronstedtite Olivenite
Chloropal Liroconite
Pharmacosiderite Chalcophyllite
Scorodite
Pitticite
CLASS 4. — MINERALS CONTAINING NOBLE METALS ; REDUCIBLE BY
HEAT ALONE.
Group 1. — Mercury. Group 3. — Gold. — Gold
>Group 2. — Silver. Group 4. — Platinum.
Silver Group 5. — Palladium.
Kerate Group 6. — Rhodium.
Argentine Group 7. — Iridium.
Stephanite Group 8. — Osmium.
Polybasite Group 9. — Lanthanium.
Pyrargyrite Group 10. — Columbium.
CHAPTER IV.— SYSTEMATIC. 43
III.— MIXED.
(System of Weiss and Nicol.)
ORDER I. — OXIDISED STONES.
Fam. 1. —Quartz. Fam. !.—( Cont. )
Quartz Pyroxene
Jasper Hypersthene
Calcedony Khodonite
Opal Babingtonite
Fam. "2. — Felspar* Isopyre
Orthoclase Fam. 8.— Clay.
Albite Kaolin *
Fam. 3. — Scapolite. Smectite
Prehnite Allophane
Fam. 4.— Haloid Stones, Schrotterite
Wavellite Agalmatolite
Fam. 5.- Zeolite. Steatite
Natrolite Fam. 9. — Garnet.
Stilbite Garnet
Analcite Epidote
Fam. 6. — Mica. Axinite
Muscovite Andalusite
Lepidolite Staurolite
Lepidomelane Fam. 10. — Gems.
Chlorite Topaz
Talc Beryl
Schiller-spar Tourmaline
Serpentine Chondrodite
Cronstedtite Fam. 11.— Metallic Stones.
Fam. 7. — Hornblende. Chloropal
Amphibole
ORDER 2.— SALINE STONES.
Fam. l.—Calc Spar. Fam. 3.— (Cont.)
Calcite Celestite
Aragonite Fam. 4. — Gypsum.
Dolomite Gypsum
Magnesite Fam. 5.— Rock Salt.
Fam. 2. - Fluor Spar. Halite
Fluor Kalinite
Fluellite Melanterite
Apatite Goslarite
Childrenite Cyanosite
Fam. 3. — Heavy Spar. Johannite
Barytes
ORDER 3.— SALINE ORES.
Fam. 1. — Sparry Iron Ores. Fam. 2. — (Cont.)
Chalybite Brochantite
Diallogite Langite
Calamine Vivianite
Pitticite Torbernite
Fam. 2. — Copper Salts. Autunite
Chrysocolla Erythrite
Chessylite Annabergite
Malachite Fam. 3.— Lead Salts,
Chalcophyllite Cerussite
Erinite Anglesite
Liroconite Linarite
Olivenite Cromfordite
Clinoclase Pyromprphite
Lunnite Mimetite
Libethenite Bleinierite
Atacamite Kerate
Pharmacosiderite Scheelite
Scorodite
44
CHAPTER IV.— SYSTEMATIC.
ORDER 4.— OXIDISED ORES.
Fam. 1. — Oxidised Iron Ores.
Magnetite
Chromite
Ilmenite
Hematite
Limonite
Goethite
Fam. 2.— Tin Ore.
Cassiterite
Wolfram
Titanite
Brookite
Anatase
Kutile
Pitchblende
Fam. 3. — Manganese Ores.
Pyrolusite
ORDER 5.-
Fam. S.-(Cont.)
Manganite
Braunite
Psilomelane
Wad
Asbolane
Bismite
Wolframite
Zippaeite
Plumbic Ochre
Fam. 4.— Red Copper Ores.
Cuprite
Fam. 5.— While Antimony Ores.
Valentin ite
Senarmontite
Arsenolite
NATIVE METALS.
Fam. 1. Fam. \.—(Cont.)
Gold , Bismuth
Silver Antimony
Copper Arsenic
ORDER 6.— SULPHURETTED METALS.
Fam. I.— Pyrites.
Pyrites
Marcasite
Pyrrhotite
Leucopyrite
Mispickel
Cobaltite
Smaltite
Niccolite
Millerite
Pentlandite
Chalcopyrite
Erubescite
Condurrite
Fam. 2.— Lead Glance,
Galena
Argentite
Chalcocite
Covellite
Molybdenite
Fam. 1. — Sulphur.
Sulphur
Fam. 2.— Diamond,
Fam. 3.— Coals.
Graphite
Anthracite
Fam. 3. — Grey Antimony Ore.
Antimonite
Jamesonite
Berthierite
Bismuthinite
Fam, 4. — Grey Copper Ore.
Fahlerz
Tennantite
Bournonite
Stephanite
Polybasite
Stannite
Wittichenite
Fam. 5.— Blende.
Blende
Fam. Q.—Ruby Blende.
Pyrargyrite
ORDER 7.— INFLAMMABLE.
Fam. 3.—(Cont.)
Lignite
Fam. 4. — Mineral Resins.
Bitumen
Retinite
IV.— ARRANGEMENT ACCORDING TO CRYSTALLINE FORM.
Analcite
Argentite
Arsenolite
Bismite (?)
Blende
Chromite
Cobaltit*
Copper
Cuprite
Erubescite
Fahlerz
Fluor
Galena
Garnet
1.— CUBIC.
Gold
Halite
Kalinite
Kerate
Magnetite
Pentlandite
Pyrites
Senarmontite
Silver
Smaltite
Stannite (?)
Tennantite
Pharmacosiderite Wolframite (?)
CHAPTER IV.— SYSTEMATIC.
45
2. — PYRAMIDAL.
Anatase
Chalcopyrite Scapolite
Rutile
Braunite
Cromfordite Scheelite
Torbernite
Cassiterite
3.— RHOMBIC.
Andalusite
Anglesite
Cerussite Lepidomelane
Cervantite Libethenite
Pyrolusite
Scorodite
Antimonite
Chalcocite Liroconite (?)
Stephanite
Aragonite
Childrenite Lunnite (?)
Staurolite
Atacamite
Chondrodite Manganite
Stilbite
Autunite
Erinite (?) Marcasite
Sulphur
Barytes
Berth ierite
Fluellite Mispickel
Gilbertite Natrolite
Tavistockite (?)
Topaz
Bismuthinite
Goethite Olivenite
Valentinite
Bournonite
Goslarite Pinite
Wavellite
Brochantite
Jamesonite Polybasite (?)
Wittichenite
Brookite
Langite Porcellanite (?)
Wolfram
Celestite
Lepidolite Prehnite
4.— OBLIQUE.
Amphibole
Clinoclase Johannite
Pyroxene
Annabergite
Epidote Linarite
Rhodonite
Beraunite
Erythrite Malachite
Schiller Spar
Chessylite
Gypsum Melanterite
Titanite
Churchite
Hypersthene Orfchoclase
Vivianite
5. — ANORTHIC.
Albite
Axrnite
Babingtonite Mesolite?
Cyanosite
Saussurite ?
6.— HEXAGONAL.
Antimony
Chalybite Hematite
Niccolite
Apatite
Chlorite Ilmenite
Pyrargyrite
Arsenic
Beryl
Connellite Magnesite
Covellite Millerite
Pyromorphite
Pyrrhotite
Bismuth
Cronstedtite Mimetite
Quartz
Calamine
Diallogite Molybdenite
Talc
Calcite
Dolomite Muscovite (?)
Tourmaline
Chalcophyllite
Graphite
7. -AMORPHOUS.
Agalmatolite
Chloropal Kaolin
Retinite
Agnesite
Chrysocolla Limonite
Schrotterite
Allophane
Cornwallite Melaconite
Serpentine
Asbolane
Demidoffite Opal
Smectite
Bayldonite
Domeykite Pigotite
Steatite
Bitumen
Glauconite Pitchblende
Stibiconite
Bleinierite
Hisingerite Pitticite
Wad
Calcedony
Isopyre Plumbic Ochre
Zippseite
Chenevixite
Jasper Psilomelane
CHAPTER V.
DISTRIBUTIVE.
Of the large number of minerals which have been found in the district
treated of in this Handbook, some, as the various forms of Quartz, occur almost
everywhere ; others, such as Pyrites, are found wherever mining is carried on ;
others, again, occur only in small quantities or are limited to certain areas.
Thus, ores of Iron, chiefly Hematite or Limonite, are to be found in the parish
and neighbourhood of St. Just, in the parishes of Constantine, Ladock,
46
CHAPTER V.—DISTBIBUTIVE.
and Perranzabuloe, at Huel Ruby, Retire, and Restormel ; at Ilsington, Brixham,
and other places, while small quantities of the same, and closely related
minerals, are to be met with in most mines.
Manganese ores are by no means so widely distributed, for they are almost
entirely unknown in the West of Cornwall, although found in abundance near
Launceston, near Tavistock, Brent Tor. at Upton Pyne, and many other places
ill Devonshire.
Among the rarer " metallic minerals " several of the arseniates of copper
have only been noticed in Gwennap. Ilmenite or Titaniferous Iron Ore
is only to be found in or near St. Keverne ; Anatase and Brookite occur in very
small quantities only at Virtuous Lady Mine, near Tavistock, Delabole,
Tintagel, and in a quarry near St. Austell. The distinguishing material of these
minerals, however, Titanic Acid, is very widely distributed through our
Cornish rocks, as shewn by Mr. J. A. Phillips's recent analyses, so that
additional localities for them may perhaps occur ere long. Chromite
has been found in small quantity, but only in the Lizard district. Among
the "non-metallic" minerals, Garnet only occurs near a junction of
granite and greenstone, the localities being tolerably numerous, although the
mineral is never abundant. Topaz occurs only in granite, but in localities as
widely separated as St. Michael's Mount and Lundy Island. Beryl has been
found in some of the same localities, but is still more rare. Barytes has
occurred only at one locality west of Truro, viz., at the Gwennap Mines, with
copper ores. It has also occurred in tolerable quantity at Herodsfoot, at Huel
Mary Ann, with lead ores, and at Babbicombe Bay, and other localities in
Devon, with Calcite.
The Zeolites are found only at St. Just, in a narrow strip of greenstone,
which forms the precipitous coast, and at Stenna Gwynn, and very sparingly
even in these localities. Wavellite has only been certainly found near Barn-
staple, although found there 87 years ago.
Graphite has occurred in small nodules in elvan courses at Kerjiliack,
near Penryn ; at Tuckingmill ; near Grampound ; and at Bpscastle. Retinite has
occurred only in the Lignites of Bovey Tracey ; Mineral Pitch only in the copper
mines in Gwennap, Illogan, and neighbouring parishes, and perhaps at
Chudleigh, in Devon.
A list of mines and mineralogical localities in the two counties, with the
minerals which have been noticed, is given below. The more common minerals
are only mentioned when particularly fine, or remarkable for their situation.
Of the rarer minerals every locality known to the author has been set down.
Mines at work in January, 1871, are indicated by small capitals, and the
material chiefly raised is indicated in a separate column. "When a mineral is
very characteristic of a given locality, or occurs in a very fine condition, its
name is printed in small capitals.
LIST OF MINES AND MINERALOGICAL LOCALITIES,
TOPOGRAPHICALLY ARRANGED.
CORNWALL.— HUNDRED OF PEN WITH.
(West Division.}
Parish. Locality.
PrMme8°f ! More remarkable Minerals.
Scilly.
Sennen.
Do.
St. Levan.
Land's End.
Nangisel Cov.e.
Tol Pedn Pen-
with.
—
Flints on the beaches and high
lands (DelaBeche, Rep. Dev.
Corn.) Schorl occasionally in
the granite, sometimes replacing
Mica (Statham, Geologist, voL
II., p. 23.
Schorl, fractured flints in elevated
positions.
Amethyst, Pinite ; occasionally
fine crystals of Orthoclase in
the Granite.
Pinite.
CHAPTER V.— DISTRIBUTIVE.
47
LIST OP MINES, &c.— CORNWALL, PENWITH, West Division (Cont.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals
St. Burian.
Boscawen Cliffs.
_
Axinite, Rock Crystal.
Do.
Penberth.
—
WOOD-TIN.
Do.
Lamorna Cove.
—
Axinite, Epidote, Pinite, Topaz.
Do.
Rose-moddress.
—
Garnet.
Do.
Cam Silver.
—
Epidote.
St. Just.
BALLESWIDDEN
Tin.
Bismuthinite, Bismuth, Litho-
marge; fine crystals of Ortho-
clase, and Mica in the Granite.
Do.
Bellon, Huel.
Amethyst, Mica.
Do.
BOSCASWELL or
Tin and
Calcedony, Cassiterite.
BOSCASWELL
Copper.
DOWNS.
Do.
BOSCEAN.
Tin.
Fine imbedded crystals of red-
Boscreagen.
dish-brown and white Ortho-
clase.
Do.
BOSOKN.
Tin.
Occasionally fine crystals of Cas-
siterite.
Do.
Boshase Moor.
Stream Tin.
Do.
BOSWEDDAN and
Tin.
Beryl (Huel Castle).
HUEL CASTLE.
Do.
BOTALLACK and
Tin and
Actinolite, Amethyst, Apatite,
CARN YOUTH,
Copper.
Aragonite, Atacamite, Augite,
with HUEL COCK
Axinite, Bismuth, Bismuthinite
and the Cliffs to
BOTALLACKITE, Calcite, Chal-
the north.
cocite, Cobaltite, Cyanosite, Di-
allogite, Dolomite, Epidote, Ery-
thrite, Fahlerz? Fluor, Garnet,
Goethite, Goslarite, Jasper, Ke-
rate, Magnetite, Malachite, Man-
ganite, Mesolite, Mispickel, Na-
trolite, Opal, Pitchblende, Phar-
macosiderite, Prehnite, Pyrrho-
tite, Silver, Smaltite, (Steatite,
Stannite, Stilbite, Tallingite,
Tourmaline, Tremolite, Vivian-
ite, &c.
Do.
Cape Cornwall.
—
Schorl, Hornblende, Actinolite.
Do.
CAPE CORNWALL
Tin.
Dolomite, Garnet, Jasper.
MINE.
Do.
Carne, Huel.
Axinite, ISOPYRE, Prehnite, Na-
trolite, Stilbite.
Do.
Carn Bosavern.
—
LEPIDOMELANE.
Do.
Do.
Chycornish Carn.
Crowns Rock.
• —
Garnet.
GARNET, MAGNETITE, Actinolite,
APATITE, AXINITE, Epidote, Na-
trolite, Prehnite, &c.
Do.
Cunning, Huel.
Mica, Cassiterite.
Do.
Diamond, Huel.
ROCK CRYSTAL.
Do.
LEVANT.
Tin and
Amethyst, Aragonite, Bismuth,
Copper.
Bismite, Chalcocite, Dolomite,
Fahlerz? Hornblende, Kerate,
Pharmacosiderite, SILVER.
Do.
LEVANT, NORTH.
Tin.
Cassiterite.
Do.
Little Bounds.
Chlorite, Schorl.
48
CHAPTER V.— DISTRIBUTIVE.
LIST OF MINES, &c.— CORNWALL, PENWITH, West Division (Cont. )
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
St. Just (CW.)
OWLES, HUEL &
Tin.
Actinolite, Apatite, Calcite, Cha-
Huel Edward.
lybite, Diallogite, Pharmacosi-
derite (Huel Owles); Aragonite,
Autunite, Chrysocolla, Mala-
chite, Pitchblende, Torbernite,
VIVIANITE, Zippaeite (Huel Ed-
ward).
Do.
Pendeen Consols
Tin and
Cassiterite.
Copper.
Do.
Pendeen Cove
—
Steatite, in small veins in slate.
(south of).
Do.
Parknoweth.
—
Cassiterite, Chlorite, Schorl, Vi-
vianite.
Do.
Roscommon Cliff
—
Asbolane, Axinite, Erythrite, Se-
lenite, Tourmaline.
Do.
SPEARNE CON-
Tin.
SOLS.
Do.
SPEARN MOOR.
Tin and
Fluor, Rock Crystal.
Copper.
Do.
Stennack, Huel.
Jasper.
Do.
St. JUST AMAL-
Tin.
Cassiterite.
GAMATED.
Do.
Tregarva Moor.
—
Cassiterite, Gold (in ancient
stream works).
Do.
Trewellard Cliff.
—
Axinite, Pinite, Rock Crystal.
Sancreed.
Mulvra Hill.
—
Pinite ; fine crystals of Orthoclase
Paul.
Wherry Mine.
Tin.
Cassiterite, Cobaltite.
Morvah.
Garden Mine.
Tin.
Do.
Morvah United.
Chlorite, Felspar, Fluor, Hema-
tite, Mica, Schorl.
Madron.
Chalybite, Sphserosiderite.
Gulval.
DING DONG.
Tin.
Chlorite, Fluor, Jasper, Chalco-
cite, Schorl.
Ludgvan.
Vorlas.
Flint.
Do.
Darlington, Huel
Mispickel, Pyrites, Schorl, Cas-
siterite.
Do.
Darlington, West
Huel.
Argentite, Galena (argentiferous),
NATIVE SILVER.
Zennor.
CARNELLOW.
Copper and
Tin.
Occasional fine crystals of Cassi-
terite.
Towednack.
GIEW CONSOLS.
Tin.
Cassiterite, Schorl.
Do.
Union, Huel.
Cassiterite, Chlorite, Mica,
Schorl.
CORNWALL, PENWITH, East Division.
Parish.
Localities.
Produce of
Mines.
More remarkable Minerals.
Lelant.
Do.
Do.
Do.
Consolidated Ms.
KITTY, HUEL.
MARGARET, HUEL
MARGARET, WEST
HUEL.
Tin.
Tin.
Tin.
Cassiterite, Felspar, Mica, Schorl.
Cassiterite, Mica.
Cassiterite.
Cassiterite.
CHAPTER V.— DISTRIBUTIVE.
49
LIST OF MINES, &c.— CORNWALL, PENWITH, East Division (Cont.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Lelant ( Cont. )
MARY, HUEL.
Tin.
Blende, Calamine, Chlorite, Mis-
pickel, Molybdenite.
Do.
Poldice, West.
Actinolite, Cassiterite, Horn-
blende.
Do.
PROVIDENCE,
Tin.
EAST.
Do.
PROVIDENCE
Tin and
Calcedony, Cassiterite, CHALCO-
MINES.
Copper.
CITE, Chalcotrichite, Chlorite,
Clinoclase, Copper, Connellite,
Liroconite, Mispickel, Pitch-
blende, Pyrites, SCHORL, Tor-
bernite.
Do.
Ditto (Including
Cassiterite, Chalcocite, Chessy-
Huel Speed.)
lite, Cuprite, Felspar, Mala-
chite, Melaconite, Pyrites,
Schorl. (Huel Speed.}
Do.
PROVIDENCE,
Tin.
SOUTH
Do.
Reeth, Huel.
Cassiterite, Chalcocite, Chlorite,
Felspar, Mica, Schorl.
Do.
TREVARRACK UTD
Tin.
Cassiterite, Schorl.
St. Ives.
Balnoon.
Cassiterite, Felspar, Mica, Schorl.
Do.
FANNY ADELA
Tin.
Cassiterite.
(Hawke's Point).
Do.
Mellanoweth.
Anglesite.
Do.
PENCROM, HUEL.
Tin.
Cassiterite.
Do,
EOSEWALL HILL
Tin.
Cassiterite.
and RANSOM
UNITED.
Do.
ST. IVES CONSO-
Tin and
Actinolite, BISMUTH, Cassiterite,
LIDATED.
Copper.
CHALCOClTE(very fine,recently),
Chalcopyrite, Chalcotrichite,
Chlorite, Cyanosite, Felspar,
Fluor, Hematite, Isopyre ?
Limonite, Mica, Schorl.
Do.
ST. IVES, WEST.
Tin.
Cassiterite.
Do.
TRELYON CONSLS.
Tin and
Cassiterite.
(Huel Venture.)
Copper.
Do.
Trenwith, Huel.
Chalcocite, Cuprite, Erythrite,
Hematite, Hornblende, Mela-
conite, Pitchblende, Torbernite.
Do.
St. Michael's Mt.
Apatite, Beryl, Cassiterite, Fluor,
Garnet, Orthoclase, Lepidolite,
Pinite, Rock Crystal, Stannite,
TOPAZ, Tourmaline, Wolfram,
Zippseite.
St. Hilary.
GREAT WESTERN
Tin and
Cassiterite.
MINES.
Copper.
Do.
Prosper, Huel
MFLANTERITE.
Do.
Marazion Mines.
Blende, Chalcopyrite, Felspar,
Hornblende, Limonite, Melaco-
nite, Pyrites, Tourmaline.
Do.
Cuddan Point.
—
ACTINOLITE.
Perranuthnoe.
The Grebe.
Actinolite.
Do.
Mount Mine?
Argentite.
St. Erth.
Bell, Huel.
Anglesite, Pyromorphite.
50
CHAPTER V.— DISTEIBUTIYE.
LIST OF MINES, &c.— CORNWALL, PENWITH, East Division (Cont.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
St.Erth(CW.)
Elizabeth, Huel.
Blende, Chalcopyrite, Chlorite,
Galena, Melaconite, Pyrites.
Do.
Gilbert, Huel.
Cassiterite.
Do.
Godolphin, West.
Actinolite, Blende, Chalcocite,
Galena, Malachite, Melaconite.
Do.
TEEVEN.
Tin.
Do.
MELLANEAB.
Copper.
Chalcopyrite.
Phillack.
Alfred, Huel.
Bayldonite? Calcite, Cerussite,
Calcedony, Chalcocite, Chalco-
pyrite, Erubescite, Kerate, Ma-
lachite, Mimetite, PYBOMOE-
PHITE (the finest ever found in
Cornwall), Rock Crystal, Silver.
Do.
Ann, Huel?
Argentite, Kerate.
Do.
Kayle, Huel.
Chlorite, Chalcopyrite, Galena,
Melaconite.
Do.
Boiling Well.
Galena.
Gwithian.
Silver Valley.
Kerate, Silver.
Gwinear.
Carsize Consols.
Blende, Cassiterite, Chalcopyrite,
Mispickel.
Do.
Duffield Mine.
Chalcocite, Chalcopyrite, Limo-
nite, Melaconite, Pyrites.
Do.
Gwinear, Huel.
Cassiterite, Molybdenite.
Do.
Herland, Huel.
AEGENTITE, Bismite, Bismuth,
Bismuthinite, Cassiterite, Chal-
copyrite, KEEATE, Limonite,
Melaconite, Mispickel, Pyrargy-
rite, Rock Crystal, Silver, Smal-
tite, Wolfram.
Do.
Providence, Huel.
Cassiterite, Chalcocite, Chalco-
pyrite, Melaconite.
Do.
Prince Geo. Mine.
Chrysocolla, Malachite.
Do.
Relistian.
Cassiterite, Chalcocite, Chalco-
Do.
Kelistian, East.
pyrite, Melaconite, Pyrites.
Chlorite, Tennantite.
Do.
Rosewarne.
Tin & Cop.
Cassiterite, Chalcopyrite, Opal.
Do.
ROSEWAENE, CNLS
Tin & Cop.
Cassiterite.
Do.
ROSEWAENE, EST.
Tin & Cop.
Cassiterite.
Do.
Rosewarne, New.
Cassiterite, Chlorite, Dolomite,
Jasper, Semi-Opal.
Do.
ROSEWAENE UTD.
Copper.
Chalcopyrite.
Do.
Tremayne, Huel.
Cassiterite, Silver.
Do.
Trevascus, Huel.
Actinolite, Axinite, Bitumen,
Blende, Calcedony, Chalybite,
Dolomite, Fahlerz, Fluor,
Galena, Mispickel, Tennantite.
Do.
Unity, Huel.
Copper
and Tin.
Actinelite, Amethyst, Asbolane,
Bitumen, Blende, Cassiterite,
Chalcopyrite, Chalcophyllite,
Chessylite, Chlorite, Chryso-
colla, Clinoclase, Connellite,
Copper, Cuprite, Erythrite,
Fluor, Galena, Jasper, Liroco-
nite, Malachite, Marcasite, Mi-
metite, Mispickel, Molybdenite,
Olivenite, Petroleum, Pharma-
cosiderite, Pyrites, Scorodite,
Tennantite, Torbernite.
CHAPTER V.-— DISTRIBUTIVE.
51
LIST OF MINES, &c.— CORNWALL, PENWITH, East Division (Cont. )
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Crowan.
CKENVER and
Tin and
Cassiterite, Chalcocite, Chalco-
HUEL ABRAHAM
Copper.
pyrite.
Do.
MILLET, HUEL.
Copper.
Chalcopyrite.
Do.
Strawberry, Huel
Blende, Chalcopyrite, Melaco-
nite, Pyrites.
Camborne.
CAMBORNE VEAN
Tin and
Axinite, Chalcocite, Erubescite,
Copper.
Fluor, Hornblende.
Do.
CARN CAMBORNE.
Mispickel.
Do.
CONDURROW,
Tin and
Cassiterite.
SOUTH.
Copper.
Do.
Crofty, Huel.
Blende, Galena, Hornblende.
Do.
DOLCOATH.
Tin and
Amethyst, Argentite, Arsenic ?
Copper.
BISMUTH, Bismuthinite,Blende,
CASSITERITE, Chalybite, Chalco-
cite, Chalcopyrite, Chlorite,
Copper, Cobaltite, Cuprite,
Dolomite, Erubescite, Eryth-
rite, Fluor, Galena, Hematite,
Hornblende, Kerate, Langite,
Limonite, LITHOMARGE, Mala-
chite, Melaconite, Mispickel,
Orthoelase, Pitticite, Pitch-
blende, Pyrargyrite, Pyrites,
ROCK CRYSTAL, Schorl, Silver,
Smaltite, Tennantite, Wolfram.
Do.
Dolcoath, North.
Kerate, Silver.
Do.
GRENVILLE, EAST
Copper.
Chalcopyrite.
Do.
GREN VILLE, HUEL
Copper.
Chalcopyrite.
Do.
PENDARVESUTD.
Tin.
Condurrite, Copper, Cassiterite,
Fahlerz.
Do.
ROSKEAR, NRTH.
Tin and
Actinolite, Blende, Chalcopyrite,
Copper.
Chlorite, Dolomite, Galena,
Haytorite, Jasper, Opal, Prase,
Rock Crystal.
Do.
SETON, HUEL.
Copper.
Chalcopyrite.
Do.
STRAY PARK.
Copper
Cassiterite.
and Tin.
Illogan.
AGAR, HUEL.
Copper.
Chalcopyrite.
Do.
BASSET, HUEL.
Copper.
Argentite, Autunite, Chalcocite,
Chalcopyrite, Copper, Cuprite,
Galena, Malachite, Silver.
Do.
BASSET, WEST.
Copper
and Tin.
Chalcopyrite, Cuprite.
Do.
Basset, South.
Argentite, Autunite, Chessylite,
Chalcocite, Copper, Fahlerz,
Malachite, Rock Crystal, Jo-
hannite ?
Do.
CARN BREA.
Copper
and Tin.
Agate, Cassiterite, Chalybite,
Chalcocite, Chlorite, Coudur-
rite, Copper, Covellite, Cuprite,
Erubescite, Fluor, Goethite,
Hematite, Limonite, Mica,
Marcasite, Mispickel, Pharma-
cosiderite, Pyrites, Rock Crys-
tal, Stannite, Tennantite, Wol-
fram, Smectite?
52
CHAPTER V.— DISTRIBUTIVE.
LIST OF MINES, &c.— CORNWALL, PENWITH, East Division (Cont.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Illogan (Gont.)
CAEN BBEA, STH.
Tin and
Chalcopyrite, Cassiterite.
Copper.
,
Do.
COOK'S KITCHEN.
Tin and
Bitumen, Chalcocite, Chlorite,
Copper.
Erubescite, Fahlerz, LITHO-
MARGE, LONCHIDITE, Marcasite,
Mispickel, Pyrites, Schorl, Stea-
tite? Tennantite.
Do.
CROFTY, NORTH
Copper
Chalcopyrite.
HUEL.
and Tin.
Do.
Crofty,EastHuel
Actinolite, Axinite, Bitumen,
Blende, Rock Crystal.
Do.
CROFTY, SOUTH
Tin and
Chalybite, Stannite.
HUEL.
Copper.
Do.
DOLCOATH (STH.)
Copper.
Chalcopyrite.
& CARNARTHEN
CONSOLS.
Do.
Druid, Huel.
Chondrodite? Condurrite, Goe-
thite, Lithomarge, Limonite.
Do.
EMILY HENRIET-
Copper.
Chalcopyrite.
TA, HUEL.
Do.
FRANCES, SOUTH
Copper.
Chalcopyrite, Chalcotrichite,
HUEL.
Cuprite, Cyanosite, Libethe-
nite, Lithomarge.
Do.
FRANCES, WEST
Copper.
Chalcopyrite, Cuprite.
HUEL.
Do.
Garth Mine.
Cassiterite, WOOD TIN.
Do.
POOL, EAST.
Copper, Tin,
& Wolfram.
Amethyst, Blende, CALCEDONY,
CHALCOPYRITE, Chalcocite, Cha-
lybite, CHLOROPHANE, Copper,
Cuprite, Erythrite, Felspar, Ga-
lena, Leu copy rite, Langite, Ma-
lachite, Silver ? Smaltite, ROCK
CRYSTAL, WOLFRAM.
Do.
Pool, North.
Copper.
Calcedony, Chalcopyrite.
Do.
SETON, EAST
Copper.
Chalcopyrite, Pyrites.
HUEL.
Do.
TINCROFT.
Tin and
Cassiterite, Chalcocite, Chalco-
Copper.
pyrite, Chalybite, Chlorite, Cu-
prite, Erubescite, Goethite, He-
matite, Limonite, Lithomarge,
Melaconite, Mispiekel, Oliven-
ite, Pitchblende, Pyrites, Ten-
nantite, Torbernite.
Redruth.
BASSET, EAST
Copper.
Chalcopyrite.
HUEL.
Do.
Beauchamp,Huel
Chalybite, Goethite, Chalcocite.
Do.
BULLER, HUEL.
Copper
Amethyst, Calcite, Cassiterite,
and Tin.
Chalcocite, Chalcopyrite, Cha-
lybite, Chessylite, Copper, CU-
PRITE, Fluor, Malachite, Melaco-
nite, Olivenite, Opal, Pitch-
blende, Rock Crystal, Torber-
nite, Zippseite.
Do.
Cardrew Downs.
—
Chlorite, Fluor, Limonite, Mela-
conite.
Do.
CARNBREA,EAST
Copper.
Chalcopyrite.
CHAPTER V.— DISTEIBUTIVE.
53
LIST OF MINES, &c.— COKNWALL, PENWITH, East Division (Cont.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Redruih(Cont)
Do.
Clyjah Mine.
COPPEK HILL.
Copper.
Epidote, Garnet, Zippseite.
Chalcocite, Chalcopy rite, LANGITE
Do.
Cupid, Huel.
Fluor.
Do.
Downs, Great
Copper.
Chalcopyrite.
North.
Do.
Downs, North.
Copper.
Blende, Cassiterite, Chalcopy-
rite, Fluor, Limonite, Mime-
tite? Pyrites.
Do.
Elizabeth, Huel.
Smaltite.
Do.
Fanny, Huel.
Chalcocite, Wolfram.
Do.
HARMONY AND
Magnetite, Wolfram.
MONTAGUE.
Do.
PEDN-AN-DEEA.
Tin and
Copper.
AMETHYST, CALCEDONY, Cas-
siterite, Chlorophane, Chlorite,
Clinoclase, Fluor, Galena, Oli-
venite, PHARMACOSIDERITE,
Psilomelane ? Pitchblende,
Scorodite, Smaltite, Wad ?
Wolfram, Zippseite.
Do.
Scorrier Consols.
Kock Crystal, Stannite.
Do.
SPARNON, HUEL.
Tin and
Agate, Arsenolite, Bismuth,
Copper.
Bismuthinite, Cobaltite, Ery-
thrite, Fluor, Gold, Millerite,
Eock Crystal, SMALTITE.
Do.
Do.
TOLGUS, WEST.
TOLGUS, GREAT
Copper.
Copper.
Chalcopyrite.
Chalybite, Erubescite, Mispickel,
SOUTH.
Wad.
Do.
TOWAN, SOUTH.
Copper.
BITUMEN, Chalcopyrite.
Do.
Trefusis, Huel.
Chessylite, Chrysocolla, Mala-
chite, Melaconite.
Do.
Treleigh, Consls.
Copper.
Chalcopyrite.
Do.
TRELEIGH, NEW.
Copper.
Do.
Treskerby, Nrth.
Copper
and Tin.
Bitumen, Chalcopyrite, Copper,
Cuprite, Petroleum?
Do.
UNY, HUEL.
Tin and
Blende, Cassiterite.
Copper.
CORNWALL, KIRRIER, West Division.
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Landewed-
nack.
Kynance Cove.
—
Agate, Asbestos, Calcite, Dial-
lage, Hornblende, Orthoclase,
Saussurite? Serpentine, STEA-
TITE, Talc.
Do.
Lizard Head.
Calcite, Hornblende, Orthoclase,
Talc, Magnetite.
Kuan Major.
Everywhere.
—
SERPENTINE.
Ruan Minor.
Cadgwith.
—
Actinolite, Asbestos, Calcite,
Chromite, DIALLAGE, Horn-
blende, SERPENTINE, PYRITES.
Do.
Caerleon Cove.
—
Orthoclase, in granite veins.
Do.
Kildown.
—
Schiller Spar.
Do.
Kennack Cove.
—
Schiller Spar.
54
CHAPTER V.— DI8TEIBUTIYE.
LIST OF MINES, &c.— CORNWALL, KIRRIER, West Division (Cont.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Grade.
Goonhilly Downs
Asbestos, Calcedony, Hornblende
Serpentine.
Do.
The Balk.
—
Orthoclase and Mica in granite
veins.
Mullion.
Gue Graze.
—
STEATITE.
Do.
Ghost Croft.
—
Copper.
Do.
Mullion Island.
—
SERPENTINE.
Do.
Polurian Cove.
—
Chrysocolla, Copper, Cuprite,
Hornblende, Malachite, Pyrites,
Do.
Pradanack.
Serpentine, Steatite.
Hornblende.
Do.
Do.
Unity, Huel.
Vellan Head.
Chrysocolla, Copper, Cuprite.
Orthoclase, &c., in granite veins.
St. Keverne.
Black Head.
—
Diallage, Serpentine, Steatite.
Do.
Coverack Cove.
—
DIALLAGE, Hornblende, Ortho-
clase, SERPENTINE, Steatite.
Do.
Crousa Downs.
—
Diallage, in Diallage rock.
Do.
Downas, Huel.
Chalcocite, Copper.
Do.
Gwendra.
—
Menaccanite, disseminated.
Do.
Gwinter.
—
Magnetite, disseminated in Dial-
lage rock ; Saussurite?
Do.
Karak-clews.
—
DIALLAGE.
Do.
Lanarth.
—
Manaccanite.
Do.
Manacle Point.
—
Serpentine, Steatite.
Do.
Pednboar Point.
—
Hornblende.
Do.
Polkerris Point.
—
Hornblende, Serpentine.
Do..
Porthalla.
—
Hornblende, ILMENITE, Limonite.
Do.
Treglossack.
—
Calcite.
Manaccan.
In the bed of a
—
MANACCANITE.
stream.
Mawgan.
Trelowarren.
Serpentine, Steatite.
Do.
Breage.
Anson, Huel.
FORTUNE, GREAT
Copper.
Tin and
Chalcopyrite, Pyrites.
Cassiterite, Chalcocite, Chalco-
HUEL.
Copper.
pyrite, Erubescite, Melaconite,
Mica, Orthoclase, Pyrites, Wol-
fram.
Do.
FORTUNE, SOUTH,
Copper.
Chalcopyrite, Cassiterite.
HUEL.
Do.
Do.
Godolphin Bridge
GREAT WORK,
Copper.
Tin and
Cassiterite, Chlorite, Dolomite.
WEST.
Copper.
Do.
LEEDS MINE.
Tin.
Cassiterite.
Do.
NEW HENDRA.
Tin.
Cassiterite.
Do.
Pengelly Croft
Tin.
Cassiterite, Scheelite.
Mine.
Do.
PENHALE, HUEL
Tin.
Cassiterite, Galena-, Pyrites.
VOR.
Do.
Prosper, Huel.
Copper
and Tin.
Chalcotrichite, Cuprite, Fahlerz,
Mimetite.
Do.
TREMENHEERE.
Tin.
Do.
Tremearne.
Albite, Apatite, Fluor, ORTHO-
CLASE, Mica, Schorl, Topaz.
Do.
Trescow.
—
Cassiterite, Copper, Chalcopy-
rite.
Do.
TREWAVAS CLIFF
Copper.
Chalcopyrite, Chalybite, Fluor.
Do.
MINE.
Do.
Trewavas Head.
—
Albite, Schorl, Mica.
CHAPTER V.— DISTRIBUTIVE.
55
LIST or MINES, &c.— CORNWALL, KIBRIEE, West Division (Cont.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Breage (Cont.)
Tregoning Hill.
_
KAOLIN, FINITE.
Do.
Tresowes.
—
Stream Tin, Jasper, KAOLIN.
Do.
VOK, GRT. HUEL.
Tin and
Albite, Apatite? Blende, Cassi-
Copper.
terite, Chlorite, Chalcopyrite,
Copper, Dolomite, Melaconite,
Mica, Mispickel, Orthoclase,
Pyrites, Steatite, Talc ? Wol-
fram ?
Gertnoe.
GREAT WORK
Tin and
Blende, CASSITERITE, Chlorite,
CONSOLS.
Copper.
Chalcopyrite, Cuprite, Fahlerz,
Limonite, Melaconite, Mica,
Pyrites, Tourmaline.
Do.
LEEDS and ST.
Tin.
Cassiterite.
AUBYN.
Do.
Christopher, Huel
Tin.
Cassiterite, Mica, Orthoclase.
Do.
Fortune, South
Tin.
Cassiterite.
Huel.
Sithney.
Prospidnick,Huel
Lead.
Chlorite, Pyrites, Wolfram.
Do.
Penrose, Huel.
Anglesite, Calcite, Cerussite,
Chalcopyrite, Chalybite, Ga-
lena, Limonite, Linaiite, Mime-
tite, Pyrites, PYROMORPHITE,
Plumbic Ochre.
Do.
Rose, Huel.
Lead.
Anglesite, Cerussite, Chalybite,
Galena, Limonite, Pyromor-
phite, Quartz.
Do.
Sithney, Carn-
Tin.
Cassiterites, Pyrites.
meal.
Do.
Susan, Huel.
Tin and
Chalcopyrite, Copper, Cassiterite,
Copper.
Mica.
Do.
Trannack, Huel.
Copper.
Cassiterite, Chalcocite, Chryso-
Do.
Unity, Huel.
colla, Chalcopyrite, GARNET,
Mica, Pyrites, Schorl.
Cerussite, Chalcopyrite, Galena,
Pyrites.
Do.
Vor, East Huel.
Tin.
Cassiterite, Chalcopyrite, Mala-
chite.
Wendron.
Ann, Huel.
Tin.
Argentite, Cassiterite, Cerussite,
Felspar, Limonite, Mica, Silver.
Do.
BALMYNHEAK.
Tin.
Cassiterite.
Do.
BASSET and
Tin.
GRYLLS.
Do.
Hallebezac.
Cassiterite, Kaolin.
Do. •
LOVELL CONSOLS.
Tin.
Do.
LOVELL, EAST
Tin.
CASSITERITE.
HUEL.
Do.
LOVELL, NEW
Tin.
Cassiterite.
HUEL.
Do.
LOVELL, NORTH.
Tin.
Cassiterite.
Do.
TREVENNEN, NEW
Tin.
Cassiterite.
Do.
TREWORLIS.
Tin and
Cassiterite, Chalcocite, Chalcopy-
Copper.
rite, Magnetite, Mispickel,
Pyrites.
Do.
TRUMPET CON-
Tin.
Cassiterite, Felspar, Limonite,
SOLS.
Mica.
Do.
TRUMPET, EAST.
Tin.
Cassiterite.
56
CHAPTER V.— DISTEIBUTIVE.
LIST OF MINES, &c.— CORNWALL, KIRRIER, East Division,
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Gwennap.
Ale and Cakes.
Copper.
CHALCOPYRITE.
Do.
Barrier Mine.
Stannite.
Do.
CLIFFORD, NEW.
Tin and
Cassiterite.
Copper.
Do.
Consolidated Ms.
Copper.
BARYTES, Cassiterite, Chalcocite,
.
Chalcopyrite, Copper, Cuprite,
Gypsum, Melaconite, Molybde-
nite, Orthoclase, Pyrites, Kock
Crystal, Schorl.
Do.
Damsel, East
Copper.
Chlorite, Chalcocite, Chalcopy-
Huel.
rite, Copper, Fluor, Kaolin,
Lithomarge, Melaconite, Phar-
macosiderite, Pyrites.
Do.
DAMSEL, WEST
Tin.
Cassiterite, Fluor.
HUEL.
Do.
Fortune, Huel.
Copper.
Chlorite, Chalcopyrite, Felspar,
Limonite, Pyrites, Schorl.
Do.
Friendship, Huel
Albite, Blende, Molybdenite,
Wolframite.
Do.
Gorland, Huel.
Copper.
Asbolane, Chalcophyllite, Chal-
copyrite, Chalcotrichite, Ches-
sylite, Chrysocolla, CLINOCLASE,
Copper, Cuprite, Fluor, LIRO-
CONITE, Malachite, Mimetite,
Molybdenite, OLIVENITE, Opal,
PHARMACOSIDERITE, SCORODITE
Torbernite, Vivianite.
Do.
Jewel, Huel.
Blende, Chalcocite, Chalcopy-
rite, Fluor, Melaconite, Mis-
pickel, Petroleum ? Pyrites,
Tennantite.
Do.
Killiwerris.
Chalcopyrite, Galena.
Do.
PENNANCE.
Copper.
Chlorite, Chalcopyrite, Erubes-
cite.
Do.
Penstruthal and
Copper
Huel Buller.
and Tin.
Do.
Ting Tang.
Chalcocite, Chalcopyrite, Chal-
cophyllite, Chessylite, Chlorite,
Chrysocolla, Clinoclase, Cu-
Erite, Limonite, Malachite, Me-
iconite, Melanterite, Olivenite,
Pitchblende, PHARMACOSIDE-
RITE, Lithomarge, Pyrites,
Torbernite, Orthoclase.
Do.
TRESAVEAN and
Tin and
Blende, Chalcocite, Chalcopyrite,
TRETHARRUP.
Copper.
Chlorite, Copper, Epidote?Eru-
bescite, Fahlerz, Fluor, Galena,
Goslarite, Hornblende, Magne-
tite, Melaconite, Pyrites, Ten-
nantite.
Do.
Trethellan.
Copper.
Chalcocite, Goslarite.
Do.
United Mines.
Copper.
Cassiterite, BARYTES, Rock Crys-
tal.
St. Day.
POLDICE.
Tin.
Bitumen, Cassiterite, Copper,
Chalcopyrite, Galena, Pyrites,
Sulphur ? Wolfram, Wolframite.
CHAPTER V. -DISTRIBUTIVE.
57
LIST OP MINES, &c.— CORNWALL, KIBKIER, East Division (Cont.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
St. Day (Con.]
Vogue.
_
KAOLIN.
Gluvias.
EOSCROW UTD.
Chlorite, Mispickel, Pitchblende.
Do.
Burnt House.
—
Magnetite.
Do.
Treluswell.
—
Adularia? Hornblende.
Perran - ar-
Kerjiliack.
—
Graphite, in an elvan.
worthal.
Constantine.
CONSTANTINE
Iron.
LlMONITE.
MINE.
Do.
LOVELL, NEW
Tin.
Cassiterite.
EAST HUEL.
Do.
Granite Quarries
—
Fine imbedded crystals of OR-
THOCLASE ; occasional crystals of
Beryl and Topaz, but very rare.
Mawnan.
Cliffs on sea shore
—
Aragonite, Calcite, Chalcopyrite,
Oxide of Zinc.
Mabe,
Granite Quarries
—
Fine Orthoclase in the Granite, oc-
casionally Schorl; very rarely
Beryl and Topaz.
Budock.
Budock Vean.
—
Bournonite, Galena.
Do.
Falmouth.
Maenporth.
Swanpool, Mine.
Lead.
Rock Crystal, Calcite, Aragonite?
Galena, Pyrites, Rock Crystal.
Mylor.
Trefusis, Huel.
Lead.
Galena.
CORNWALL, PYDAR, West Division.
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
St. Agnes.
Barrow, Huel.
Tin.
Blende, Cassiterite, Scheelite,
Pyrrhotite.
Do.
Basset, Huel.
Copper.
Argentite, Copper, Cuprite, Ma-
lachite, Pitchblende, Torbernite
Do.
BLUE HILLS.
Tin.
Cassiterite.
Do.
CHARLOTTE, HUEL
Copper.
Cassiterite.
Do.
CHIVERTON, GRT.
Lead.
Galena.
WEST.
Do.
Clarence, Huel.
Tin.
Cassiterite, Smaltite.
Do.
Cligga Head.
Cassiterite, KAOLIN, Chalcopy-
rite, Wolfram.
Do.
Coates, HueL
Tin.
Agnesite, Bismite, CASSITERITE,
Mica, Orthoclase ; remarkable
pseudomorphs of Cassiterite
after Orthoclase, Schorl.
Do.
COIT, HUEL.
Tin.
Cassiterite.
Do.
Devonshire, Huel
Tin.
Chalcopyrite, Cassiterite, Fluor,
Pyrites.
Do.
FRIENDLY MINES
Tin.
Cassiterite.
Do.
Hallenbeagle and
East Downs.
Copper
and Tin.
Chalcopyrite, Pyrites.
Do.
Do.
James, Huel.
Kind, Huel.
Tin.
Torbernite, Chalcopyrite.
Apatite, Chalybite, Covellite,
Pyrrhotite, Topaz, VIVIANITE.
Do.
KITTY, HUEL.
Tin.
Blende, CASSITERITE, Chalcopy-
rite, Chlorite.
58
CHAPTER V.— DISTRIBUTIVE.
LIST OF MINES, &c.— COENWALL, PYDAK, West Division (Cont.j
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
St. Agnes.
KITTY, WEST
Tin.
Bismite, Cassiterite, STANNITE.
(Gont.)
HUEL (formerly
Huel Rock).
Do.
Music, Huel.
Copper.
Copper, Chalcocite, Chalcopyrite,
Cuprite, Malachite.
Do.
PENHALLS.
Tin.
Cassiterite.
Do.
Do.
POLBERKOW.
Polberrow, West.
Tin.
Tin and
Cassiterite, Chalcopyrite, Copper.
Cassiterite, Chalcopyrite, Fluor.
Do.
Polbreen.
Copper.
Tin.
Cassiterite.
Do.
PRUDENCE, HUEL.
Blende, Chalcopyrite, Towanite.
Do.
Pye, Huel.
Cassiterite.
Do.
To wan, Huel.
Tin.
Blende, Cassiterite, Chalcopy-
rite, Chalybite, Chlorite, Li-
monite.
Do.
TOWAN, SOUTH
Copper.
Bitumen, Chalcopyrite, Cha-
Do.
HUEL.
lybite, Chlorite, Limonite, Py-
rites.
Do.
TOWAN, NEW
Tin and
Cassiterite, Chalcopyrite, Pyrites,
Do.
HUEL.
TREVAUNANCE,
Copper.
Tin.
Cassiterite, Fahlerz, Fluor, Topaz.
HUEL.
Perranzabuloe
CHIVERTON (Old
Silver-Lead
Galena.
Cornubian).
Do.
CHIVERTON, EAST
Silver-Lead
Galena.
Do.
CHIVERTON MOOR
Silver-Lead
Galena.
Do.
CHIVERTON, NEW
Copper, Lead
Blende, Cerussite, Chalcopyrite,
(Huel Anna).
and Zioc.
Galena.
Do.
CHIVERTON, NEW
Lead, Zinc,
Blende, Cassiterite, Chalcopy-
CONSOLS (Bud-
Tin.
rite, Galena, Pyrites.
nick Consols).
Do.
CHIVERTON, GRT.
Lead.
Blende, Chalcopyrite, Dolomite,
SOUTH.
Galena.
Do.
CHIVERTON UTD.
Lead.
Galena.
Do.
CHIVERTON VAL-
Silver-Lead
Galena.
LEY.
Do.
CHIVERTON, WEST
Lead, Zinc.
BLENDE, CHALCOPYRITE, GALENA.
Do.
Duchy and Peru.
Iron.
Chalcopyrite, Chalybite, Galena,
MARCASITE.
Do.
Golden Consols.
Tin.
Cerussite, Galena, Pyromorphite,
Rock Crystal, Silver.
Do.
GOLDEN, EAST
Lead.
Galena.
HUEL.
Do.
Great St. George.
Copper.
Blende, Calamine, Chalcocite,
Chalnopyrite, Copper, Limo-
nite, Melaconite.
Do.
GRT. ST. GEORGE,
Blende.
WEST.
Do.
Hope, Huel.
Silver-Lead
BLENDE, GALENA, Chalcopyrite.
Do.
JEWELL, EAST.
Tin and
Cassiterite, Chalcopyrite.
Copper.
Do.
Mexico, Huel.
Argentite, Galena, Kerate, Silver
Do.
MINERAL BOTTOM
Lead.
Galena, Blende.
Do.
Penhale.
Lead.
Galena.
Do.
PERRAN CONSOLS
Tin.
Cassiterite.
(Huel Vlow).
Do.
PERRAN HUEL
Lead.
Galena.
VYVYAN.
CHAPTER V.— DISTRIBUTIVE.
59
LIST OF MINES, &c.— CORNWALL, PYDAR, West Division (Cont.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Perranzabuloe
(Cont.)
PERRAN SAINT
GEORGE.
Copper.
Blende, Chalcocite, Chalcopyrite,
Copper, Limonite, Melaconite.
Do.
RETALLACK, GRT.
Lead, Zinc.
Blende, Galena, Hornblende,
Silver.
Do.
RETALLACK,NTH.
Do.
VIRGIN, HUEL.
Lead.
Galena, Marcasite,
Cubert.
PENHALE AND
Lead.
Blende, Galena.
LOMAX.
Newlyn.
CARGOLL.
Silver-Lead
Blende, ^ Chalcopyrite, Galena,
Marcasite.
Do.
Fiddler's Green.
—
Do.
Rose, Huel.
Lead.
Galena, Pyrites.
Do.
ROSE AND CHI-
Lead.
Blende, Galena.
VEHTON.
Crantock.
TREREW.
Lead. Galena.
CORNWALL, PYDAR, East Division.
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
St. Enoder.
CHYTANE.
Tin and
Cassiterite, KAOLIN.
China-clay.
St. Columb.
ROYALTON.
Tin.
Cassiterite.
Do.
TREWORLOCK.
Lead.
Galena.
Do.
Lanivet.
Trugoe.
MULBERRY HILL.
Tin.
Bismuth, Erythrite, Jasper, Opal.
Cassiterite.
Do.
RETIRE.
Iron.
Hematite, Limonite.
Do.
REPERRY.
Tin.
Antimonite, Berthierite, Cas-
siterite, Cervantite, Jameso-
nite.
Padstow.
ST. ISSEY.
Copper,
Chalcopyrite, Galena.
Lead.
Do.
TRELEATHER,
Copper,
Chalcopyrite, Galena.
NORTH.
Silver-Lead.
St. Merryn.
— 1
Bournonite.
CORNWALL, POWDER, West Division.
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals,
St. Feock.
St. Kea.
Do.
Carnon Stream
Works.
CREEGBRAWSE &
PENKIVELL.
Falmouth, Huel.
_
Copper
and Tin.
Silver-Lead,
and Man-
ganese.
CASSITERITE, GOLD.
Chalcopyrite, Cassiterite, PY-
RITES.
Blende, Cassiterite, Cerussite,
Chlorite, Erubescite, Galena,
Pharmacosiderite, PYRITES, Py-
romorphite, Silver, VIVIAMTE.
60
CHAPTER V.— DISTRIBUTIVE.
LIST OF MINES, &c.— CORNWALL, POWDER, West Division (Cont.)
Kenwyn.
BOSCAWEN.
Copper,
Chalcopyrite, Blende.
Tin, Zinc.
Do.
JANE, NORTH.
Tin, Silver-
Cassiterite.
Lead.
Do.
Unity Wood,
Cassiterite, Chalcopyrite, Chlo-
Huel.
rite, Fluor, Pyrites, Schorl.
St. Erme.
Garras.
Lead.
ALLOPHANE, Blende, Calcite,
Dolomite, Galena.
Ladock.
—
Cassiterite, Gold, Hematite, Li-
monite, Pyrites.
Veryan.
Pennare Point.
—
Asbestos, Hornstone, Steatite.
CORNWALL, POWDER, East Division.
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
St. Dennis.
Hendra.
Mica.
Do.
Kaolin, Cassiterite.
St. Stephens.
CROW HILL, NEW
Lead.
Galena, Gold? Pyrites.
Do.
Dowgas.
—
Actinolite, Cassiterite, Horn-
blende, Kaolin, Pyrites, SchorL
Do.
FORTESCUE,HUEL
Do.
GRENVILLE, HUEL
Tin.
Cassiterite.
Do.
Terras.
Tin.
Kaolin, Cassiterite.
Gorran.
Gorran Haven.
Calcite.
St. Ewe.
CHANCE, HUEL.
ANNABERGITE, Chalybite, Mille
rite, Niccolite.
Do.
Pengelly Mine.
ANNABERGITE, Chalybite, Mille -
rite, Niccolite.
St. Mewan.
Brecon, Cam.
Cassiterite, Gold, Silver.
Roche.
BEAM MINE.
Tin.
Cassiterite, Kaolin, Melaconite,
Olivenite, Pharmacosiderite,
Talc, Wolfram, Wavellite?
Do.
BRYNN MINE.
Tin.
Cassiterite.
Do.
BRYNNROYALTON
Tin.
Cassiterite.
Do.
Cost all Lost.
Bismite, Cassiterite.
Do.
ROYALTON, GRT.
Tin.
Cassiterite.
St. Austell.
CARCLAZE.
Tin and
Kaolin.
Cassiterite, Galena, Gilbertite,
KAOLIN, Schorl.
Do.
Carvath United.
Copper
Chalcocite, Cuprite.
and Tin.
Do.
CHARLESTOWN
Tin and
Actinolite, Cassiterite, Chaly-
UTD. MINES.
Copper.
bite, Limonite, Serpentine?
Do,
CONSOLIDATED,
Annabergite, Barytes, Cobaltite,
ST. AUSTELL.
Copper, Pitchblende, Smaltite.
CHAPTER V.— DISTRIBUTIVE.
61
LIST OF MINES, &c.— CORNWALL, POWDER, East Division (Gout.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals
St. Austell
Crinnis.
Copper.
Chalcopyrite, Chalybite, Childre-
( Cont. )
nite, Copper, FAHLERZ, Galena,
Scorodite, Silver, Pyrites.
Do.
CUDDKA.
Tin.
Cassiterite.
Do.
ELIZA, HUEL.
Tin and
Cassiterite, Chalcopyrite.
Copper.
Do.
ELIZA CONSOLS,
Copper
Cassiterite, Chalcopyrite.
HUEL.
and Tin.
Do.
GOONBAKKOW.
Tin and
Cassiterite, Kaolin, Zippaeite ?
Kaolin.
Do.
GOVEB.
Tin.
Cassiterite.
Do.
GKEAT DOWGAS.
Tin.
Bismuth, Bismuthinite, Cassi-
terite, Copper, Fluor.
Do.
Grt. Hewas Utd.
Tin.
Cassiterite, Liroconite, Mispickel.
Do.
Hill Mine.
Tin.
Cassiterite, Orthoclase, Tourma-
line, Topaz.
Do.
MINEAR DOWNS.
Cassiterite.
Do.
Pembroke.
Copper.
Chalybite, Chalcopyrite, Chalco-
cite, Copper, Kaolin, Melaco-
nite, Pyrites.
Do.
Pentewan.
Stream Tin, Gold.
Do.
POLGOOTH.
Tin.
Amethyst, Calcite, Cassiterite,
Chalcopyrite, Chlorite, Dolomite
Erythrite, Pyrites, Smaltite.
Do.
POLMEAR, HUEL.
Copper
Chalcopyrite, Pyrites.
and Pyrites.
Do.
KOCK HILL.
Cassiterite.
Do.
RUBY & KNIGH-
Iron.
LIMONITE, Hematite, Black
TOR.
Quartz.
Do.
SHILTON (Bon-
Tin.
Cassiterite.
ney).
Do.
Stenna Gwynn.
Tin.
Apatite, Autunite, Oassiterite,
FLUELLITE, FLUOR, Gilbertite,
Mesolite? Natrolite, Opal, Stan-
nite, Talc, Tavistockite, Torber-
nite, Wavellite? Wolfram.
Do.
Trenanon.
Blende.
Do.
Virgin, Huel.
Tin.
Cassiterite.
St. Blazey.
East Crinnis.
Copper.
Blende, Chalcocite, Chalcopyrite,
Chalybite, Copper, Melaconite,
Pyrites, Rock Crystal.
Do.
PAR CONSOLS.
Copper
Blende, Cassiterite, Chalcopy-
and Tin.
rite, Chlorite.
Do.
PEMBROKE, NEW.
Copper
and Tin.
Cassiterite, Chalcopyrite.
Do.
Tywardreath.
PEMBROKE, OLD.
Fowey Consols.
(Lanescot.)
Copper.
Copper.
Chalcopyrite.
Actinolite, Antimonite, Apatite,
Bismuthinite, Blende, Cala-
mine, Chalcocite, Chalcopyrite,
Chalcotrichite, Chalybite, Co-
baltite, Copper, Cuprite, FRAN-
COLITE, Niccolite, Magnetite,
Marcasite, Melaconite, Melan-
terite, Millerite, Pyrites, Silver,
Stannite, Wood Tin.
Do.
FOWEY CONSOLS,
Copper.
Chalcopyrite.
SOUTH.
62
CHAPTER V.— DISTEIBUTIVE.
LIST OP MINES, &c.— CORNWALL, POWDER, East Division (Cont.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Fowey.
Menabilly.
_
Molybdenite.
Luxulyan.
Luxulyan, Quar-
—
ORTHOCLASE, SCHORL.
ries near.
Lanlivery.
MAUDLIN MINES.
Copper
and Tin.
Calcedony, Cassiterite, Chaly-
bite, Chlorite, Covellite, Cron-
stedtite, Fluor, Garnet, Jasper,
Melanterite, Mispickel, Opal,
Pyrites, Pyrrhotite, Scheelite,
Wolfram.
Do.
Prideaux Wood
Tin.
Cassiterite.
Mine.
Lostwithiel.
FORTESCUE, NTH.
Lead.
Galena.
HUEL.
Do.
RESTORMEL.
Iron.
AGALMATOLITE, Amethyst, Ba-
rytes, Bismuth, Bismite, Goe-
thite, Hematite, LIMONITE,
Manganite, PSILOMELANE, Pyro-
lusite, Rock Crystal, Zippseite.
Do.
Terrace Hill
—
Axinite.
Quarry.
CORNWALL, TRIGG.
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
St. Minver.
Pentire Glaze.
—
Antimonite, CERUSSITE, Cervan-
tite, Pyrolusite.
Endellion.
Boys, Huel.
Antimonite, BOURNONITE, Cer-
vantite, Erubescite, Jamesonite,
Mimetite.
Do.
Port Isaac.
—
Antimonite, Cervantite, Jameso-
nite.
Do.
Port Quin Cliffs.
—
Jamesonite.
Do.
ROYAL SAMPSON.
Silver-Lead.
Galena.
Do.
Trevinnock.
—
Bleinierite, Cervantite, Jameso-
nite.
St. Kew.
Pendogget.
—
Anglesite, Antimonite, Jameso-
nite.
Do.
PENGENNA.
Lead.
Galena.
Bodmin.
Bodmin Moor.
—
Stream Tin.
Do.
ESTHER UNITED,
Tin.
Cassiterite.
HUEL.
St. Breward.
ONSLOW CONSOLS,
Copper.
Chalcopyrite.
GREAT.
St. Teath.
Do.
ARCHIE, HUEL.
OLD TREBURGETT
Copper, Lead
Lead, Silver.
Chalcopyrite, Galena.
Blende, Chalcopyrite, Pyrites,
Polytelite.
Do.
TREGARDOCK.
Lead, Copper
Chalcopyrite, Galena.
CHAPTER V.— DISTEIBUTIVE.
63
LIST OP MINES, &c.— CORNWALL, WEST.
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
St. Veep.
_
Asbestos.
Lanreath.
HERODSFOOT.
Silver-Lead.
Bournonite, CALCITE, Chalcopy-
rite, Fahlerz, Galena, Horn-
stone, Pyrites.
Duloe.
HEEODSFOOT,
Silver-Lead.
Calcite, Galena.
SOUTH.
Liskeard.
AMBROSE LAKE.
Tin.
Cassiterite.
Do.
Looe Mills Hill
—
Anatase.
Quarry.
Do.
St. Neot.
Tin.
Cassiterite.
St. Cleer.
CARADON CON-
Copper.
Chalcopyrite, Cuprite.
SOLS.
Do.
CARADON, SOUTH.
Copper.
Chalcocite, Chalcopyrite, Cu-
prite, Fluor.
Do.
CARADON, WEST.
Copper.
Chalcocite, Chalcopyrite, Cu-
prite, Copper, Fluor.
Do.
Cheesewring.
—
Actinolite, Asbestos, Orthoclase,
Soapstone? Schorl.
Do.
Do.
CRADDOCK MOOR.
GLASGOW CARA-
Copper.
Copper.
Chalcopyrite, Cuprite.
Chalcopyrite, Cuprite.
DON CONSOLS.
Do.
GONAMENA.
Copper.
Chalcopyrite, Cuprite.
Do.
St. Neot.
Ludcott, Huel.
HAMMETT.
Tin.
Pyrargyrite, Silver.
Cssiterite.
Do.
TIN VALLEY.
Tin.
Cassiterite.
Do.
TREVENNA, HUEL
Tin and
Cassiterite, Chalcopyrite.
Warleggan.
GRT. TREVEDDOE
Copper.
Tin.
Cassiterite.
AND CABILLA.
CORNWALL, LESNEWTH.
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Tintagel.
Cliffs.
_
Albite, Anatase, ARAGONITE
Brookite?
Do.
DELABOLE SLATE
Adularia, Albite, Anatase, Cal-
QUARRIES.
cite, Goethite, ROCK CRYSTAL,
Rutile?
Do.
KING ARTHUR
Silver-Lead.
Galena.
MINE.
Forrabury.
Cliffs.
—
Anthracite.
Do.
Boscastle.
—
Graphite.
Davidstow.
Hematite, Limonite.
Laneast.
Lettcott.
Manganite, Psilomelane.
Alternun.
—
Stream Tin, Gold.
64
CHAPTER V.— DISTRIBUTIVE.
LIST OF MINES, &c.— CORNWALL, EAST.
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Launceston.
Do.
Five Lanes.
Pollaphant.
—
Hornblende.
Calcite, Serpentine, STEATITE.
Callington.
Creva Wood.
—
Pyrolusite.
Do.
COLQUITE AND
Copper.
Chalcopyrite.
CALL. UTD.
Do.
Duchy Huel.
Argentite, Kerate, Pyrargyrite,
Silver.
Do.
DEER PARK.
Tin.
Cassiterite.
Do.
EXCELSIOR.
Tin and
Cassiterite, Chalcopyrite.
Copper.
Do.
George and Char-
—
Bismuthinite, Childrenite, Chlo-
lotte.
rite.
Do.
FLORENCE, HUEL.
Copper.
Chalcopyrite.
HATE VALLEY.
Tin.
Cassiterite.
Do.
HOLMBUSH AND
Copper.
Chalcopyrite.
Do.
KELLY BRAY.
Do.
Do.
KELLY BRAY.
NEW GREAT CON-
Silver-Lead.
Tin and
Chalcopyrite, Galena.
Cassiterite, Chalcopyrite.
SOLS.
Copper.
Do.
PRINCE OF WALES
Copper.
Chalcopyrite.
SOUTH.
Do.
PRINCESS OF
Copper
Cassiterite, Chalcopyrite.
WALES.
and Tin.
Do.
REDMOOR.
Copper.
Cassiterite, Chalcopyrite.
Do.
St. Vincent,
ARGENTITE, Chalcopyrite, KE-
Huel.
RATE, SILVER.
St. Ive.
CARADON, GRT.
Copper.
Chalcopyrite.
Do.
GILL, HUEL.
Copper
Chalcopyrite, Galena.
and Lead.
Do.
GILL, GLASGOW
Lead.
Galena.
HUEL.
Do.
IDA, HUEL.
Silver-Lead.
Galena.
Do.
TRELAWNEY,
Copper.
Blende, Barytes, Chalcopyrite,
NEW.
Galena, Fluor, Hornstone.
Linkinhorne.
Do.
CARADON, EAST.
CARADON AND
Copper.
Copper
Chalcopyrite, Cuprite.
Blende, Chalcopyrite.
PH(ENIX.
and Zinc.
Do.
Do.
MARKE VALLEY.
PHCENIX.
Copper.
Copper
and Tin.
Chalcopyrite, Cuprite.
Cassiterite, Chalcopyrite, Chal-
cotrichite, CUPRITE, Copper,
Chrysocolla, Malachite, Oli-
venite.
Do.
PHCENIX, EAST.
Copper.
Chalcopyrite.
Do.
PHOZNIX, WEST.
Copper.
Chalcopyrite.
Do.
Rose Down, West
Copper.
Chalcopyrite.
Stokeclims-
KITT HILL.
Tin and
Cassiterite, Chalcopyrite.
land.
Copper.
Do.
KITT HILL, EAST.
Tin and
Cassiterite, Chalcopyrite.
Copper.
Do.
KITT HILL, STH.
Tin.
Cassiterite.
Calstock.
ARTHUR, HUEL.
Copper
Bismuthinite, Cassiterite, Chal-
and Tin.
copyrite.
Do.
Brothers, Huel.
Copper.
ARGENTITE, Blende, Chalybite,
Galena, PYRARGYRITE, SILVER.
Do.
CALSTOCK CON-
Copper.
Chalcopyrite.
SOLS.
CHAPTER V.— DISTRIBUTIVE.
65
LIST OF MINES, &c.— CORNWALL, EAST (Cont.)
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Calstock
DBAKEWALLS.
Tin and
Cassiterite, Molybdenite, Wol-
(Cont.)
Do.
DEAKEWALLS,
Copper.
Tin.
fram, Wolframite.
Cassiterite.
WEST.
Do.
GUNNISLAKE.
Copper.
Antimonite, Chalcocite, Chal-
cophyllite, Chrysocolla, Copper,
Cuprite, Cyanosite, Libethenite,
Liroconite, Malachite, Melaco-
nite, Olivenite, Torbernite,
Wolfram.
Do.
GUNNISL A K E
CLITTEKS.
Copper
and Tin.
Chalcopyrite.
Do.
HAKEWOOD CON-
Copper.
Chalcopyrite.
SOLS.
Do.
HAWKMOOR.
Copper.
Chalcopyrite.
Do.
KINGSTON
Copper.
Chalcopyrite.
DOWNS.
Do.
Lee, Huel.
Antimonite, Cervantite, Galena,
Jamesonite.
Do.
Do.
OKEL TOB.
PRINCE OF WALES
Copper.
Copper
Chalcopyrite.
Chalcopyrite.
and Tin.
Do.
PRINCE OF
Copper.
Chalcopyrite.
WALES, WEST.
Menheniot.
Do.
Clicker, Tor.
MARY ANN,
Silver-
Asbestos, Calcite, Serpentine.
BARYTES, Calcite, Pyrites, Rock
HUBL.
Lead.
Crystal.
Do.
TRELAWNY, HUEL
Silver-
Barytes? Calcite, Galena.
Lead.
Do.
Treweatha.
Silver-
Galena.
Lead.
66
CHAPTER V.— DISTRIBUTIVE.
DEVONSHIRE.
(In Devon, as the Localities are more widely separated than in Cornwall,
they are somewhat arbitrarily arranged.)
SOUTHERN PARLIAMENTARY DIVISION.
Situation or
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Lifton.
Harris, Huel.
Silver-Lead.
Galena.
Do.
HEALE.
Manganese.
Psilomelane, Pyrolusite.
Do.
Henry, Huel.
Manganese.
Psilomelane, Pyrolusite.
Do.
LIFTON MINES.
Manganese.
Psilomelane, Pyrolusite.
Do.
Mary Emma,
Tin.
Cassiterite.
Huel.
LewTren chard
LEW WOOD.
Manganese.
Psilomelane, Pyrolusite.
Okehampton.
—
Amethyst, Andalusite, Axinite,
Chiastolite ? Jasper, Opal,
Eock Crystal, Schorl,
Do.
BELSTONE CONS.
Copper.
Chalcopyrite, Garnet, Limonite.
Do.
Maria, East Huel.
Copper.
Chalcopyrite.
Do.
Copper Hill.
Axinite, Garnet.
Do.
FOREST HILL.
Tin and
Axinite, Cassiterits, Galena,
Lead.
Garnet.
Do.
FORSDON MINE.
Copper.
Axinite, Chalcopyrite, Garnet.
Do.
Holstock.
Chiastolite ?
Do.
Ivey Tor.
Copper.
Axinite, Bismuthinite, Chalcopy-
rite, Marcasite.
Do.
Meldon Quarry.
—
Garnet, Pyrrhotite.
Do.
Sticklepath.
—
Actinolite, Axinite, Hornblende.
Do.
Lidford.
Zeal Consols, Sth.
Frederick, Huel.
Copper.
Tin.
Chalcopyrite.
Cassiterite.
Do.
Lidford Consols.
Tin.
Cassiterite.
Do.
Swincombe Vale.
Tin.
Cassiterite.
Marystow.
ALLIFORD.
Manganese.
Psilomelane, Pyrolusite.
Do.
CALLACOMBE.
Copper
Blende, Chalcopyrite.
and Blende.
Do.
Dippertown.
Manganese.
Psilomelane, Pyrolusite.
South Syden-
Concord.
Silver-Lead
Chalcopyrite, Galena.
ham.
& Copper.
Milton Abbot.
CAWSAND VALE.
Copper.
Chalcopyrite.
Do.
Chillaton.
Manganese.
Psilomelane, Pyrolusite.
Do.
Hogston.
Manganese.
Psilomelane, Pyrolusite.
Lamerton.
CALLACOMBE,EST.
Copper.
Chalcopyrite.
Do.
CARDWELL.
Manganese.
Psilomelane, Pyrolusite.
Do.
MARIA, WEST &
FORTESCUE.
Copper
and Lead.
Chalcopyrite, Galena.
Mary Tavy.
Betsy, South
Huel.
Copper
and Lead.
Do.
Devon Huel
Copper.
Union.
Do.
FRIENDSHIP,
Copper.
Axinite, Blende, Calcite, CHAL-
HUEL.
COPYRITE, Chalybite, Chlorite,
Fluor, Galena, Pyrites, KOCK
CRYSTAL, Scheelite, Wolfram?
Do.
Friendship, Nth.
Huel.
Copper
and Lead.
Chalcopyrite, Galena.
Do.
Peter Tavy and
Copper.
Chalcopyrite.
Mary Tavy Cns.
CHAPTER V.— DISTRIBUTIVE.
67
LIST OF MINES, &c.— DEVONSHIRE, SOUTHERN DIVISION (Cont.)
Situation or
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Mary Tavy
PRINCE ARTHUR
Silver-Lead.
Chalybite, Galena, Limonite,
(Cont.)
CONSOLS (Old
Vivianite.
Huel Betsy.)
Tavistock.
BEDFORD CONLS.
Copper.
Chalcopyrite.
Do.
BEDFORD
UNITED.
Copper.
Chalcopyrite, CHALCOTRICHITE,
Chalybite, Clinoclase, CUPRITE,
Olivenite, Pyrites, Torbernite.
Do.
Black Down.
—
Niccolite, PSILOMELANE, PYROLU-
SITE, Rhodonite.
Do.
Brent, Tor.
Actinolite, Axinite, Garnet, Jas-
—
per, Psilomelane, Pyrolusite.
Do.
COURTNEY, HUEL.
Copper.
Chalcopyrite.
Do.
CREBOR.
Copper.
Bitumen, Chalcopyrite, Chaly-
bite, Childrenite, Chlorite,
Copper.
Do.
CRELAKE.
Copper.
Chalcopyrite.
Do.
Crowndale.
Copper.
Chalcopyrite, Marcasite.
Do.
DEVON & CORN-
Copper.
Antimonite, Bismuthinite, Chal-
WALL UNITED.
copyrite, Childrenite, Chlorite.
Do.
Devon & Courte-
Copper.
CHALCOPYRITE, Copper, Galena.
nay.
Do.
DEVON GREAT
Copper.
CHALCOPYRITE, Copper, Mispickel
CONSOLS.
Do.
Devon Gt. Con-
Copper.
Chalcopyrite.
sols, East.
Do.
Gawton.
Copper.
Chalcopyrite.
Do.
GUNNISLAKE,
Copper.
Chalcopyrite.
EAST, & SOUTH.
BEDFORD.
Do.
NEW GT. CONSLS.
Copper.
Chalcopyrite.
Do.
KUSSELL, HUEL.
Tin.
Cassiterite.
Do.
Russell, Est. Huel
Copper.
Chalcopyrite.
Do.
KUSSELL, NEW
Copper.
Chalcopyrite.
EAST HUEL.
Do.
Do.
Tavy Consols.
United Mines.
Copper.
Tin and
Chalcopyrite.
Cassiterite, Chalcopyrite.
Copper.
Do.
"Wills worthy
CHALCOPYRITE, Erythrite, Silver.
Mine.
Bickleigh.
Bickleigh Vale,
Huel Phoanix.
Copper
and Tin.
Cassiterite, Chalcopyrite.
Sampford Spi-
Huckworthy
Copper.
Chalcopyrite.
ney.
Bridge.
Do.
Kobert, Huel.
Copper.
CHALCOPYRITE, Limonite, Pyrites,
Rock Crystal.
Do.
Robert, North
Copper.
Chalcopyrite.
Huel.
Prince Town.
WHITE WORKS.
Tin.
Cassiterite.
Buckland
Buller & Bertha.
Copper.
Chalcopyrite.
Monachorum.
Do.
Bertha, East.
Copper.
Chalcopyrite.
Do.
Devon Poldice.
Tin & Cop.
Cassiterite, Chalcopyrite.
Do.
Devon Huel Bul-
Copper.
Chalcopyrite.
ler.
Do.
Franco, Huel.
Copper.
Cassiterite, Chalcopyrite, Chaly-
bite, Fluor, FRANCOLITE.
68
CHAPTER V.— DISTEIBUTIYE.
LIST OP MINES, &c.— DEVONSHIRE, SOUTHEKN DIVISION (Cont.)
Situation or
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Buckland
Lady Bertha.
Copper.
Chalcopyrite.
Monachorem
(Cont.)
.
Do.
Lady Bertha,
Copper.
Chalcopyrite.
South.
Do.
VIRTUOUS LADY.
Copper.
Anatase, Brookite? CHALCOPY-
RITE, Chalybite, Chlorite,
Fluor, MARCASITE, Mispickel,
Pyrites, Titanite.
Beerferris.
Beeralston Mines.
Silver-Lead.
Anglesite, Blende, Bournonite,
Calcite, Calcedony, Chalcopy-
rite. Chalybite, Dolomite,
Fahlerz, FLUOR, Galena, Horn-
stone, Mimetite, Pyromorphite,
Pyrrhotite.
Do.
Queen of Tamar.
Copper
Chalcopyrite, Galena.
and Lead.
Do.
South Hooe.
Dolomite, Fluor.
Do.
SOUTH WARD.
Silver-Lead.
Galena.
Do.
Tamar Consols.
Silver-Lead.
Blende, Cassiterite, CHALCOPHYL-
LITE, Fluor, Galena, MARCASITE,
Mispickel, Rock Crystal.
Do.
Tamar, East.
Lead.
Anglesite, Cerussite, Chessylite,
Galena, Hornstone, Malachite.
Do.
TAMAR VALLEY.
Silver-Lead.
Galena.
Whitchurch.
Sortridge Consls.
Copper.
Chalcopyrite.
Plymouth.
Many Quarries.
—
CALCITE.
Plympton.
—
Chalybite, Kaolin.
Do.
BOTTLE HILL,
Tin.
Cassiterite.
EAST.
Do.
MARY HUTCHINGS
Tin.
Cassiterite.
HUEL.
Do.
Shaugh.
Iron.
Chalybite, Limonite.
Do.
Sydney, Huel.
Tin.
Cassiterite.
Ivybridge.
Chiastolite ? Orthoclase.
Dartmoor.
—
Andalusite? Cassiterite, Garnet,
Hematite, Hornblende, Tour-
maline.
Do.
Haytor.
—
Agate, Calcedony, Garnet, Hay-
torite, Hornblende, Magnetite,
Orthoclase, Opal.
Do.
Sheepstor.
Cassiterite, Gold.
Buckfastleigh.
—
Aragonite, Hematite, Limonite,
Malachite.
Do.
BROOKWOOD.
Copper.
Chalcopyrite.
Do.
EMMA, HUEL.
Copper.
Chalcopyrite.
CHAPTER V.— DISTRIBUTIVE.
69
LIST OF MINES, &c.— DEVONSHIRE, EAST DIVISION.
Situation or
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Chagford.
VITIFER CONSOLS,
Copper.
Chalcopyrite, Schorl.
NEW.
M o r e t o n -
Gidleigh.
—
Kock Crystal.
hempstead.
Christow.
EXMOUTH.
Copper and
Chalcopyrite, Galena.
Silver-Lead.
Do.
Exmouth. North
Copper and
Huel.
Silver-Lead.
Do.
Exmouth, South
Silver-Lead.
Huel.
Do.
FRANK MILLS.
Silver-Lead.
Galena.
North Bovey.
BIRCH TOR, NEW
Tin.
Cassiterite.
and VITIFER.
Do.
Birch Tor, East.
Tin.
Cassiterite.
Do.
King's Oven.
Tin.
Cassiterite.
Bovey Tracey.
—
Apatite, Diallogite, Hornblende,
LIGNITE, Lithomarge, Mica,
Orthoclase, RETINUE, TOURMA-
LINE.
Do.
DEVON HUEL
Copper.
Chalcopyrite.
FRANCES.
Do.
Yaruer.
Copper and
Mundic.
Chalcopyrite, Pyrites.
Lustleigh.
—
Beryl, Garnet, Hennatite, Opal.
Ilsington.
Atlas.
Tin & Iron.
Cassiterite, Limonite.
Do.
Hatherley.
Iron.
Limonite, Magnetite.
Do.
Sigford.
Copper
and Tin.
Cassiterite, Chalcopyrite.
Do.
Smallacombe.
Iron.
Limonite, Hematite.
Ashburton.
Ashburton Cons.
Copper.
Chalcopyrite.
Do.
Ashburton Mine.
Cassiterite.
Do.
Ashburton Untd.
Tin and
Cassiterite, Chalcepyrite.
Copper.
Do.
Ashburton, West.
Copper
and Tin.
Cassiterite, Chalcopyrite.
Do.
Buckland in the
Magnetite.
Moor.
Do.
Devon Gt. Huel
Ellen.
Copper
and Tin.
Cassiterite, Chalcopyrite.
Do.
Do.
Devon, New.
Smith's Wood.
Copper.
Chalcopyrite.
Cassiterite.
Do.
United, Dart.
Copper.
Chalcopyrite.
Do.
VICTORIA (Arun-
Copper.
Chalcopyrite.
del.)
Do.
Torquay.
Victoria, New.
Babbicombe Bay.
Copper.
Chalcopyrite.
BARYTES, Beekite, Calcite.
Do.
Mary Church.
—
Agate.
Do.
Torbay.
—
Aragonite, BEEKITE.
Do.
Torbay Mine.
Iron.
Hematite, Limonite.
Paignton.
GTMTON.
Iron.
Hematite, Limonite.
Brixham.
FIVE ACRE.
Iron.
Hematite, Limonite.
Do.
PROSPER, HUEL.
Iron.
Hematite, Limonite.
Do.
PARKINS.
Iron.
Hematite, Limonite.
Do.
SHARPHAM.
Iron.
Hematite, Limonite.
Dawlish.
—
Calcite, MURCHISONITE.
Chudleigh.
Apatite, Kalinite, Petroleum,
Psilomelane, Schorl.
70
CHAPTER V.— DISTEIBUTIVE.
LIST OP MINES, &c.— DEVONSHIRE, EAST DIVISION (Cont.)
Situation or
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Chudleigh
(Cont.)
Exeter.
Do.
Budleigh Sal-
terton.
Sidmouth.
Axminster.
Hennock.
Haldon.
Heavitree.
Seaton.
—
BAKYTES, Blende, Cerussite, Ga-
lena, Hematite, Malachite.
Chert, Flint.
Orthoclase, MURCHISONITE.
Agate, Orthoclase.
Celestite, Flint.
Asbestos.
DEVONSHIRE, NORTHERN PARLIAMENTARY DIVISION.
Situation or
Parish.
Locality.
Produce of
Mines.
More remarkable Minerals.
Buckland
_
Hematite, Jasper, Limonifce.
Br ewer.
Do.
Orleigh Court.
Chert, Flint, Psilomelane.
Bideford.
—
Anthracite, Hematite, Psilome-
lane.
Ilfracombe.
Aragonite, Hematite, Millerite.
Do.
Combmartin
Silver-Lead.
Aragonite, Antimonite, Blende,
Mines.
Calcite, Chalcopyrite, Chessy-
lite, Fahlerz, Galena, Hematite,
Malachite, Marcasite, Millerite,
Pyrites, Rock Crystal, Silver,
Umber, Yellow Ochre.
Do.
West Down.
—
Hematite, Psilomelane.
Barnstaple.
Abbotsham.
—
Anthracite.
Do.
Bickington.
—
Pyrites.
Do.
Bishop's Tawton.
Pyrites.
Do.
Bratton Fleming.
—
Hematite, Limonite.
Do.
East Down.
—
Hematite, Limonite, Psilomelane,
Umber, Yellow Ochre.
Do.
Georgeham.
—
Hematite, Limonite, Psilomelane,
Pyrolusite.
Do.
Hawkridge "Wood
—
Anthracite.
Do.
Landkey.
—
Blende, Galena.
Do.
Viveham.
—
Hematite, Limonite,Psilomelane,
Pyrolusite, Pyrites.
Nth. Moulton.
BAMPFYLDE, NEW
Copper.
Chalcopyrite.
Do.
BRITTANIA and
Copper.
Chalcopyrite, Erubescite, Fah-
PRINCE REGENT.
lerz, GOLD.
Do.
Molland Mine.
Copper.
Chalcopyrite, Fahlerz.
Sth. Moulton.
Filleigh.
—
WAVELLITK.
Newton St.
—
Hematite, Psilomelane.
Cyres.
Upton Pyne.
—
Manganite, PSILOMELANE, PYRO-
LUSITE, Rhodonite, Wad.
Collumpton.
Anthracite.
Blackdo wn
—
Agate, Chert, Flint.
Hills.
Ex moor.
—
Chalybite, Goethite, Limonite.
Lundy Island.
—
Chalcopyrite, Hornblende, Mag-
netite, Orthoclase, Rock Crys-
tal, Topaz, Tourmaline.
CHAPTER VI.— PABAGENETIC.
71
CHAPTER VI.
PARAGENETIC
That the composition of a mineral lode often varies with a variation of the
enclosing country is a very old observation. The subject was largely considered
by Mr. W. J. Henwood, in his great work on the Metalliferous Deposits of
Cornwall and Devon ; and, although it well deserves further elucidation, this
belongs rather to a geological than to a mineralogical work.
A more strict paragenesis would deal with those groups of minerals which are
immediately associated with each other, or even in contact ; and fortunately
such an enquiry may be conveniently prosecuted wherever a well-selected series
of mineral specimens exists.
The object of this chapter is rather to draw popular attention to this branch
of the subject than to follow it up in detail, as many more observations should
be specially made in this direction before any very definite laws can be announced.
It is well-known, however, that certain minerals are, to use a miner's term,
"congenial" to others ; and a few such observations are here set down.
Of all the minerals known in the two western counties, Quartz is the most
widely diffused, and most generally associated with other minerals. So general is
its occurrence, that its peculiar varieties must be studied in order to lead to any
definite results.
The following examples of paragenesis will be recognised as common ; but it
would be well if students would carefully register and accumulate observations
on this part of the subject, and make them publicly known through any con-
venient channel.
QUAKTZ is commonly associated with Orthoclase.
Mica.
„ „ Schorl.
Chlorite.
„ ,, Chalybite.
„ Calcite.
,, Dolomite.
Barytes.
„ Fluor.
,, Cassiterite.
,, Pyrites.
„ Chalcopyrite.
Limonite.
Goethite.
„ Wolfram.
,, Cuprite.
Copper.
Galena.
„ Blende.
,, Bournonite, &c.
„ Chlorite.
Mispickel.
Pyrites, &c.
„ Fluor.
Galena.
Blende.
Chalybite.
Dolomite, &c.
Pyrites.
„ Chalcopyrite.
,, Blende, &c.
„ Fluor.
„ Mispickel.
Limonite, &c.
CASSITERITE
CHALCOPYRITE
GALENA
PYRITES
72
CHAPTER VI.— PABAGENETIC.
CUPRITE is commonly associated with Copper.
Malachite.
FLUOR
SERPENTINE
Besides the above, many notices of
in the alphabetical part of the work.
Chessylite, &c.
Wolfram.
Chlorite.
Orthoclase.
Chalybite, &c.
Steatite.
Diallage.
Asbestos.
Chrysocolla, &c,
associated groups of minerals will be found
A HAND-BOOK
TO THE
MINEKALOGY OF
CORNWALL AND DEVON.
PART II.
A.
AGNESITE.
Accretion. Increase by external addi-
tions of new matter ; applied only to
inorganic substances.
Acicular. Needle-like. Long, slender,
and straight prisms are termed acicular.
Acicular Arseniate of Copper. See
Olivenite.
Acid. A substance containing Hydro-
gen, which is displaceable by a metal — a
salt being formed. In some instances it
is necessary that the metal be presented
in the form of an hydrate. The acids are
Hydrogen salts. They have a sour taste,
and turn blue litmus paper red.
Adamantine. Diamond-like. A term
applied to the lustre of some minerals.
Actinolite. See Amphibole.
Adherent. A term applied to a few
minerals which absorb moisture so ra-
pidly as to adhere to the moist tongue.
Ex. Lithomarge.
Adularia. See Orthoclase.
A GA LMA TO LITE.
[Figure stone. Pagodite.] Amorphous,
massive, compact ; sectile, but easily
broken ; fracture splintery or flat con-
choidal ; opaque to translucent on thin
edges; dull; various shades of red,
green, yellow, grey, and brown ; unc-
tuous; streak white; H. 2-3; G. 2 '4-2 '9.
£'•, etc. In matrass gives off water;
on C alone turns white ; Fus. 5-6, the
white residue treated with Co turns blue ;
with borax forms a colourless bead ; in-
soluble in HC1 or HNO3 ; the powder is
decomposed by warm H2SO4.
< Comp. It is essentially an hydrated
silicate of alumina and potash. No
analysis of a British specimen is known
to the writer, but in four Chinese spe-
cimens the silica ranged from 64 50 to
56 '0 per cent., alumina from29'0to34'0,
peroxide of iron 0'5 to 1*25 ; lime 0 to
2-0, potash 5'25 to 7'0, water 3'0 to 5'0.
With silica 54 '2, alumina 31 '0, potash
9 '4, and water 5 '4, the formula may be
written K23Al29Si3H2 (when the oxygen
ratio will be as given by Dana —
1 : 9 : 18 : 3) or Si9O9Ko2(Al2o")3Ho3.
Loc. Restormel Koyal Iron Mines,
Lostwithiel, nearly white, or of a flesh
red tint. Also Wales, Ireland, Norway,
Germany, China, &c.
06s\ Agalmatolite is often much like
Steatite and Lithomarge, but it is harder
than Lithomarge and less lustrous ; and
differs from Steatite in the absence of
magnesia and the presence of potash.
The reaction with "Co" will distinguish
between Steatite and Agalmatolite, as
Steatite turns red, while Agalmatolite
turns blue. (See Blowpipe Keactions.)
Dana considers Agalmatolite to be a
variety of PinLe. The Kestormel
mineral has been named Agalmatolite
from its external characters alone.
Agate. Agate Jasper. See Calcedony.
Aggregate. A confused crystalline
AGNESITE.
Amorphous; massive, disseminate, in-
vesting; or in pseudomorphous acicular
crystals ; brittle ; fracture conchoidal ;
opaque to translucent on thin edges ; lus-
tre vitreous, glimmering, or dull; various
shades of green or yellow ; streak white
or greenish-white ; H. 4-4 '5; G. 6 '9-7.
£., etc. In matrass gives off a little
water, decrepitates, turns grey ; on O
alone melts easily, boils, and is reduced
to a grey brittle metallic bead, depositing
a dark yellow coating on the charcdal;
soluble with effervescence in HJNO3; the
ALBITE.
ALLOPHANE.
solution turns white on addition of a
large quantity of water.
Comp. It appears to be an impure
carbonate of bismuth, if the following
analysis of a specimen from St. Agnes
by Mr. Gregor be reliable : —
Carbonic anhydride 51 -3
Sesquioxide of bismuth 28 '8
Oxide of iron 21
Alumina 7'5
Silica 67
Water 3'6
Total 100-0
Thomson states (Min. II. , 594) that it
"does not elf ervesce with acids, and con-
tains only a trace of Bi." It may,
perhaps, be only an impure bismuth
ochre. The author has not been able to
procure a specimen for examination.
Loc. St. Agnes, at Huel Coates. A
similar mineral is said to have been found
at Botallack. It occurs also in Germany.
Alabaster. See Gypsum.
ALBITE.
[Soda Felspar.] Anorthic; with two
perfect cleavages, basal (O) and brachy-
diagonal (M), figs. 174, 175, and 182, form-
ing angles of 93° 36' and 86° 24'; in
variously modified prisms ; very often
macled ; also massive, lamellar, or com-
pact (Felsite); brittle; fracture uneven ;
transparent to opaque ; vi treous or pearly ;
white, sometimes tinged with yellow,
red, green, blue, grey; some specimens
shew a bluish opalescence, or a play of
colours on the basal cleavage. Streak
white ; H. 6-7; G. 2 "6-2 7.
Vir. Cleavelandite is a lamellar
white albite. Pericline occurs in large
opaque white crystals, which are often
short and broad. Compact albite or
albitic Felsite, usually contains disse-
minated grains of silica.
B., etc. In matrass unchanged ; on C
alone fuses at 4 to a colourless or white
glass, turning the flame intensely yellow.
It is not acted upon by HOI, HNO3, or
HS 804.
Comp. Albite is an anhydrous silicate
of alumina and soda, containing an ex-
cess of silica. The soda is often partially
replaced by potash and other bases. The
following is a recent analysis of a speci-
men from Trewavas, in Breage, by the
Kev. S. Haughton ;—
Silica 65-76
Alumina 21 72
Lime 0'89
Magnesia trace
Soda 9 23
Potash 176
Water 0'40
Total.
The range of composition in specimens
from other localities is considerable. The
silica varies from 65 "4 to 70 '0; alumina
181 to 21'9; oxide of iron 0 to 2 '3 ; lime
0 to 37 ; magnesia 0 to 1*5 ; soda 6'2 to
12'2 ; potash 0 to 6 '8. With silica 68 '6,
alumina 19 '6, and soda 11 '8, the formula
may be written AUNaSi (oxygen ratio
=1 :3 :12), or Si6O8Nao2Al2ovi.
Loc. Huel Friendship, Camelford, on
quartz ; Tintagel cliffs ; Delabole slate
quarries, in white crystals like Fig. 182,
with scheifer spar and quartz ; Tre-
wavas Head, Breage; and other localities
in the two counties. An interesting
specimen of albite, in very peculiar
colourless transparent twinned crystals,
was recently found at Huel Metal, in
Breage. in the 135 fathom level, by Capt.
G. M. Henty. It is now in the British
Museum.
Obs. The Eev. S. Haughton ob-
serves : -" The granites of Cornwall and
Devon, which have been frequently ex-
amined by me during the last sixteen
years, appear all to contain the two
felspars — albite and orthoclase." The
presence of albite is thought to be an
indication of the eruptive origin of the
granites in which it occurs. It is most
readily distinguished from orthoclase by
the inclination of its cleavages and the
intense yellow tinge which it imparts
the blowpipe flame. It is also more fus
ble than orthoclase, fusing at from 3 to
Angles.
MO = 93° 36' My = 149° 12>
MT 117 53 Og 29 55
O T 115 05 Ox 52 37
M f 148 30 y o 152 18
Mo 67 49 ox 152 41
OO 173 28
Alkaline. Having the properties
an alkali. The alkalies, potash, sod
ammonia, and lithia have an acric
caustic taste, and will turn yellow tu
meric paper brown, and reddened litmu
paper blue. Lime, baryta, strontia, an
magnesia possess the same properties i
a less marked degree, and are terme
alkaline earths.
Alliaceous. An odour resembling tha
of garlic (allium), which is given o
when minerals containing arsenic ar
heated on charcoal. Some give off th
odour on being broken.
ALLOPHANE.
Amorphous; mammillary, stalactitic
incrusting, or occasionally pulverulent
brittle ; fracture imperfect conchoidal o
earthy ; translucent to opaque; vitreou*j
ALLOY.
AMPHIBOLE.
resinous, or waxy ; shining or dull ; pale
sky blue ; sometimes colourless, or grey,
green, red, yellow, or brown ; streak
white; H. 3; G. I'S-IU
B. , etc. In matrass yields much water ;
on C alone crumbles to a white infusible
powder, which turns blue when treated
with Co ; decomposed by HC1, gelatinous
silica being deposited.
Cornp. It is an hydrous silicate of
alumina. No complete analysis of a spe-
cimen from the West of England is pub-
lished, but the composition generally
ranges from silica 17*0 to 241, alumina
29-2 to 41-0, lime 0 to T9, water 35 '2 to
44'2. With silica 221, alumina 38 '0,
and water 39 '9, the formula may be
written Al2Si6H2 (oxygen ratio = 3:2:6)
LOG. Garras Mine, near Truro, in
greyish translucent reniform masses,
very brittle. There is a fine specimen
from this locality in the Museum of the
Royal Institution of Cornwall at Truro,
and another in the Museum of Practical
Geology, Jermyn-street, London. Tavis-
tock (near) in beautiful pearly and trans-
lucent masses, some tinged blue or green,
with a little copper. Also Kent, France,
Belgium, Germany, United States, &c.
Obs. Schrotterite is, perhaps, only a
variety with less silica. Dana (System
of Min., 421, 1868) gives "Cornwall" as
a locality for schrotterite, but does not
say in what part. He may refer to the
mineral found at Garras Mine. The
composition of schrotterite ranges from
silica 10 '5 to 12 '0, alumina 46 '0, peroxide
of iron 0 to 2 '95, water 35 "5, to 41 '0,
which is nearly equal to 8Al23Si3H2.
Alloy. A combination of two or more
metals. "When mercury is one the alloy
is termed an amalgam.
Almandite. Almandine. See Garnet.
Alum. A name for a group of minerals
having a great similarity of composition
and properties ; all are very soluble, all
have more or less of the astringent taste
of common alum (Kaliuite); all are cubi-
cal ; sulphates ; and contain 24 equiva-
lents of water of crystallization; all have
the ratio of base and acid, and protoxide
to peroxide = 1:3.
Alum. See Kalinite.
^ Alumina is the sesquioxide of alumi-
nium, and is represented by the formula
AlgOs. In its pure state it is a white
powder, and when crystallized forms the
mineral corundum, which includes the
ruby, the sapphire, and emery. Many
minerals which contain alumina, if pow-
dered, heated on charcoal in OF, moist-
ened with a solution of nitrate of cobalt
(Co), and again heated, turn to a bright
blue colour. This reaction is successful
only in the absence of the oxides of iron,
manganese, and other heavy metals. If
after heating on charcoal without fluxes
there remains a white, or nearly white,
infusible mass, the experiment is likely
to be successful.
Amalgam. See Alloy.
Amethyst. See Quartz.
Amianthus. See Amphibole.
Amorphous. Without form. A term
applied to minerals which are not known
to crystallize.
AMPHIBOLE.
[Hornblende; &c.] Oblique, in prisms,
usually modified, often macled, the faces
often curved, or striated, or uneven ;
cleavage perfect, prismatic ; parallel to
M. (Fig. 181); the angles formed by the
cleavages are 124° 30' and 55° 30' ; in ag-
gregates of long thin prisms ; or massive,
nbrous, divergent, reticulate ; granular,
disseminate, or compact ; tough, brittle,
or flexible ; fracture imperfect conchoi-
dal, uneven, or splintery ; translucent to
opaque ; vitreous, pearly, glimmering,
or dull ; sometimes white, but more usu-
ally green, of various shades; or grey,
yellow, brown, or black; streak white or
slightly brownish ; H. 5 to 6 (except
asbestos and amianthus, which are soft):
G. 2-9-3-4.
Var. 1. Hornblende. Short thick
prisms, or massive ; usually dark green
or almost black ; tough.
2. Actinolite, long prismatic aggre-
gates, often divergent or radiate; brit-
tle ; usually some dark shade of green.
3. Tremolite, white, grey, or light
green bladed crystals, with a pearly
lustre, containing much MgO and CaO,
and some FeO, with but little A12O3.
4. Asbestos, Amianthus, &c. Gener-
ally white, and in fine soft flexible fibres,
that are easily separated.
5. Mountain Paper, Mountain Cork,
Mountain Wood, &c., in brown felted
masses, that will sometimes float on
water until finely powdered.
6. Amphibolyte or hornblende rock is
massive, dark green or black, with a
granular texture. Hornblende schist is
similar, but has a slaty structure. Both
often contain some albite.
J?., etc. In matrass usually unchanged,
but sometimes yields a little water ; on
C alone fuses at from 3 to 4, according
to the amount of iron present, to a grey,
green, or black bead, the darker ones
mostly magnetic; with soda forms a
fusible slag; with borax or micro.
AMPHIBOLE.
AMPHIBOLE.
generally gives Fe reactions: insoluble
in HC1 or HNO3.
Comp. Tremolite is a silicate of mag-
nesia and lime ; actinolite and asbestos
of magnesia, iron, and lime ; hornblende
of alumina, magnesia, iron, and lime. Of
the following analyses a. is a " tremo-
1:t~" from Clicker Tor, analysed by the
from Huel Unity, analysed by Thomson,
in which the iron is partly replaced by
manganese: sp. gr. 2'91 (Ann. Phil.
1814):-
a. b.
Silica 62-2 33-40
Alumina — 28-20
Oxide of iron 5'9
Oxide of manganese . . trace
Lime 14-1
Magnesia 12-9
Soda trace
Oxide of copper —
Water 1-0
Loss 3-9
1715
7'20
1-05
3-80
1-03
1-70
5-90
Loc. 1. Hornblende— Botallack, Cape
Cornwall, and many other parts of St.
Just ; Marazion Mines, Acton Castle,
Cuddan Point, and many parts of the
Mount's Bay coast ; Goonhilly Downs,
Mullion, Kynance, Coverack, Cadgwith,
and other paits of the Lizard district ;
West Godolphin Mine, Breage : West
Rev. Wm. Gregor (Ann. Phil., 2, 1813, Poldice Mine, St. Ives ; Great Dowgas
p. 154); b. is an "asbestos actinolite" i Mine, St. Stephens; Camborne Vean
Dolcoath, Huel Crofty, and other Cam-
borne mines; Tresavean Mine; Penmare
Point, Veryan ; Five Lanes, Launceston.
Hay Tor, Brent Tor, Bovey Tracey,
and other places in Devon ; but seldom
in well-formed crystals.
2. Actinolite— At most of the above
localities, and at North Roskear Mine,
Camborne ; in greenstone, between East
Huel Crofty and Pool ; Trevascus Mine ;
St. Ives Consols, Huel Unity, Gwinear;
the Consolidated Mines, Gwennap, at
320 fathoms from surface ; Charlestown
United Mines and Duforth Mine, St.
Austell; Great Retallack Mine Perran-
zabuloe ; Maudlin Mines ; St. Cleer ;
Cheesewring and Clickor Tor, near Lis-
keard ; Delabole Slate Quarries, in dark
green foliated masses ; Fowey Consols,
in quartz.
Seaton, Sticklepath, near Okehamp-
ton, &c.
3. Tremolite— St. Just, Lizard, and St.
Cleer ; in the abovementioned localities;
and at East Huel Crofty.
4. Asbestos, Amianthus, Mountain
Wood, Mountain Paper, Mountain Lea-
ther, &c. — At most of the above localities ;
at St. Veep, of a dull white colour ; and
at Axmouth, Seaton, and Sidmouth, in
Devon.
Foreign localities of all the varieties
are very numerous.
Ob*. Many of the "greenstones" of
the^West of Cornwall, especially about
Gwinear and Marazion, cousist of nearly
pure hornblende, or of hornblende inti-
mately mixed with felspar. Some of them
Total 100-0 100-00
The range of composition in foreign
varieties is very great. In Actinolite,
Asbestos, &c., the silica ranges from 55 '0
to 60'0 per cent., alumina 0 to 3 '2; oxide
of iron 3'0 to 12 '0, oxide of manganese 0
to 1-2 ; magnesia 9'5 to 24*0, lime 9*5 to
21 '0, water 0 to 3 '6. In Tremolite, silica
57 '3 to 60'6, alumina 0 to 1 8, oxide of
iron 0 to 2 '4, magnesia 24'0 to 28 2, lime
ll'O to 151, water 0 to 3 '3. Hornblende,
silica 37 '0 to 55 '0, alumina 4 "5 to 17 '6
peroxide of iron 0 to 10 '2, protoxide of
iron 5'8 to 29'3, oxide of manganese Oto
3'5, magnesia 5'0 to 21 '0, lime 4 '6 to
15-0, water Oto 2U
With silica 57 '6, magnesia 28*8, lime
13 '6, the formula for Tremolite may be
Ca 3Mg 4Si (oxygen ratio for bases and
silica 1 to 2) or Si4O4Mgo"3Cao".
With silica 53 '6, magnesia 18 '0, oxide
of iron 16 '0, lime 12 '5, the formula for
Actinolite may be CaFe2Mg4Si (oxygen
ratio = 1 to 2) or Si4O4 Mgo"2Feo"Cao".
With silica 531 alumina 11 '3, oxide of
iron 15 '9, magnesia 13*2, lime 6 '5, the
formula for Hornblende may be
Ca2Fe3MgAl28Si (oxygen ratio for prot-
oxides, peroxides, and silica = 6 : 3 : 16)
or Si8O7Al2oviMgo"3Feo"2Cao".
06s. Tremolite usually occurs asso-
ciated with limestones, particularly those
that contain magnesia. Actinolite is
associated sometimes with steatite ; the
asbestiform variety with serpentine ;
Hornblende with mica schist, chlorite
•chist, and gneiss.
contain minute grains of magnetite dis-
seminated through them, which, if the
rock be finely powdered, may be separated
by the magnet. Like most of the ferrugi-
nous hornblendes, they are very liable to
decomposition, thus forming some of the
richest soils of the county.
Amphibole and Pyroxene are very
closely-related species, if, indeed, they
should not rather be viewed as one.
Dana remarks that "it is impossible to
distinguish them by blowpipe characters
alone." The range of chemical composi-
tion is so great as to render a chemical
division in the highest degree artificial
Crystals of amphiboleand pyroxene differ
AMYGDALOID.
ANATASE.
strikingly in habit and in modifications,
but it is quite possible to refer all these
modifications to the same system of axes.
Twins have been found composed part of
amphibole and part of pyroxene. The
sp. gr. of hornblende is, however, usually
a little less than that of pyroxene, and
hornblende mostly occurs in. rocks con-
taining quartz or free silica, and ortho-
clase or albite, while pyroxene occurs in
rocks containing little or no free silica,
and with such minerals as labradorite,
olivine, and leucite.
It seems not unlikelv that hypersthene
also might be included in one species with
amphibole and pyroxene. Hypersthene
is sometimes made to include bronzite,
but Dana includes some infusible bron-
zites with amphibole, and the fusible
varieties with augite.
Much of the so-called asbestos is chry-
sotile, or fibrous serpentine. It may be
distinguished from the true asbestos by
giving off a large quantity (12 to 14 per
cent.) of water, on heating in a matrass.
Angles.
M M' = 124° 30' b r = 105° 46'
MO 103 12 rr' 148 oO
Mb 117 45
Amygdaloid. A rock of a vesicular
structure, the cavities being occupied
with different materials. When these
are light coloured, as is usually the
case, and the rock is dark, the whole
presents an appearance something like
almonds in a cake. Hence the name,
from a Greek word signifying an almond.
Such rocks are common in the Hebrides,
the Giant's Causeway, and in many vol-
canic regions. Many of them seem to
have been originally vesicular lavas,
through which water charged with cal-
careous and siliceous matter has perco-
lated, and gradually filled up the cavities
with agates, spars, zeolites, &c. Some
of the cliffs near the Botallack Mine exhi-
bit an imperfect amygdaloidal structure.
ANAL CITE.
[Analcime. Kubizite.] Cubical, usually
in deltohedrons, like Fig. 5, but some-
times a combination of the cube and
deltohedron (Fig. 19); also massive,
fibrous, or radiating ; brittle ; imperfect
conchoidal or uneven fracture ; trans-
parent to opaque ; vitreous or pearly ;
white, or various shades of grey, green,
yellow, red ; streak white , H. 5 to 5'5 ;
G. 2 to 2 '3 ; feebly frictio-electric.
B., etc. In matrass gives off water, and
turns white ; on C alone turns white,
and fuses at 2 '5 to a clear glass ; readily
decomposed by HC1, depositing gela-
tinous silica.
Comp. Analcite is an hydrated silicate
of alumina and soda. Its range of com-
position is silica 51 '0 to 56 '2, alumina
22-2 to 24-2, lime 0 to 5'8, soda 6'5 to
14 '6, potash 0 to 4 '6, water 7 '6 to 97.
With silica 54 '6, alumina 23 '3, soda 141,
water 8 '2, the formula may be written
Na2Al24SiH2 (oxygen ratio for protoxides,
peroxides, silica, and water 1 : 3 : 8 : 2, or,
counting the water basic 3:3:8), or
Loc. It is said to have been found in
cavities of the cliffs near Botallack, but
the author has never seen a Cornish
specimen ; the mention of it may, how-
ever, lead to its discovery in this nofc
unlikely locality. It is found in Scot-
laud, Ireland, Faroe, Iceland, Norway,
Germany, Italy, United States, &c.
Obs. Analcite is usually found in
amygdaloids, or in rocks of volcanic
origin, in forms resembling Figs. 5 and 19.
Angles.
a a = 90° 00' nn = 146° 27
an 144 44 n n' 131 49
Analysis. The separation of the con-
stituent parts of a compound. The
statement of the result of the process is
often spoken of as the analysis. The
person by whom the work is done is
called the analyst.
ANATASE.
[Octahedrite.] Pyramidal ; in small
crystals, like Figs. 72, 73, and 234, with
perfect cleavages parallel to P. and O.
from P. to P. = 97° 51', P. to O. =
111° 42' ; brittle ; sub- conchoidal or un-
even fracture ; semitransparent to
opaque ; lustre adamantine or sub metal-
lic, usually brilliant ; brown to deep blue
by reflected light, greenish-yellow by
transmitted light ; streak white or slight-
ly coloured; H. 5 '5-6 ; G. 3 "8-4, after
heating 41 to 416; frictio-electric.
B., etc. In matrass unchanged or
phosphorescent ; on C infusible ; with
soda melts to a dull yellow globule, white
on cooling; with micro. OF forms a
clear bead, which is yellow while hot,
violet when cold ; if iron is present the
bead may be brownish, but will be ren-
dered violet by the addition of a small
fragment of tinfoil; soluble in concen-
trated H2SO4, but not in HC1 or HNO3.
Comp. Titanic anhydride. Ti or TiOa ;
Oxygen 7971, Titanium 60 '29.
Lor. Looe Mills Hill Quarry, near
Liskeard; Tintagel Cliffs; Delabole Slate
Quarries ; Virtuous Lady Mine, in chlo-
rite, in crystals, like Figs. 72 and 73,
which vary in size from one-sixth of an
inch downwards to microscopic crystals.
ANDALUSITE.
ANNABEEGITE.
Angles.
P P = 97° 51' e e = 116° 43'
PP' 136 30 ee' 121 16
PO 111 42 11 159 26
Ov 160 15 cl 139 50
ANDALUSITE.
[Chiastolite. Made.] Rhombic. Usually
in four-sided prisms, like Figs. 94,
and 95 ; also massive, with a lamellar
structure ; tough ; fracture even or un-
even ; translucent to opaque ; lustre
vitreous or pearly, but often dull ; white,
or tinged with violet, grey, red, green,
brown; streak white; H. 7-7 '5, ex-
cept when partially decomposed, when
it may be as low as 3 ; G. 2 9-3 '4.
Var. Chiastolite is a variety occur-
ring in square prisms, which appear to
be made up each of four crystals, having
prisms of a darker colour in the centre
and at each angle, connected by thin
plates of the same, like Fig. 94. The
colour of the dark portion may often be
destroyed by heating.
B., etc. In matrass unchanged ; on C
inf us/ble ; the powder moistened with Co
and again heated becomes blue ; with
borax fuses with difficulty to a trans-
parent colourless glass ; with soda swells
up, but does not fuse ; insoluble in acids,
but some varieties are decomposed by
HC1, leaving a mass of gelatinous silica.
Comp. Anhydrous silicate of alumina,
but usually contains some peroxide of Fe
and oxides of Mn, Mg, and Ca. The fol-
lowing range of composition has been
indicated by various analyses of foreign
specimens, viz.:— Silica 33'0to4017;
alumina 50 '96 to 62 '20 ; peroxide of iron
0 to 5 71 ; oxide of manganese 0 to 0'83 ;
magnesia 0 to 114; lime 0 to 412;
water 0 to 2 '6. With silica 36 '8, and
alumina 63 '2, its formula might be AL>Si
(in which case the oxygen ratio = 3 f 2)
or SiO(Al204)".
LOG. "Andalusite, in attached and
imbedded crystals, is said to occur on
Dartmoor, and also in the neighbourhood
of Okehampton. Chiastolite is found in
small crystals penetrating an altered
Devonian slate at Ivybridge, and also
associated with axinite at Holestock,
near Okehampton." (Report of Devon
Assoc. 1868, p. 341.) Also Cumberland,
Scotland, Ireland, Brittany, Spain,
United States, &c.
Obs. Chiastolite may be distinguished
from felspar by the black cross seen in
the cross section of the crystal; andalu-
site by its superior hardness and ex-
treme infusibility. The surfaces of the
crystals are often rough, or covered with
flakes of mica. In some instances the
whole crystal has been converted into
mica.
Angles.
M M = 90° 44' M O = 90° QV
O s 144 55
Angle. See Crystallography.
ANGLESITE.
Rhombic, often in tabular or prismatic
j crystals, like Figs. 127, 128, 129, 130,
: 132, with cleavages parallel to M. and
; O., but not perfect ; or drusy ; also sta-
| lactitic or massive ; brittle ; fracture
i conchoidal ; transparent, to translucent
i on edges only ; adamantine, vitreous, or
| resinous ; white, sometimes tinged grey,
j yellow, green, blue, brown; sometimes
i black on the surface ; streak white ; H.
3 ; G. 61-6-4.
B., etc. In matrass decrepitates and
i darkens ; often yields a little water with
acid reaction ; on C fuses at I'o to a
' globule which is clear while hot, but milk
! white on cooling ; in RF is easily reduced
I to a bead of Pb ; with soda and silica gives
i the reaction for sulphur ; almost insolu-
| ble in acids, but the powder is com-
pletely soluble in KHO.
Comp. Sulphate of lead, PbS, or
PbSO4, or SO;2Pbo".; oxide of lead
73'61 ; sulphuric anhydride 26 '39.
LOG. Mellanoweth, near Hayle; for-
merly in gossan at Huel Maggot ; Huel
Bell, St. Erth; Huel Rose and Huel
Penrose, near Helston ; West Huel Chi-
verton ; Pendogget, Liskeard ; Beeral-
stone ; East Tamar Mine ; Beerferris, in
geodes of decomposed galena, the faces
M. and z. predominating. Fig. 132 is a
Cornish form. Also Cumberland, Derby-
shire^ Anglesea, Scotland, Germany,
Siberia, United States, &c.
Obs. Anglesite usually occurs with
galena, pyromorphite, cerussite, and
other ores of lead. It is not a common
mineral in the West of England.
Angles.
O M = 90° W d d' 78° 45'
Ob 90 00 zz' 89 41
MM' 103 38 oo' 75 39
Oo 127 45 LI 135 20
Od 140 38 dd 101 15
Anhydrous. Without water. Minerals
which do not yield water, even when
strongly heated, in a closed tube before
the blowpipe, are said to be anhydrous.
Anhydrous Binoxide of Manganese.
See Pyrolusite.
ANNABERGITE.
[Nickel green. Nickel ochre.] Oblique ;
in minute capillary crystals, as a flaky
efflorescence ; massive ; disseminated j
friable or sectile ; dull or glimmering ; va-
rious shades of green ; streak light green
ANOKTHIC.
ANTIMONY.
or white, shining; H. 2-2'5; G. 3-3'2.
U., etc. In matrass yields water and
darkens ; on C melts readily, giving off
fumes with a strong garlic odour, and
coating the charcoal white at a little dis-
tance from the assay ; in RF yields a
white brittle bead of metallic appear-
ance ; with borax OF a bead which is
often violet while warm, and reddish-
brown when cold ; RF the bead becomes
colourless or greyish ; soluble in HC1 or
HNO3, forming a green solution.
Comp. It is an hydrous arseniate of
nickel. No analysis of a British speci-
men is known to the author. The aver-
age composition of foreign specimens
analysed approaches to arsenic anhy-
dride 38'6, oxide of nickel 37 '2, water
24 '2, which would agree with the follow-
ing formula :— 3NiAs2 + 8H3 or As2O2
Nio"3 + 8OH2.
Lac. Pengelley Mine and Huel Chance,
Si. Ewe; St. Austell Consols; Huel
Jane, St Kea, on kupfernickel (Nicco-
lite). Also France, Germany, Canada,
United States, &c.
Obs. From its occurrence on the sur-
face of other nickel ores containing
arsenic, it is probably a product of their
decomposition.
Anorthic. See Crystallography.
Anthracite. See Coal.
Antimonial Ochre. See Cervantite
and Stibiconite.
Antimonial Silver Blende. See Py-
rargyrite.
Antimonial Sulphide of Iron. See
Berthierite.
Antimoniate of Lead. See Bleinierite.
ANTIMONITE.
[Antimony Glance.] Rhombic ; Fig.
97; usually in laterally aggregated
prisms, with one perfect (brachydiagonal)
cleavage; which truncates MM'; diver-
gent or radiating ; the cleavage planes
often striated ; also massive, with colum-
nar structure ; or fibrous, plumose,
woolly, or felt-like ; sometimes dissemi-
nated, brittle, or sectile ; thin laminaa
slightly flexible and malleable ; fracture
sub-conchoiual, but rarely obtained;
opaque ; metallic ; steel-grey to lead-
grey ; streak black ; H. 2 ; G. 4 '5-4 7.
B . etc. In matrass gives a yellow or
reddish sublimate but no water ; on C
fuses at 1, and burns with a greenish
flame, depositing a white coating near the
assay; entirely volatile, except some-
times a very little infusible slag, which
gives Fe reactions ; soluble in warm HC1,
giving off H2S ; decomposed by HNOs,
leaving a white powder of oxide of anti-
mony; decomposed by KHO, the solu-
tion yielding a yellowish flaky ppt. on
adding HC1.
Comp. Anhydrous sulphide of anti-
mony.
a. b.
Sulphur 74-0 74'06
Antimony 26'0 25'94
Total lOO'O 100-00
a. by Bergmann, b. by Davy. Both spe-
cimens Cornish. "With 72 "88 per cent,
of antimony and 27'12 of sulphur the
formula will be Sb2S3.
LOG. Huel Boys, Endellion (Fig. 97),
and plumose ; Padstow and Tintagel, in
N. and S. veins, in fibrous masses ; Old
Trewetha ; Pendogget and Port Isaac
(plumose), St. Merryn ; Huel Lee, St.
Minver ; Pillaton, St. Stephens ; Fowey
Consols ; Restronguet, near Devoran ;
Hennock ; Bovey Tracey ; Combemartin,
in small quantities, with argentiferous
galena, both fibrous and in acicular crys-
tals. Also Cumberland, Scotland, France,
Spain, Germany, Hungary, Italy, Borneo,
N. America, S. America, &c.
Obs. It is the chief ore of antimony.
It may be distinguished from jameso-
nite, which it often much resembles, by
the absence of a basal cleavage, and its
almost complete solubility in HC1 ; from
pyrolusite, graphite, and molybdenite,
by its fusibility. It is isomorphous with
bismuthite.
A ngles.
M M' = 89° 15' M M = 90° 45'
Mb 134 37 p'p 109 16
Mp 145 29 pb 125 22
ANTIMONY.
Hexagonal, sometimes in rhombohe-
drons, with perfect basal cleavage, like
Fig. 221 ; sometimes striated, usually
reniform, spherical, or massive; lamellar
or granular ; brittle ; opaque ; metallic ;
tin-white, with a greyish tarnish ; streak
like the colour; H. 3-3 '5; G. 6 '6-6 '8.
/?., etc. In matrass melts and gives a
slight white sublimate when strongly
heated ; on C fuses readily and burns
with a greenish flame, depositing a white
coating on the charcoal near the assay,
which tinges the flame greenish if
directed upon it ; sometimes a slight
garlic odour ; a melted bead crystallizes
on cooling ; may be entirely volatilized,
except a very little infusible slag, which
will give iron reactions ; soluble in Aqua
Reg^a.
Comp. Antimony, with usually a
little iron, arsenic, silver, or other im-
purity. No analysis of a Cornish speci-
men is on record.
Loc. It is said to have been found in
ANTIMONY.
APATITE.
the antimony mines near Padstow ; also
France, Germany, Sweden, Borneo,
Canada, United States Mexico, Chili, &c.
Antimony. All minerals containing
antimony when heated on charcoal de-
posit a white coating on the cool part of
the support, no garlic odour being ob-
servable unless arsenic be present, which,
however, is often the case. When lead,
bismuth, cadmium, zinc, or silver are pre-
sent the coating is liable to be obscured.
In such cases there are no simple and
generally applicable blowpipe tests.
Antimony Glance. See Antimonite.
APATITE.
Hexagonal ; in six-sided prisms ; often
vertically striated and variously modi-
fied, like Figs. 189, 190, 191, 196 ; also
massive, earthy, or fibrous ; brittle ;
fracture conchoidal, uneven, or splin-
tery ; transparent to opaque ; vitreous
or resinous ; brilliant to dull ; white, or
various shades of yellow, blue, green,
brown, red ; sometimes parti-coloured
or dichroic ; some crystals show a bluish
opalescence when viewed in the direction
of the principal axis ; streak white ; H.
4 '5-5; G. 3 "Z-3 '3; sometimes pyro or
frictio-phosphoric.
Var. Francolite is a name which has
been given to specimens occurring in
small compound crystalline masses,
sometimes greyish, greenish, or brown-
ish ; in minute white transparent crys-
tals with Curved faces, somewhat like
Fig. 189, but with deep and uneven
longitudinal striations ; in thin plates
with quartz and chalcopyrite, and in
thin, hollow, pseudomorphous cubes of
an inch or more, which, when first dis-
covered arehalf f ullof atransparentfluid.
B.t etc,. In matrass unchanged ; if
mixed with micro, usually gives off HF ;
on C fuses at 4-4*5— some varieties infusi-
ble ; with borax melts to a clear globule,
which may be rendered opaque by
" flaming;" soluble very freely in micro.,
affording a glass which is usually trans-
parent while hot, but if saturated,
opaque and crystalline on cooling ; the
powder moistened with H2SO4 and
heated tinges the flame bluish-green ;
soluble in HC1 or HNO3 without effer-
vescence ; when warmed with HgSO^gives
off a gas (HF) which turns Brazil wood
paper yellow if fluorine be present.
Comp. It is a phosphate of calcium,
usually containing fluorine and chlorine.
The variety called francolite contains
only a trace of chlorine, as appears from
the accompanying analyses. Foreign
varieties of apatite contain from 0 to 41
per cent, of chlorine, and from 0 to 4 '2
per cent, of fluorine.
Analyses ; both by T. H. Henry, from
Huel Franco (Francolite): —
a. b.
Phosphoric anhydride 41 '34 41 '80
Lime 53'38 52'81
Fluorine and loss 2'32 217
Chlorine trace trace
Oxides of iron and
Manganese 2'96 3'22
Total ............... 100-00 100-00
With phosphoric anhydride 42 '2, lime
54 '0, and fluorine 3 '8, the formula for
Fluorapatite (Francolite) may be written
9Ca3P2 + CaF2 or P.sOgCao'^CaFO. With
phosphoric anhydride 40 9, lime 52 '3,
and chlorine 6 '8, the formula for Chlor-
apatite (Apatite) will be 9Ca3P2 -i- CaClj
or P3O3Cao"4CaClO.
The composition of a specimen lately
analysed by Professor Maskelyne and
Dr. Flight agreed with the following
formula, viz., 5([3Ca2PO4]CaCo3) -!- 2Ca
F2; or a fluorapatite, in which one
part of the calcium phosphate is replaced
by calcium carbonate. Its crystalline
form differs somewhat from ordinary
apatite.
Loc. The rocks north of Botallack,
in white or yellowish-green crystals,
i with hornblende, axinite, magnetite,
garnet, &c. ; Botallack Mine ; Huel
Owles: St. Michael's Mount, like Fig.
196, with topaz, tourmaline, cassiterite,
&c.; Godolphin Bridge Mine and Tre-
mearne (with gilbertite), in brilliant and
highly modified transparent bluish,
greenish, or greyish crystals, in granite ;
Huel Kind, St. Agnes, on quartz, in
small greenish crystals, with calcite,
some like Fig, 189 ; St. Kea ; Poldice,
in hexagonal tables ; Stenna Gwynn,
greyish-blue in gilbertite ; Fowey Consols
and Huel Franco (Francolite) ; St.
Stephens; Crinnis.
Bovey Heathfield ; Chudleigh ; near Bo-
vey Tracey, cream coloured, in a quarry,
Figs. 189 and 191. These crystals were
sometimes two inches long, associated
with pure tourmaline. This locality is
exhausted, but other specimens may,
perhaps, be found in the neighbourhood.
Also Cumberland, Norway, Germany,
Italy, United States, Scotland, Ire-
land.
Obs. Apatite is usually found in
crystalline or schistose rocks, associated
with tin and iron ores or with serpentine.
In Cornwall and Devon it mostly occurs
in granite, with tourmaline, cassiterite,
and gilbertite.
ABAGONITE.
ARSENIC.
A ngles.
ab
r o
io
120°
150
90
124
157
139
00'
00
00
20
05
47
z o
X X
r r
u a
r a
u o
120°
142
131
149
135
110
36'
20
14
38
39
03
Aqua Regia. A mixture of HC1 with
HNC>3 ; so called because it will dis-
solve gold the " King" of inetals.
ARAGuNITE.
Rhombic, usually in acicular crystals,
or hexagonal prisms (macles), with one
distinct and two indistinct cleavages,
forming angles of 121° 55', 116° 10', and
125° 47' ; also in globular concretions ;
or reniform, dendritic, or coralloid ag-
drusy and investing ;
England, Scotland, Ireland, Spain, Ger-
many, Hungary, Italy, United States, &c.
Obs. Aragonite is a little harder and
a little heavier than calcite, which has
the same composition, its cleavages are
less distinct, and do not produce rhom-
bohedrons as do those of calcite ; it falls
to pieces when heated in a matrass, in
this also differing from calcite.
Arborescent. Branched like a tree.
"Dendritic" is sometimes used in the
same sense. Native Silver is often
arborescent.
Arenaceous. Sandy.
Argentiferous. Containing silver.
ARGENT IT E.
[ Yitreous Silver. Silver Glan ce. ] Cubic ;
ia cubes, octahedrons, and rhombic do-
decahedrons, or deltohedrons, more or
gregations; or o ,
sometimes in fibrous or compact masses ; I less modified (Figs. 1,2,3,5,8, 19,20,&c.);
brittle ; fracture conchoidal or uneven ; ! also reticulated, arborescent, stalactitic,
transparent to opaque ; vitreous, resi- i amorphous, earthy, or disseminated ;
nous on fracture, silky if fibrous; white, I sectile, often somewhat flexible or mal-
or tinged with grey, yellow, red, blue, ' leable ; fracture hackly, uneven, or
earthy ; opaque ; lustre metallic, often
dull ; lead grey to black ; sometimes
iridescent ; streak dark and shining :
H. 2-2-5; G. 6 '9-7 '4.
Var. Black sulphuret of silver, silver
green, brown ; streak white, or much
lighter than the colour; H. 3 '5-4; G.
2 7 to 3.
Var. Flosferri is the name given to
coralloid varieties, satin spar to a fibrous
variety.
B. , etc. In matrass swells and falls to
powder, evolving a very little water ;' on
C infusible, but incandesces and be-
comes alkaline ; when Sr is present,
mulm or silver black is an impure earthy
variety.
£., etc. In matrass gives a yellowish
sublimate of S j on C fuses at 1, and is
easily reduced to a white malleable bead
which is often the case, the flame will of Ag, giving off a sulphurous odour ;
be tinged carmine red, especially after j insoluble in HC1 ; readily soluble, ex-
being moistened with HC1 ; if no Sr, cept a little sulphur, in hot concentrated
then the flame will be brick red. Soluble
with effervescence in dilute HC1 or
HN03.
Comp. It is an anhydrous calcic car-
bonate, but appears usually to contain a
little Sr, Fe and H2O as impurities.
With carbonic anhydride 43 '71, and
lime 56 '29, the formula will be Ca C or
COCao".
LOG. It is said to occur at Botallack
and Huel Owles in white, grey, red, or
bluish-green globular concretions, or in-
crustations, or druses, acicular and
fibrous, on quaitz and chalybite. Many
of these are certainly calcite. Huel
Edward, with chrysocolla ; Levant, St.
Erth, in fine macled hexagonal crystals,
and in coralloid forms (flosferri); Huel
Edward, Calstock ; Mawnan cliffs, near
Fal mouth ; Port Isaac and Tintagel
cliffs, coralloidal, white, greyish, or
pinkish ; Buckfastleigh ; Combemartin
(flosferri); Ilfracombe and Torbay, in
beautiful acicular crystals and fibrous
masses, in thin veins traversing slate ;
also Cumberland and other parts of
HNO>
Comp. Anhydrous argentous sul-
phide, as appears from the analyses of
foreign specimens, which yield from
77 '6 to 85*3 per cent, of silver, with
about 15 per cent, of sulphur, and
usually some small proportion of Pb,
Cu, and Fe. No analysis of a British
specimen is published. With silver
87 '05, and sulphur 12 '95, the formula is
Ag2S or SAg2.
Loc. Huel Herland, in well-defined
crystals (Figs. 8 and 15) and massive ; Huel
Ann, Phiilack; Huel St. Vincent;
Huel Brothers; Huel Duchy (earthy);
Huel Mexico ; Huel Basset ; South Huel
Basset ; North Dolcoath ; Dolcoath ;
Mount Mine, Perranuthnoe, and some
other mines in Cornwall, both massive
and earthy. Also Scotland, France,
Spain, Hungary, Italy, Germany, Nor-
way, Siberia, Mexico, Peru, &c.
A ngles.
00 = 109°
a a 90
oa 125
dd 120
28'
00
16
00
n n
n n'
an
ad
= 146° 27'
131 49
144 44
135 00
10
ARSENIC,
ARSENOLITK
Argillaceous. Clayey.
Arragonite. Arragon Spar. Se« Ara-
gonite.
ARSENIC.
[Native Arsenic.] Hexagonal; some-
times in rhombs with perfect basal cleav-
age, like Fig. 221, but usually reniform,
stalactitic, mammillary, or reticulate;
also massive ; compact, with a curved
amellar structure, granular, or dissemi-
nated ; fracture uneven or fine granular ;
opaque ; lustre metallic, often dull ;
whitish, lead grey on fresh fracture, but
usually a dark tarnish on the surface ;
streak grey ; shining ; H. 3'5 ; G. 5 '9-6 ;
when broken gives off an odour re-
•embling that of garlic.
B., etc. In matrass a dark metallic
•ublimate when strongly heated ; in open
tube a white crystalline sublimate ; on
C volatilizes in dense white fumes with-
out fusing, burning with a blue flame and
strong alliaceous odour, and depositing a
white coating on the cool part of the
charcoal. It usually leaves a minute resi-
due, which contains Fe, and sometimes
Au, Ag, Co. Soluble in HC1.
Comp. Arsenic, with generally small
portions of other metals. No analysis
of a British specimen is recorded, but
foreign specimens yield from 96 to 99
per cent, of As.
Loc. It is said to have been found at
Dolcoath and Cook's Kitchen, with ores
•f tin and cobalt ; also Norway, Ger-
many, France, Siberia, Chili, United
States, &c. , generally in veins traversing
altered slaty rocks.
Obs. Arsenic may always be detected
in a mineral by the white crystalline
sublimate which is formed when the
assay is heated in an open tube, and the
odour resembling garlic which is evolved
when it is heated on charcoal in R F.
Arseniate. A compound of arsenic
anhydride, with a metallic oxide ; or ar-
senic acid in which the hydrogen has
been replaced by a metal. Arsenic may
be detected in arseniates, arsenides, or
alloys, by the white incrustation depo-
sited on charcoal far from the assay, and
the strong alliaceous odour produced
when this is treated with the reducing
flame. The following arseniates occur
in the two counties, each of which is
described in its proper place : —
Olivenite, Pharmacosiderite,
Liroconite, Pitticite,
Clinoclase, Scorodite,
Erinite, Annabergite,
Cornwallite, Erythrite,
Chenevixite, Bayldotdte,
Ckalcophyllite, Mimetite.
In many of these the arsenic is partially
replaced by phosphorous. All are hydrous
except mimetite.
Arseniate of Cobalt. See Erythrine.
Arseniate of Copper. See Olivenite,
Clinoclase, Liroconite, Chalcophyllite,
Cornwallite, Erinite, Chenevixite.
Arseniate of Iron. See Pharmacosi-
derite, Pitticite, and Scorodite.
Arseniate of Lead. See Mimetite.
Arsenic Bloom. Arsenic Oxide. See
Arsenolite.
Arsenic Silver. "A mixture of mia-
plckel and discrasite, found formerly at
North Dolcoath in masses with a con-
centric lamellar structure, alternating
with quartz, the whole bearing some re-
semblance to agate."
Arsenical Cobalt. See Smaltite and
Cobaltite.
Arsenical Iron. Arsenical Mundic.
Arsenical Pyrites. See Mispickel.
Arsenical Nickel. See Niccolite and
Smaltite (Chloanthite).
Arsenide. A compound of arsenic
with some other metal or metals. Arse-
nides differ from arseniates in the ab-
sence of oxygen. They are much like
sulphides in their physical properties.
The arsenides found in the two counties
are Niccolite, Smaltite, Cobaltite, Leu-
copyrite (?). Miapickel is a sulpharsenide.
ARSENOLITE.
[Arsenious acid, Arsenious anhydride.]
Cubical ; sometimes in octahedrons with
octahedral cleavage, but usually capil-
lary, flaky, pulverulent, stalactitic, bo-
tryoidal, or investing ; brittle ; trans-
lucent to opaque; vitreous, adamantine,
silky, or pearly ; often dull ; white, or
reddish, yellowish, brownish ; streak
white; H. 1-1 '5; G. 3-6-37; taste sweet-
ish and astringent ; highly poisonous.
B., etc. In matrass altogether volatile,
forming a white crystalline sublimate ; on
C is partly reduced at first to a grey brittle
metallic bead, which may be volatilized
in dense white fumes by continuing th«
blast ; gives a strong alliaceous odour ;
deposits a white coating at some distance
from the assay ; slightly soluble in
water, more so if the water be warmed ;
soluble in HC1, the solution deposits a
grey metallic coating on clean copper.
Comp. Arseniousl anhydride. Asj
O3 ; it often contains a little sulphur.
When pure its composition is— Arsenic
7576, oxygen 24 '24.
Loc. Huel Sparnon and some other
mines, in acicular crystals, filling cavi-
ties in smaltite ; sometimes investing
smaltite and cobaltite. Also Germany,
Transylvania, Spain, California, &o.
ASBESTOS.
AUTUNITE.
11
Asbestos. See Amphibole.
ASBOLANE.
[Earthy cobalt.] Amorphous; massive,
earthy, pulverulent, or incrusting ; sec-
tile, almost malleable ; opaque ; resinous,
glimmering, or dull ; bluish and brown-
ish-black ; streak black, shining ; H. '5
to 1'5; G. 2 to 2'2.
B., etc. In matrass yields water; on C,
infusible ; with micro gives a deep blue
bead in both flames ; soluble in HNO3,
yielding a pink solution.
Comp. It appears to be a hydrated
oxide of cobalt and manganese, but is
very uncertain in its composition. No
analysis of a British specimen is pub-
lished, but two foreign specimens
yielded 19 '45 of Co O and 35/47 of Co2
O3 respectively, there being in one case
a larger and in the other as large a per-
centage of oxide of manganese, together
with 20 per cent, of water. It should,
perhaps, be regarded as simply a cobaltio
variety of "Wad.
Loc. Eoscommon cliffs, St. Just ;
Huel Unity, Huel Gorland, and other
mines in Gwennap, in soft bluish-black
masses ; also Cheshire, Scotland, Ire-
land, Germany, &c.
Asphaltum. See Bitumen.
Assay. " A trial of the quality of
minerals ;" a determination of the quan-
tity of any element in a given com-
pound ; also the portion of substance tried.
Astringent. Anything having a taste
which seems to dry up the juices of the
palate and tongue is said to be astrin-
gent. Ex. Alum and copperas.
ATAOAMITE.
Rhombic, with a perfect brachy-
diagonal cleavage ; usually in aggregates
of acicular prisms ; or renif orm, granular,
massive, disseminated ; structure often
curved lamellar and radiating ; brittle
fracture conchoidal or uneven ; trans-
lucent to opaque ; vitreous or silky
colour various shades of green, mostly
dark ; streak light green ; H. 3 to 3'5
G. 4 to 4'3 (Botallackite 3 '6).
Var. Botallackite (Church) is, per-
haps, a variety of atacamite, it occurs in
minute interlacing crystals on killas ; it
is vitreous, pale green, with a white
§treak. Tallingite may, perhaps, be
another variety ; its colour is blue, anc
it occurs in "thin crusts consisting o:
irregular aggregations of minute globules
which appear botryoidal under the micro
•cope." It is, however, described under
its own name.
B. , etc. In matrass gives off water with
an acid reaction; with a strong heat
greenish sublimate is deposited ; on C
olours the flame bright blue ; with the
R. F. it is easily reduced to a malleable
>eadof Cu ; easily soluble in HClor HNO3
with little or no effervescence ; readily
oluble in ammonia, forming a deep blue
olution.
Comp. It is a hydrated oxychloride
)f copper. The following analyses, by
:*rofessor A. H. Church, of specimens
rom Botallack, shew the composition
>f a Cornish specimen of atacamite (a),
and another of botallackite (b); the
analysis of tallingite (c) and another
mineral examined by Professor Church
d) are subjoined for comparison : —
Oxide of a. b. c. d.
copper.... 54-32 66 '25 53 "57 67 '25
Copper 13-57 — 1011 —
Chlorine ... 15 '20 14 '51 11 '33 8 '73
Water 16 '91 22 '60 24 '99 26 '56
Total 100-00 103-36 lOO'OO 102'54
a) agrees very well with the formula
3CuH202 + CuCl2 + H20; (b) with
3CuH2O2 + CuCla + 3H2O ; (c) with
4CuH2O2 + CuCl2 + 4H2O ; (d) with
6CuH202 + CuCl2 + 6H20.
Loc. B< >tallack, Atacamite in crusts and
stalactitic tubes ; Botallackite in inter-
lacing crystals, which are translucent
under the microscope, and Tallingite as
thin crusts of very small blue globular
masses ; Atacamite occurs chiefly in Chili
and Peru, but also in Germany, Africa,
and South Australia ; it occurs also as a
volcanic product at Vesuvius and Etna.
Atacamite, Botallackite, and Tallingite
may be distinguished from malachite by
their little or no effervescence with
HC1, and from all the other British ores
of copper by their ready solubility in
strong ammonia.
Attle. Rubbish ; the refuse of a mine.
Attle heap — Mine burrow.
Augite. See Pyroxene.
Auriferous. Containing gold.
Augitic. Containing Augite.
AUTUNITE.
[Uranite; Calcareous Uran mica.]
rhombic ; but the brachy and macrodia-
gonal nearly equal ; crystals, like Fig. 122,
closely resembling those of Torbernite
(Chalcolite) see Figs. 74 to 76 and 89;
cleavage, basal, perfect ; sectile ; trans-
lucent ; sub-adamantine, pearly on the
cleavage ; greenish-yellow ; streak yel-
low; H. 1-2-5; G. 3-3-2.
B., etc. In matrass yields water and
turns to a straw yellow ; on C fuses at 2 to
a black mass with a semicrystalline sur-
face ; with soda forms a yellow infusible
slag ; soluble in HNO3, forming a yellow
solution.
12
AXINITE.
B. \BINGTONITE.
Comp. No analysis of a Cornish spe-
cimen has been published, but foreign
specimens yield about 15 7 of phosphoric
anhydride, 62 '7 of oxide of uranium, 6*1
of oxide of calcium, and 15 '5 of water.
With these proportions the formula will
be 2UVP2 + Ca + 8H2 (oxygen ratio
for protoxides, peroxides, phosphoric
anhydride, and water = 1:6:5:8).
Loc. South Huel Basset, in small
bright yellow, nearly transparent, crys-
tals ; Tolcarne, pale yellow inclining to
green, at 30 fathoms depth ; Huel Ed-
ward, St. Just; Gunnislake; Stenna
Gwynn ; Lostwithiel. Also France, Ger-
many, and the United States.
Obs. Autunite was formerly thought
to be isomorphous with Torbernite, and
both were classed together as Uranite,
but there seems reason to believe that
they are distinct in form as they differ
in composition. Autunite is said to be
optically biaxial, that is, to have two
axes of double refraction, which is the
case withrhombic minerals, but not with
those that are tetragonal. Autunite may
be distinguished from Torbernite by its
yellow streak; yellow solution in HNOg,
and by not yielding a bead of Cu with
soda before the blowpipe.
Angles.
MO- 90° 00' M M = 90° 00' nearly.
01 115 53 Ou 109 32
AXINITE.
Doubly oblique ; usually in very
oblique and unsymmetrical prisms, with
rough or striated faces ; often so flat as
to appear tabular, Figs. 184 to 187;
sometimes massive, curved lamellar, or
granular ; brittle ; fracture conchoidal
or uneven ; transparent to translucent
on thin edges ; vitreous and brilliant ;
trichroic ; brownish, bluish, greyish ;
streak white; H. 6 '5-7 ; G. 3 to 3 '3;
frictio-electric, pyro-electric.
£., etc. In matrass no change; on 0
fuses at 2 with intumescence to a dark
green magnetic glass, which in the O F
turns black ; with borax or micro Fe
and Mn reactions ; the powdered mineral
fused with soda on platinum foil yields a
green mass ; with fluor and monopotassic
sulphate, boracic acid may be detected ;
insoluble in H Cl until after fusion, when
it is readily decomposed, leaving a jelly
of silica.
Comp. It is an anhydrous and very
complex silicate and borate of alumina,
iron, manganese, magnesia, and licue.
No analysis of a British specimen is
published, but foreign specimens contain
quantities varying as follows :— Silica
41'5 to 45'0 ; alumina 13 '5 to 19 '0 ; per-
oxide of iron 7 '3 to 12 '3; manganic per-
oxide 1'2 to 10 -0; lime 12 '5 to 25 '8;
magnesia 0 to 2'2 ; boric anhydride 2'0
to 5 '6. With silica 41 '1, alumina 16*3,
peroxides of iron and manganese 15 '8,
lime 21 '3, boric anhydride 4 '6, the for-
mula may be written 12Ca 5A12 3Fe3
2B2 21Si (oxyqen ratio for protoxides,
peroxides, boric anhydride, and silica =
2 : 4 : 1 : 7), or SiO4 (2-7ths Ca. 4-7ths
Fe. Al. l-7th B.)2.
Loc. Rocks north of Botallack, Huel
Cock, and Trewellard, in fine brilliant
clove brown crystals, which have been
obtained as much as 1| inch across, like
Figs. 184 and 186, and forming a com-
pact mass, with garnet, schorl, &c. ;
Lamorna Cove, near Penzance ; Bos-
cawen cliffs, St. Burian, light greyish-
viol^t ; Carn Silver, Lamorran creek;
Carharrack ; Camborne Vean ; Trevas-
cus ; St. Columb ; Terrace-hill Quarry,
Callington ; Lostwithiel ; Huel Friend-
ship, near Okehampton ; Stickle path ;
Brent Tor. Also Norway, Sweden,
France, Spain, Italy, Germany, Russia,
United States.
Obs. Pseudomorphous crystals of
chlorite of the exact form of the St.
Just axinite have been found on Dart-
moor and at St. Just. The Cornish
crystals of axinite have the faces c. v.
p. r. z. usually predominating ; the faces
y. and c. are said to be peculiar to the
St. Just crystals. •
Angles.
PC = 113°
PI 151
P z 116
96
134
146
135
102
119
130
151
15'
03'
26
32
48
39
25
30
50
28
30
lu
r c
ry
r s
r v
r w
r x
U 8
vy
xy
cy
153° 25'
85 40
85
143
93
114
139
152
139
126
35
38
14
30
12
01
09
25
If
Ps
Pu
Pv
Pw
Px
wy 151 30 cy 156 20
Axis. Axes are imaginary lines, cross-
ing a crystal in its centre, to which its
faces may be conveniently referred.
See Crystallography.
Azurite. See Chessylite.
B.
BABINGTONITE.
Anorthic ; usually in small crystals,
like Fig 235 ; two perfect cleavages,
parallel to Oft. Also fibrous or radi-
ating ; brittle, fracture imperfect or
hackly ; thin splinters or laminae trans-
BARYTES.
BAYLDONITE
13
lucent ; vitreous ; blackish-green, or di-
chroic, green, and brown ; streak white
or greyish ; H. 5-5 '5 ; G. 3 '3-3 '5.
B., etc. In matrass unaltered, or
sometimes decrepitates ; occasionally a
little water is evolved ; after heating it
gives an alkaline reaction on test papers,
on C fuses at 3 to a brilliant brownish-
black globule, which is sometimes mag-
netic ; with borax forms a clear reddish-
yellow glass, nearly colourless on cool-
ing ; in reducing flame becomes greenish ;
with micro, the same reactions, but s»
skeleton of silica is left in the bead ;
scarcely acted upon by acids ; with soda
and nitrate of potash on platinum foil
the manganese reaction is readily ob-
tained.
Comp. Anhydrous silicate of iron and
lime. The following is a recent analysis
of a specimen from Devonshire, by Pro-
fessor Forbes, F.R.S.:—
Silica ........................ 4912
Alumina ..................... T60
Peroxide of iron ............ 978
Protoxide of iron ......... 12 '87
Oxide of manganese ...... 1*25
Lime .......................... 20'87
Magnesia ..................... 3'67
Loss on ignition ............ 0'73
99-89
this is nearly equal to 12Si Fe2 3Fe
6Ca or 6CaOSiO2 + 3FeOSiO2
or Si9O9Feo"3Cao"6Si3O3Fe2OTi.
Loc. In a railway cutting in Devon-
shire ; also in the Shetland Isles, and in
Norway.
Obs. It is, in appearance, much like
hornblende. The Devonshire mineral
'was discovered in 1854, and was so
abundant as to be worked as an ore of
iron.
Angles.
M t = 112° 30' O t = 88° 00'
OM 92 34 hg 90 40
Baryta. The oxide of the metal
Barium is so called.
BARYTES.
[Barite. Heavy spar.] Rhombic; in
tabular or prismatic crystals, like Figa.
130 to 135, which are all Cornish forms ;
single, aggregated, or drusy ; four dis-
tinct cleavages ; M. and O. perfect, a. and
t>. less perfect, the cleavages forming
angles of 90° 0', 78° 20' , and 101° 40' ;
also in foliated, columnar, radiated,
fibrous, granular, compact, earthy, or
stalactitic masses ; sometimes a curved
lamellar structure ; brittle ; fracture con-
choidal, but not easily obtained -. trans-
parent to opaque ; vitreous to resinous ;
colourless, or white, grey, yellow, blue,
red, brown ; streak white, or sometimes
slightly coloured like the specimen in
the earthy varieties ; H. 3-3 '5 ; G. 3-4 '7.
Var. Hepatite is an impure earthy
variety, emitting a fcetid odour by fric-
tion or percussion. Cawk is a dirty
white, earthy, opaque, massive variety.
B. , etc. In the matrass decrepitates ;
on C infusible, or fusible only on the
thinnest edges (Dana says fusible at 3);
when touched with HC1 and again
heated tinges the flame yellowish-green ;
with borax melts into a clear glass, which
turns yellow or brown on cooling ; with
soda fuses to a clear pearly mass, and
is absorbed into the charcoal ; if a
portion of the charcoal be then removed,
moistened, and placed upon a polished
surface of silver a black stain will be
produced ; insoluble in HC1 or HNO3.
Comp. Anhydrous sulphate of Barium ;
with baryta 65 '63, and sulphuric anhy-
dride 34-37, the formula will be Ba's or
SOj Bao". No analysis of a Cornish or
Devon specimen is known to the author.
Foreign specimens have sometimes a
large portion of the baryta replaced by
strontia.
Loc. The United Mines and Ale and
Cakes, Gwennap, from the 170 fathom
level, in semitransparent greenish -grey,
yellowish, or brownish crystals, some
like Fig. 137, which darken on long ex-
posure to light ; St. Austell ; Herods-
foot, in fine crystals ; Huel Mary Ann,
Liskeard, in fine transparent colourless,
or yellowish crystals, with pyrites and
fluor (Figs. 133 and 136, and also the
combination M O o d u); Trehane, ra-
diated, with green fluor; Hennock; Res-
tormel ; Menheniot, yellowish and trans-
parent, in a lead lode ; Babbicombe Bay,
on calcite ; Torquay ; Bridford, S. Devon ;
also Surrey, Derbyshire, Staffordshire,
Cumberland, Scotland, Norway, France,
Germany, United States, &c.
It is largely used as a paint; for giving
a smooth surface to paper-hangings, &o.
Angles.
M M' = 101° 40' O o = 127° 18'
MO 90 00 O d 141 09
Ma 129 10 dd 102 17
Oa 90 00 oo 74 36
Ob 90 00 Oz 115 42
u truncates the edge d a, n truncates
the edge Mb. MOo, MOoa, MObo d,
MOodu, MO»;z, MO i? or are all
Cornish forms.
Basalt Jasper. See Porcelain Jasper.
14
BASALTINE.
BERTHIERITE.
Basaltlne. An old name for horn-
blende.
Base. A compound of a metal and
oxygen, which by union with an anhy-
dride can form a salt. Thus in an analy-
sis of 100 grains of carbonate of lime
there would be obtained 56 grains of
lime and 44 grains of carbonic anhydride.
Here the 56 grains of lime would be
called the base.
BAYLDONITE.
Amorphous ; occurs in minute mam-
millary concretions, with a drusy sur-
face ; structure often somewhat reticu-
late ; brittle ; fracture sub-conchoidal or
uneven ; sub-translucent ; lustre strongly
resinous ; grass-green to blackish-green ;
streak siskin to apple-green ; H. 4*5 ;
G. 5'35.
B., etc. In matrass (fives off water and
turni black ; on C fuses at first to a
black bead; deflagrates; gives off an
alliaceous odour; leaves a hard white
metallic bead of Pb and Cu ; with borax
gives Cu reactions ; soluble in warm
HNO3, but not readily.
Comp. Hydrated arseniate of lead
and copper. The following is the mean
of three analyses of Cornish specimens,
by Professor A. H. Church :—
Arsenic anhydride 3176
Oxide of copper 30'88
Oxide of lead 30'13
Peroxide of iron, lime, and
loss 2-65
Water 4'58
Total 100-00
With arsenic anhydride 31 '6, oxide of
copper 32'8, oxide of lead 307, water 4'9,
the formula will be' Asa3CuPb3Ha (oxy-
gen ratio for R AsH2 = 4. 5 . 2) or PbO,
2CuO, As2O5 + CuH2O2 + H2O or AsaOa
Pbo"Cuo"2CuHo2 + OH2.
Loc. Found lately in Cornwall, by
Mr. Tailing, of Lostwithiel, and de-
scribed by Professor A. H. Church
(Journal of the Chem. Soc., II. vol. iii.,
265, 1865). It is often seen in old Cornish
collections of minerals.
Obs. An arseniate of lead and copper,
from Huel Alfred, in Phillack, was
analysed by Mr. Michell, in the year
1825, which may have been impure
Bayldonite. It was mammilated ; gra-
nular ; leek-green in colour. Its com
position was PbO 31 '5, CuO 28 '0, AsaO,
24-0, FeaO3 2-0, SiO2 lO'O, HaO 2U '
Beekite. See Calcedony.
Bell Metal Ore. See Stanntte.
BKRAUNITE.
Obliqu ; usually in foliated or ra-
diated masses, with one distinct and one
Indistinct cleavage, at an angle of 90° ;
also columnar or investing; brittle;
vitreous, pearly, or sub-metallic ; red or
reddish-brown ; streak dirty yellow ;
H. 2; G. 2-8-2-9.
B. , etc. In matrass gives off water and
turns darker ; on C alone fuses easily to
a dark magnetic globule, colouring the
flame bluish -green like Vivianite; with
borax gives Fe reactions ; soluble in HC1.
Comp. It is a hydrous ferric phos-
phate. No analysis is published.
Loc. Huel Jane, near Truro, on
Vivianite and Niccolite; also Bohemia,
Crimea, &c.
Obs. It appears to be an altered
Vivianite, from which it may be distin-
guished by the colour of its streak.
BERTHIERITE.
[Haidingerite.] Rhombic? Occurs in
indistinct confusedly aggregated prisms ;
granular or plumose ; several longitu-
cleavages, more or less distinct ; some-
times a lamellar structure ; brittle ;
opaque ; metallic, glimmering ; dark
•teel-grey, iridescent, or spotted red or
brown ; streak dark grey or black : H.
2 to 3 ; G. 4 to 4'3.
B., etc. In matrass fuses and gives »
faint yellow sublimate; with a strong
heat forms a black sublimate, which is
brownish-red on cooling ; on C fuses and
yields a dark magnetic slag, depositing a
white coating on the charcoal and giving
a sulphurous odour ; with borax the slag
gives Fe reactions ; soluble in HC1, yield-
ing an odour of sulphuretted hydrogen.
Comp. Sulphide of antimony and iron.
No analysis, of a Cornish specimen is on
record. Foreign specimens yield from
28-0 to 31'3 per eent. of sulphur, 52 '0
to 61 '0 of antimony, 9 '8 to 16 '0 of iron,
with sometimes a little zinc or manga-
nese. With antimony 51 7, iron, 17 '8,
and sulphur 30 '5 the formula may be
Fe3Sb4S9 or 3FeS + 2Sb2S3; with anti-
mony 60'0, iron 10 '4, and sulphur 29 6 =
Fe3Sb8S15 or 3FeS-t-4Sb2S3; with anti-
mony 57 '0, iron 131, and sulphur 29 '9
=Fe3Sb6S12 or3FeS 3Sb2S3 or FeSbaS4 or
Sb2S2Fes".
Loc. Near Tintagel ; and near Pad-
stow, in the antimony mines ; also France,
Germany, Hungary, United States, &c.
Obs. It has been worked as an ore,
but yields antimony of an inferior quality.
It is always associated with other ores of
antimony. It may be distinguished from
antimonite and jamesonite by the con-
siderable quantity of magnetic slag left
on charcoal after heating.
BERYL.
BISMUTH.
15
BERYL.
Hexagonal; usually in longitudinally
striated prisms, like Figs. 188, 193, and
194, with an imperfect cleavage, parallel
to O. ; sometimes in columnar aggregates,
or massive ; brittle ; fracture, sub-con-
choidal or uneven ; transparent to sub-
translucent ; vitreous or resinous ; some-
times colourless, but more usually wbite,
green, blue, red, yellow, grey, sometimes
parti-coloured, iridescent, or opalescent;
streak white; H. 7 '5-8-0; G. 2 '6-2 '8.
Var. Emerald is a fine green variety,
used in jewellery. The colour, in some
varieties at least, seems to be due to a
minute proportion of chromium. The
emerald has not been found in Cornwall.
£., etc. In matrass unchanged, or
altered in colour only ; on C alone the
same, sometimes fuses on thin edges ;
with borax forms a clear glass, often
tinged green or yellow ; on adding pow-
dered fluor spar the bead remains clear
while hot, but becomes opaque on cool-
ing ; not acted upon by acids.
Comp. Anhydrous silicate of Alumi-
nium and Beryllium, with usually small
portions of Or. Fe. Ca. Mg. or Na.; the
only mineral containing Beryllium found
in the United Kingdom. Foreign speci-
mens yield from 64'0 to 70'0 per cent, of
silica, 14'0 to 21 '0 of alumina, and 11 '0
to 15-0 of berylla. With silica 66 '8,
alumina 191, and berylla 141, the com-
position will be Al23Be6Si (oxygen ratio
for protoxide, peroxide, and silica =
1 . 1 . 4), or Si606Al2oviB«o"3.
Loc. Huel Castle, St. Just, amor-
phous; St. Michael's Mount, in small
bluish crystals with topaz and cassiterite ;
Mabe and Constantiue, in the granite
quarries, in well-defined dull white crys-
tals, embedded in fine-grained granite ;
Lustleigh, Devon, in granite ; also Scot-
land, Ireland, Norway, Sweden, Ger-
many, France, Italy, Siberia, India,
United States, &c.
Obs. Crystals of beryl are sometimes
very large. A crystal of beryl from the
United States was 4 feet 3 inches in
length, 2 feet 8 inches wide, and 1 foot
10 inches thick. Beryl may be distin-
guished from quartz by its superior hard-
ness and by the striation of its crystals,
which is longitudinal instead of trans-
verse; from topaz by the form of its
crystals (hexagonal prisms in beryl, rhom-
bic prisms in topaz), and the imperfection
of its cleavage.
Bindheimite. See Bleinierite.
BISMITE.
[Bismuth Ochre. Oxide of Bismuth.]
Cubical? massive and foliated ; earthy,
pulverulent, disseminate ; friable or very
brittle ; fracture earthy or conchoidal ;
opaque ; glimmering or dull ; yellow,
greyish, greenish ; H. '0 to 10 ; G. 4 '3.
/?., etc. In matrass turns darker and
gives off some water ; on C is readily re-
duced to a grey, brittle bead, depositing
a brownish incrustation ; soluble in HNO3
often with a slight effervescence ; the
solution yields a white precipitate when
much diluted with water.
Comp. Anhydrous oxide of bismuth,
often with a little Fe and As, besides
water absorbed from the atmosphere.
No analysis of a British specimen is on
record (unless the mineral called agnesite
be the same, but impure). With bismuth
89'65, and oxygen 10*35, the formula
would be Bi2 or Bi2O3. A specimen from
Germany yielded oxide of Bismuth 86 '4
per cent., equal to bismuth 75*3, and
oxygen 111, besides oxide of iron 51,
carbonic anhydride 41, and water 3'4.
Loc. Botallack ; Levant ; Huel Her-
land ; Cost all Lost, St. Eoach, in gra-
nite ; Restormel Iron mine, with quartz
and native bismuth. The mineral called
agnesite, which is probably an impure
bismite, occurred at Huel Coates, St.
Agnes ; also Germany and Siberia.
Obs. It may be distinguished from
the carbonate of bismuth by its very
slight effervescence in HNO3.
BISMUTH.
[Native Bismuth.] Hexagonal ; In
rhombohedrons, with an angle of 87° 40'
(Fig. 203) ; cleavage basal, very perfect
forming an angle of 123° 36' with the face
of the rhombohedron ; often macled, or
dendritic ; mossy, granular, compact,
foliate, or disseminate ; sectile or almost
malleable ; opaque ; lustre metallic ;
reddish white, often an iridescent tar-
nish ; streak grey and shining ; H. 2*0-
2'5 ; G. 9'6-9-S.
B., etc. In matrass melts and forms a
yellowish sublimate ; on C fuses at 1 and
volatilizes, forming a brownish incrus-
tation near the assay ; sometimes yield-
ing an alliaceous odour, and depositing a
white coating at some distance from the
assay, from the presence of arsenic ;
soluble in HNO3; the solution yields
an abundant white precipitate on the
addition of much water.
Comp. Bismuth, with traces of ar-
senic, sulphur, or tellurium. No analysis
of a British specimen is on record.
Loc. Botallack, in small crystals on
jasper; Levant, St. Ives Consols, lamel-
lar, very fine and pure ; Gt. Dowgas j
Dolcoath, in purple and greeH fluor;
16 BISMUTHINITE.
BITUMEN.
Huel Herland ; Huel Sparnon, in fea-
thery masses, with erythrine and smal-
tite ; Trugoe, near St. Columb ; also
Cumberland, Scotland, Norway, Sweden,
France, Germany, Spain, United States,
&c.
Obs. The bismuth of commerce is
mostly obtained from native bismuth.
Masses of bismuth of several pounds
weight are said to have been found loose
in the soil near Redruth. Cupreous bis-
muth is said to occur at Huel Buller, and
arsenical bismuth at St. Just. Bismuth
is usually associated with tin, cobalt, or
silver ores. The usual minei's test for
bismuth is to heat the ore on a shovel,
when it melts into globules readily. A
rude assay is often made by heating the
ore, without fluxes, in a crucible, when
the metal fuses, and from its high spe-
cific gravity sinks to the bottom.
A ngles.
RR = 87° 40'
Ro 123 36
BISMUTHINITE.
[Bismuthine. Bismuth Glance.] Rhom-
bic ; in acicular prisms, like Figs 98 and
99 ; deeply striated longitudinally, with
perfect cleavages, at right angles to each
other, and parallel to a. and o.; also in
columnar aggregates ; massive, with fo-
liated, radiated, or fibrous structure ;
granular ; compact ; disseminate ; brittle,
or sectile ; opaque ; metallic ; tin-white
to lead-grey ; often iridescent ; streak
grey, shining; H. 2 '0-2 "5; G. 6 '4-6 '6.
B.. etc. In matrass gives a yellowish
sublimate ; on C fuses at 1, boils, coats
the charcoal yellow, and gives off a sul-
phurous odour ; tinges the flame blue ;
may be entirely volatilized in the O F ;
in R F yields a grey, somewhat brittle
bead of Bi ; decomposed by hot HNO3,
which dissolves the Bi and leaves the S ;
the solution diluted with a large quan-
tity of water yields an abundant white
precipitate.
Comp. Anhvdroua sulphide of bis-
muth, often containing small quantities
of Fe and Cu. The following are analy-
ses of Cornish specimens : —
Bismuth ... 72a;49 ... 78 ;00 ... 68*53
Iron 3'70 ... T04 ... 2'90
Copper 3'81 ... 2'42 ... 2'98
Sulphur ... 20-00 ... 18-42 ... 19'33
Silica — ... — ... 5-01
Totals... 100-00 ... 99-88 ... 9875
a. and c. are by "Warrington, b. is by
Rammelsberg.
With bismuth 8074, and sulphur 19 '26
(Bi » 208), the formula will be Bi3S3.
Loc. Botallack ; Huel Cock ; Levant ;
Balleswidden ; Dolcoath ; East Pool,
in quartz ; Pednandrea, some of the
prisms macled at one end and pointed
at the other so as to bear some re-
semblance to a pin ; Huel Herland ;
Huel Sparnon ; Fowey Consols ; Lanes-
cot ; St. Columb, in stream works, as
water-worn pebbles, like stream tin ;
Huel Arthur, Calstock ; George and
Charlotte mines, with childrenite ;
Great Dowgas ; Devon and Cornwall
United Mines, Devon, in fine crystals ;
Ivy Tor mine, near Okehampton ; also
Norway, Sweden, Germany, &c.
Obs. It may be distinguished from all
similar minerals which occur in Devon
or Cornwall by the white precipitate
which falls from its solution in HNO3 on
the addition of water. It usually occurs
in veins or cavities ("vugs") in quartz,
slate, or granite.
Fig. 98 is a prism ; Fig. 99 a section of
the same.
Angles. MM = 91° 00'
M a 134 30
ba 90 00
Bisulphuret of Copper. See Covelline-
Bisulphuret of Iron. See Pyrites and
Marcasite.
Bitter Spar. See Dolomite,
BITUMEN'.
Asphaltum. Mineral Pitch. Amor-
phous, brittle, sectile, or plastic ; frac-
ture conchoidal or hackly ; opaque ;
lustre resinous, brilliant to glimmering ;
brownish-black or velvet-black ; streak
greyish; H. 0 to2'0, G. 1-1 '2; frictio-
electric.
Var. 1. Naphtha includes the fluid
varieties.
2. Petroleum. Rather thicker than
common tar, but hardens by keeping;
has a bituminous odour ; is soluble in
ether and alcohol, probably a mixture of
naphtha and asphaltum.
3. Elaterite. Elastic and flexible, like
caoutchouc.
4. Asphaltum. Solid ; fracture con-
choidal ; almost entirely soluble in ether.
B. , etc. All burn with a bright smoky
flame. Asphaltum melts at about 100°
C, and when burnt leaves a small quan-
tity of incombustible ash.
Comp. All are hydro-qarbons of very
uncertain and variable composition.
Asphaltum contains from I'O to 12 "0 per
cent, of oxygen and nitrogen.
LOG. Petroleum. —Huel Unity and
Huel Jewell, G wen nap ; Carharrack
Mine, St. Day ; North Treskerby, Red-
ruth ; Chudleigh, Devon.
Asphaltum.— Poldice Mine, coating
BLACK COPPER.
BLENDE.
17
quartz ; Car-barrack ; South Huel Towan ;
Cook's Kitchen ; North Treskerby ; Great
HuelCrofty; North Roskear; also Derby-
shire, and other parts of England ; Scot-
land, Germany, Greece, West Indies, &c.
Obs. It is probable that the above
minerals are distinct species, and not
mere varieties.
Black Copper. See Melaconite.
Black Hematite. See Psilomelane.
Black Jack. See Blende.
Black Lead. See Graphite.
Black Sulpburet of Silver. See Ar-
gentite.
BLEINIERITE.
[Bindheimite.] Amorphous, reniform,
stalaciitic, spheroidal, investing ; com-
pact, with curved lamellar structure, or
earthy ; brittle ; translucent to opaque ;
vitreous, resinous, or dull ; yellow, some-
times white, grey, brown ; streak like
the colour, usually yellow; H. 2*0 to
4'0; G. 3'9 to 5-0.
B., etc. In matrass gives off water
and becomes darker ; on C fuses at 1 (?) ;
Is readily reduced to a grey, brittle
globule of antimony and lead, coating
the charcoal yellow near the assay, and
white outside the yellow ; sometimes a
very slight garlic odour ; with soda,
after long blowing, yields a malleable
bead of lead ; soluble in HC1.
Comp Hydrated Antimonate of Lead.
The following are analyses of Cornish
specimens : —
a. b. c. d.
Oxide of an-
timony ... 42-22 42-44 4670 47 "36
Oxide of lead 47-04 46 '68 43 "94 40 '73
Oxide of iron — — 1*44 —
Lime — — 1'34 —
Oxide of ar-
senic — — trace —
Water 11 '50 1198 6'46 11-91
Totals ... 100-76 101 10 99 '88 100 '00
a. b. and c. were analysed by Heddle, d.
by Percy, a. and b. were white, c. was
brown. With antimonic oxide 42 '2, oxide
of lead 46 5, water 11 '3, the formula may
be written Pb3b23H2, or Sb2O4Pbo"l
30H2.
Loc. Trevinnick Mine, Endellion, in
large yellow detached masses, near the
surface ; also on Jamesonite, with anti-
monite and other ores of antimony ;
also found in Norway and Siberia.
Obs. It appears to be a product of the
decomposition of Jamesonite.
BLENDE.
[Sphalerite. Black Jack.] Cubical,
in cubes, tetrahedrons, rhombic dode-
cahedrons, octahedrons, &c. ; often
macled (Figs. 1, 2, 3, 8, 10, 35, 37, 39,
42, 52, 56], with a highly perfect dode-
cahedral cleavage ; also botryoidal, fi-
brous, massive, compact, plumose, radi-
ated, lamellar, or granular ; brittle;
fracture conchoidal or uneven, but not
often to be observed ; semi-transparent
to sub-translucent ; lustre sub-metallic,
adamantine, or resinous ; yellow, brown,
red, black, rarely green or white ; streak
white or light brown; H. 3.5-4; G.
3 '9-4 2; some varieties pyro or frictio-
electric.
Var. Cleiophane is a pure white
variety ; Marmatite and Christophite
are dark brown or black, and contain 10 '0
per cent (or more) of iron ; Przibramite
is a variety containing from I'O toS'O
per cent, of cadmium. It is usually dark
in colour, and often granular or fibrous.
B., etc. In matrass decrepitates, and
sometimes changes colour, or yields a
alight white or yellowish sublimate ; on
C infusible, or fusible oi.ly on thin edges ;
with borax or soda and a strong heat ex-
hibits a light green incandescence, and
deposits an abundant white incrustation,
which when treated with Co becomes
green ; soluble in strong HC1 or HNOs,
giving off H2S.
Comp. Anhydrous sulphide of zinc.
The following are analyses of Cornish
specimens : —
a. b.
Zinc 58-64 ... 43'00
Iron 11-96 ... 22'50
Copper — 0'80
Sulphur 28-64 ... 31 '50
Silica 0-76 . —
Totals 100-00 ... 97-80
a. is by Thomson, b. is from Huel Ann,
analysed by Gregor. The sp. gr. of a.
was 4 "049, the colour was blackish-brown.
Foreign specimens yield from 44 '6 to
66 '3 of zinc, 0 to 18*2 of iron, 32 '1 to
33 '8 of sulphur. With sulphur 33, and
zinc 67, the formula will be ZnS.
Loc. Botallack Mine ; Goonhavern
Mine, Newlyn ; West Huel Darlington ;
St. Agnes, in fine crystals (Figs. 37, 39,
&c.); Huel Sperries ; Nangiles ; Huel
Vor ; Huel Rose ; Huel Penrose ; Lanes-
cot ; Huel Brothers, Calstock ; Par Con-
sols ; Huel Crofty ; Huel Unity, white,
mammillated, and fibrous; Fowey Con-
sols, fibrous, white, and transparent (Cle-
iophare), andcadmiferous ; Landkey, near
Barnstaple; Beeralston; Tamar Mines ;
Hennock; Combemartin; Huel Betsy
and Huel Friendship, Tavistock; and
many other localities in Cornwall and
Devon.
18
BLOODSTONE.
BLOWPIPE.
Obs. By oxidation it sometimei gets
covered with a coating of Goslarite.
Blende often accompanies ores of lead,
tin, and copper, and is usually considered
a good sign. Hence the expression,
"Jack rides a good horse."
A ngles.
a a = 90° 00' o a = 125° 16'
dd 120 00 ma 154 46
oo 109 28 mo 150 30
oo' 70 32
Blistered Copper Ore. See Chalcopy-
rite.
Bloodstone. S«e Calcedony (Helio-
trope.)
Blowpipe. An instrument used for
the purpose of directing the flame of a
lamp or candle so as to concentrate its
power. It is much used in testing
minerals. The complete blowpipe or
pyrognostic examination of a mineral
consists of eight or more distinct opera-
tions, but some of these may usually be
omitted with advantage. The operations
are as follows : —
1st. Heating the assay in a small tube
of hard glass, sealed at one end, and
known as an "ignition tube," "closed
tube," or "matrass." The matrass
should be two or three inches long,
and from one-eighth to one-quarter inch
in diameter. It must be clean and dry.
A spirit lamp is the best source of heat
for this experiment, and the assay should
be heated gradually, the better to see
the changes produced ; at the close of
the operation the flame may be urged
with the blowpipe if no change, or but
little, haa been already effected. The
changes to be looked for are —
a., changes of colour ;
b. , decrepitation ;
c., deposition of moisture, or a sub-
limate, on the cool part of the
tube;
d., the evolution of a rapour or
peculiar odour.
2nd. A fragment of the substance to
be examined is placed in a tube about
six inches long, open at both ends, the
tube being held in an inclined position
over the flame. As before, the flame
may be urged by the blowpipe towards
the close of the experiment. The effects
to be noted are the same as in the first
instance, but the sublimates will some-
times be different, and the odours more
distinct.
3rd. A little of the coarsely-powdered
assay is placed in a small cavity scooped
on the surface of a piece of charcoal with
a penknife. The flame of a candle or of
an oil lamp is then directed upon the
assay by means of the blowpipe, using
the "oxidising flame" ("OF"). The
effects to be observed are —
a., degree of fusibility;
b., evolution of vapour or odour ;
c., deposition of an incrustation on
the cool part of the charcoal
support ;
d., reduction to a bead of metal ;
e., non-volatile residue;
f., tinging of the tip of the flame.
4th. If the non-volatile residue is
white, a drop of a strong solution of
Cobaltic nitrate ("Co") should be
dropped upon it, and the mass again
heated, noting the tint produced by this
treatment.
5th. If the residue be any colour other
than white it should be mixed with a
little dry carbonate of. soda ("soda")
and heated strongly, using the "reducing
flame" ("RF"). In some very obstinate
cases a little borax or cyanide of potas-
sium may be mixed with the soda with
advantage. The result to be looked for
is the production of a bead of metal. If
the portions of reduced metal be very
small they may escape observation ; in
this case the portion of charcoal round
the assay should be cut out, ground up
! with water in a small mortar, and the
! light carbon and soluble soda washed
I away. Any shining particles of metal
I will then be easily detected.
6th. Make a small loop in the end of a
i piece of platinum wire, heat it in the
i flame of the spirit lamp, dip it into pow-
j dered borax, hold it again in the flame
1 until the borax has melted into a clear
glassy bead, add to it a very little of the
powder of the substance to be tested,
heat it again, in the OF first, then RF
if no distinct colour is produced, take a
little more of the assay and repeat the
operation, several times if necessary.
7th. Repeat the sixth experiment,
using a bead of microcosmic salt
(" micro.") instead of the borax.
8th. Hold a fragment of the substance
under examination with a pair of plati-
num-pointed forceps, and direct the tip
i of the OF upon it. Observe any change
of tint that may be produced in the
flame, and also the degree of fusibility
(see " Scale of Fusibility "), if the speci-
men be fusible.
In the absence of platinum forceps, a
piece of platinum wire tightly twisted
round the specimen will sometimes suf-
fice. The eighth operation is of greatest
use in the absence of such substances as
give sublimates in the matrass or open
tube, incrustations on charcoal, and
coloured beads with micro, and borax (see
BLUE COPPEE.
BBAUNITE
19
operations 1 to 7). When such results
have been observed in the first seven
operations the eighth should be omitted,
or the platinum will be injured.
An assay piece the size of a mustard
•eed will generally be sufficient, and
will be more manageable than a larger
piece. For the detection of substances
present in small quantity, however, it
will be sometimes necessary to take a
larger piece.
The results of each operation should
be carefully compared with the blowpipe
tables in the first part of the book.
Blue Copper. See Covelline and Ches-
sylite.
Blue Iron Earth. See Vivianite.
Blue John. A Derbyshire name for
Fluor.
Blue Lead. See Galena.
Blue Malachite. See Chessylite.
Bog Iron Ore. See Limonite.
Bog Manganese. See Wad.
Borate. A compound of Boric anhy-
dride with a metallic oxide; or Boric
acid in which the hydrogen has been
replaced by a metal.
Borax. Borate of Soda. It is much
used in the blowpipe examination of
minerals.
Bornite. See Erubescite.
Botallackite. See Atacamite.
Botryoidal. Like a bunch of grapes.
Malachite and Blistered Copper Ore are
examples of botryoidal minerals. When
the rounded prominences are larger and
less distinctly separated, the mineral is
mammillate ; when the prominences are
very irregular in size, and the larger
ones themselves broken up by smaller
prominences, the specimen is said to be
reniform ; when almost spherical, the
term globular is used.
BOURNONITE.
[Endellionite.] Khombic ; usually in
modified prisms, like Figs. 120 and 123,
or macles, like Fig. 121 ; also massive,
granular, compact, investing, or disse-
minate ; brittle ; fracture sub-conchoidal
or uneven ; opaque ; lustre metallic,
brilliant ; steel grey to blackish-lead
grey ; streak the same ; H. 2 '5-3 ; G.
57-5-9.
Tar. Wheel ore and cog-wheel ore
are names applied to finely macled
varieties, somewhat like Fig. 121.
B., etc. In matrass decrepitates and
yields a dark red sublimate ; in the open
tube gives a sulphurous odour and a
white sublimate of oxide of antimony ;
on C fuses at 1, and gives a white coat-
ing, and afterwards a yellow one nearer
the assay ; by alternately making use of
the O F and R F a bead of Cu is pro-
duced, more readily on the addition of a
little soda ; decomposed by HNO3, which
forms a blue solution, and leaves a resi-
due of sulphur, antimony, and lead.
Gomp. Anhydrous sulphide of lead,
copper, and antimony.
The following are analyses of Cornish
specimens : —
a. b. c. d.
Antimony ... 24-23 28 "50 26 '30 25 '00
Lead 42-62 39'00 40'80 41 '00
Copper 12-80 13'50 12'70 1300
Iron 120 TOO — VOO
Sulphur 17-00 16-00 20 '30 20 '00
Totals 97-85 98 00 10010 100 '00
a. was a specimen from Endellion,
analysed by Hatchett ; b. from Nansloe,
by Klaproth ; c. and d. were Cornish
specimens, analysed by Field and Smith-
son.
With antimony 24 '8, lead 42 '4, copper
12-9, and sulphur 19 '9, the formula will
be SbPbCuS3 or Sb2Pbs"2 (Cu2S2).
Loc Huel Boys, Endellion (Figs. 120,
123), where it was first discovered by
Count Bournon ; St. Merryn, Padstow ;
Nansloe, Helston ; Budock Vean, near
Falmouth, crystallised, compact, and mas-
sive ; Herodsfoot, in crystals, like Fig.
121, in simple crystals, like Fig. 120,
filling hollow crystals of galena, accom-
panied with Barytes, Fahlerz, and hacked
quartz, or massive ; Beeralstone ; also
France, Germany, Itaiy, Mexico, Chili,
Peru, &c.
Obs. It is usually associated with an-
timonite, jamesonite, galena, chalcopy-
rite, and chalybite.
Angles.
MM = 93° 40' O o = 13ft8 17'
Mb 136 50 Ou 146 45
Oa 90 00 Oy 127 20
Ob 90 00 ab 90 00
On 138 06 ef 118 04
Ox 154 27 e b 154 52
Bovey Coal. See Coal.
Brachydiagonal. The shorter lateral
axis of crystals in the rhombic system is
so called ; also a cleavage plane parallel
to this and the principal axes.
Brass Ore. An intimate mixture of
Blende and Chalcopyrite, found at some
mines in Cornwall.
BRAVNITE.
Tetragonal, the pyramid scarcely dif-
fering from Fig 1 ; often in macles of
three ; also massive, brittle ; fracture
uneven; opaque; lustre sub-metallic;
colour dark brownish-black ; streak the
same ; H.6-6'5 ; G. 4'7 to 4 '82.
#., etc. In matrass no change ; on C
infusible ; with soda, borax, or micro.
20
BRECCIA.
BBOOKITE.
gives Mn reactions ; the powder soluble
in warm HC1 with evolution of 01, some-
times a little gelatinous silica is left un-
dissolved.
Comp. Anhydrous proto-peroxide of
manganese with s 'me silicate of manga-
nese. No analysis of a British specimen
is on record. Foreign specimens yield
from 80 to 87 per cent, of protoxide of
manganese, 8 to 10 per cent, of oxygen,
and 8 '0 per cent, of silica. With oxide
of manganese 82'1, oxygen 9'3, and silica
8'6, the formula may be 4Mn2 + Si O2 or
MnO + 3Mn2O3 + MnSiO4.
Loc. It is said to have been found in
the manganese mines near Launceston ;
found in Piedmont, Germany, and Nor-
way, Elba, India, &c.
Breccia. Amass of angular fragments
of rock, cemented together by some other
material.
Brick Red Copper Ore. See Cuprite
(Tile Ore).
Bright White Cobalt. See Cobaltite.
Brittle. Easily broken. On attempt-
ing to cut a brittle mineral the fragments
usually fly in powder from the edge of
the knife with some considerable degree
of force.
BROCHANTITE.
[Warringtonite.] Rhombic ; in tabu-
lar or short prismatic crystals, vertically
striated, and in appearance somewhat
like Fig. 189, but shorter ; cleavage per-
fect, parallel to O ; also in acicular
groups or drusy crusts ; or massive,
reniform, columnar ; brittle ; fracture
conchoidal; transparent to translucent;
lustre vitreous, pearly on cleavage plane ;
emerald green to blackish-green ; streak
bright green; H. 3 to 4; G. 37
to 3'9.
Var. Brochantite, crystals vertically
striated; H. 3 "5-4; G. 378-39. War-
ringtonite occurs in non-striated crystals,
in form like a doubly curving wedge ;
paler green than ordinary brochantite ;
H. 3-3-5; G. 3'39-3'47. Woodwardite
may also belong here, but is described
under Langite.
B., etc. In matrass yields water with
an acid reaction and turns black ; on 0
fuses and yields a bead of Cu, with soda
gives the reaction for sulphuric acid ;
insoluble in water, soluble in HC1, the
solution yields an abundant white preci-
pitate with solution of Ba Cl.
Comp Hydrated cupric sulphate.
The following are recent analyses of
Cornish specimens :—
a. b. c.
Sulphuric anhy-
dride 172 18-93 1673
Oxide of copper 68 '8 68 '27 68 '24
Oxides of, iron
and zinc I'O — —
Lime 08 — —
Water 13 '2 12'22 14'64
Insoluble matter — 0'58 —
Totals 101-0 100-00 99 '61
a. is by Pisani, b. by Warrington, c. by
Maskelyne.
With sulphuric anhydride 19 '9, oxide
of copper 69 -0, and water 111, the for-
mula may be 7Cu 36 5H2 or S2O4Cuo"2 +
5CuHo2.
Loc. Several specimens, both of Bro-
chantite and Warringtonite, have been
found in Cornwall; it also occurs in
Cumberland, Germany, Ural, Mexico,
Chili, &c.
Bronzite. See Diallage.
BROOKITE.
Rhombic; crystals usually more or
less tabular, like Fig. 147, and striated,
dull, or uneven ; cleavage macrodiagonal,
sometimes distinct ; brittle ; fracture con-
choidal or uneven ; translucent to
opaque ; lustre adamantine or sub-metal-
lic ; reddish or yellowish-brown ; streak
yellow or white ; H. 5'5-6 ; G. 4 to 4'2.
B. , etc. In matrass unchanged ; on C
infusible ; with micro, a brownish-yellow
glass, &c., like anatase ; insoluble in
HC1 or HNO3. If the powdered mineral
be fused with potash on Pt foil, dis-
solved in HC1, and the solution boiled
with metallic tin, it becomes violet, and
red on dilution with water.
Comp. Titanic anhydride, Ti or TiO2,
like anatase and rutile. No analysis of
a British specimen is on record. Foreign
specimens contain from 94 to 99 per cent,
of TiO2, the rest being peroxide of iron,
alumina, or water.
Loc. Virtuous Lady Mine, in micro-
scopic crystals, embedded in chalybite,
with chlorite and anatase; also Wales,
France, Switzerland, Sicily, United
States, &c.
Obs. Titanic anhydride is trimor-
phous, being pyramidal in anatase and
rutile, but with different parameters ;
and rhombic in brookite. The face b is
usually striated parallel to its intersec-
tion with M.
A ngles.
MM' = 80° 10' b9 - 104' 06'
M b 139 5S b « 112 12
BEOWN HEMATITE.
CAXCEDONY.
21
Brown Hematite ; Brown Iron Ore ;
Brown Ochre. See Limonite.
Brown Lead Ore. See Pyromorphite.
Brown Spar. See Dolomite.
Buntkupferz. See Erubescite.
C.
Cairngorm. See Quartz.
GALA MINE.
[Smithsonite (Dana).] Hexagonal; in
obtuse rhombohedrons, often curved ;
sometimes tabular ; perfect rhombohe-
dral cleavage ; crystals usually indistinct ;
often compact, with the appearance of
chalcedony ; reniform, botryoidal, fi-
brous, stalactitic, investing ; cellular,
granular, earthy, friable ; brittle ; frac-
ture conchoidal or uneven ; transparent
to opaque ; vitreous, pearly, or dull ;
colourless, but more frequently white, or
various shades of green, yellow, grey, or
brown ; streak white or slightly coloured ;
H. 5 ; G. 4-4*5.
£., etc. In matrass sometimes decre-
pitates and loses colour ; on C infusible ;
moistened with Co and again heated
turns green on cooling ; with soda yields
an abundant white coating of oxide of
zinc, which becomes green when treated
with Co; when cadmium is present a
brown coating is also formed; soluble
with effervescence in HC1.
Comp. Anhydrous carbonate of zinc.
No analysis of a specimen from Cornwall
or Devonshire has been made, but a spe-
cimen from Somersetshire yielded —
Oxide of zinc 64 '8, carbonic anhydride
35*2, which agrees exactly with the for-
mulae ZnC or ZnCO3 or COZno". Some
foreign varieties contain as much as 53 '0
per cent, of carbonate of iron, or 15 '0
per cent, of carbonate of manganese.
Loc. Huel Mary, Lelant ; Fowey Con-
sols ; Great St. George Mine ; also Somer-
setshire, Derbyshire, Cumberland, Wales,
Scotland, Ireland, Belgium, France,
Spain, Italy, Germany, Hungary, Sibe-
ria, United States, &c.
Obs. It commonly occurs in limestone
rocks, associated with galena and blende.
Calcareous Iron Ore. See Chalybite.
Calcareous Spar. See Calcite.
Calcareous Uran Mica. See Autunite.
CALCEDONY.
Calcedonic Quartz ; amorphous ; bo-
tryoidal, stalactitic, nodular, concre-
tionary, or lining cavities in quartz or
other f ocks ; brittle ; fracture flat con-
choidal or splintery ; semi-transparent to
opaque ; resinous or waxy; shining,
glimmering; white, grey, yellow, red,
brown, green, blue, black ; often clouded,
striped, or mottled ; streak white ; H.
6-6-5 ; G. 2-6
Var. 1. Calcedony proper; usually
stalactitic or botryoidal ; often very deli-
cate tints.
2. Carnelian ; reddish or brownish,
pale or deep in tint.
3. Chrysoprase ; apple-green ; the co-
lour due to oxide of nickel, from 0'4 to
1*0 per cent.
4. Prase ; translucent and dull leek-
green. The name is also applied to
hyaline quartz when of the same tint.
5. Plasma ; sub-translucent ; bright
green, sometimes dotted with white.
6. Heliotrope or bloodstone is the
same, dotted with red. The green is often
duller in heliotrope.
7. Agate is a variegated calcedony ;
the colours in bands or clouds.
8. Moss-agate or Mocha-stone, the
same, but the markings are dendritic or
moss-like.
9. Onyx is a banded agate, the bands
even and distinctly separated. In fortifi-
cation agate the bands are in angular
lines, something like the ground plan of
a fortification.
10. Sardonyx is the same, but some of
the layers are like carnelian.
11. Agate Jasper is a jasper with vein-
ings or markings of calcedony.
12. Siliceous sinter is an irregularly
cellular calcedonic quartz deposited
from waters holding silicates in solution.
13. Flint is like Calcedony, but nearly
opaque, and of duller tints ; usually
grey, smoky-brown; or brownish-black;
the exterior is usually white, from a
thin coating of silicate of lime ; lustre
glimmering ; fracture deep conchoidal.
Thin splinters often exhibit organic
markings when viewed by transmitted
light.
14. Hornstone, like flint, but more
brittle, and the fracture splintery.
15. Basanite, Lydian Stone, Touch-
stone ; velvet-black ; compact, and the
fracture not splintery. It is often slightlj
laminated.
16. Jasper. It is opaque ; yellow, red,
brown, dirty-green, greyish-blue, brown-
ish-black ; striped ; the colour is gener-
ally due to oxide of iron. It is usually
accounted a separate sub-species, and is
described as such.
17. Beekite is a calcedonic pseudo-
morph, after various species of coral. It
often contains some of the original car-
bonate of lime.
£., etc. In matrass sometimes changes
colour, and usually yields a little water ;
on C alone infusible ; with soda dissolves
CALCITE.
CALCITE.
readily with effervescence to a clear
glass, of a colour like that of the assay ;
soluble in borax, with generally a Fe
reaction ; insoluble in micro. ; insoluble
in acids ; slightly soluble in KHO. After
strong heating has a sp. gr. of 2 '2.
Comp. Silicic anhydride or silica,
SiO2, like hyaline quartz usually con-
tains some oxide of iron, nickel, or man-
ganese, and a little water. A grey cal-
cedony from Hungary afforded — Silica
98 '97, peroxide of iron 0 53, carbonate of
lime 0'62. A clear red carnelian yielded
0*5 of peroxide of iron. An apple-green
chrysoprase from Silesia yielded I'O per
cent of oxide of nickel.
Loc. a. Calcedony. — Trevascus Mine,
Gwinear ; Ponsanooth, in greenstone ;
North Pool and Pednandrea, with cassi-
terite, very beautiful specimens, white,
pale yellow, grey, brown, blue, black, some
with a pearly grey enamel or incrustation ;
Dolcoath; East Pool ; Botallack ; Boscas-
well; Balleswidden, and most of the St.
Just mines ; Goonhilly Downs ; Lanescot ;
Huel Maudlin ; Beeralstone ; Haytor ;
near Sidmouth ; near Beer ; Blackdown-
hills ; Torquay ; Broadhembury and
Whitstone Pits, pseudomorphous after
coral (Beekite) ; in rhomboids and six-
sided plates, pseudo. after calcite and
dolomite, at St. Just and North Eoskear ;
in tabular crystals, pseudo. after barytes,
in fine specimens at Herodsfoot and
Huel Mary; after calcite and datholite
at Haytor (Haytorite) and North Eos-
kear.
b. Flint. Orleigh Court, near Bide-
ford, with chert, green earth, and hema-
tite forming a breccia ; Dunscombe-hill,
near Sidmouth, Blackdown-hills, and
other localities in Devonshire, not rolled ;
Branscomb cliff ; White cliff, near Chard ;
Buckland Brewers ; Haldon ; Tregoning-
hill and Trewavas, chipped ; Vorlas,
Ludgvan ; Marazion beach ; Looe Bar,
Portreath, and most of the beaches of
Cornwall, and the Scilly Isles.
c. Agate. Carn Brea-hill, south-east
side ; Huel Sparnon, Looe Bar, and near
Gweek (fortification); Budleigh Salter-
ton, in a bed of rolled pebbles ; Haytor ;
Mary Church, Kynance, £c.
d. Prase. North Eoskear, in white
quartz ; Garras Mine, near Truro.
e. Carnelian. Blackdown-hills, Devon.
f. Hornstone. — East Tamar; Beeral-
stone, pseudomorphous after fluor; Pen-
mare Point; Herodsfoot ; Orleigh Court;
White cliff ; Branscomb cliff ; Haldon.
CALCITE.
[Calc Spar.] Hexagonal; in rhombo-
hedrons, threte and six-sided prisms,
! with trihedral summits ; in scalenohe-
drons ; in hexagonal plates, lens-shaped
j crystals, &c., see Figs. 188, 195, 197,
I 200, 201, 217, 218, 222, 223, 226,
227, all of which, with many others, have
been observed in Cornwall or Devon ;
with three highly perfect cleavages,
forming angles of 105 '5; also massive,
compact, granular, or lamellar ; stalac-
titic, coralloid, fibrous, nodular, &c., or
pseudomorphous after aragonite, gyp-
sum, felspar, and other minerals ; brit-
tle ; fracture conchoidal, granular, or
earthy ; transparent to opaque ; lustre
vitreous to pearly, brilliant to dull;
colourless, or white, grey, yellow, pink,
red, green, blue, brown, black, parti-
coloured ; streak white, or slightly tinged
like the colour; H. 2 '5-3; G. 2 '5-2 "8.
strongly doubly refractive when trans-
parent.
Var. 1. A pure transparent variety,
with very perfect rhonibohedral cleavage
is called Iceland spar or doubly refrac-
ting spar.
2. A variety composed of small scalen-
ohedrons projecting from a mass is called
dog-tooth spar.
3. Satin spar is a fine fibrous variety.
4. Schiefer spar is lamellar, friable,
and tender ; by some supposed to be
pseudomorphous after selenite.
5. Marble is massive and granular.
6. Limestone is massive and compact.
7. Stalactite and Stalagmite are varie-
ties formed by deposits from water con-
taining lime in solution.
8. Oolite is composed of small rounded
concretions.
9. Pisolite, of larger concretions.
10. Swinestone is a variety which emits
a foetid odour when broken.
11. Chalk is an earthy variety, made
up of fragments of minute shells,
sponges, &c.
Many other varieties have received
distinct names.
-B., gtc. In matrass decrepitates, loses
colour, or remains unchanged ; on C in-
fusible, but becomes alkaline, glows,
colours the flame brick red, especially
after being moistened with HC1 ; with
soda fuses to a clear mass at first, but
finally the soda sinks into the charcoal
and leaves a white infusible mass ; solu-
ble in borax with effervescence, the bead
if saturated becomes white and opaque
on cooling, freely soluble even in lumps
with brisk effervescence in dilute HC1.
Comp Anhydrous carbonate of cal-
cium, but often containing a consider-
able percentage of the carbonates of iron,
magnesia, or manganese. No analysis
CALCITE.
CASSITEEITE.
23
of a specimen from Corn wall or Devon is
known to the author. With lime 56 '0,
and carbonic anhydride 44 '0, the formula
will be CaC or Ca CO3 or COCao".
Loc. a. Calcite. Botallack.HuelOwles,
and other St. Just mines, in pale pink
crystals, like Figs. 200 and 223, and other
forms ; Huel Towan ; Huel Penrose,
near Helston, in pink masses ; Binner
Down ; Cadgwith, in large plates and
thick veins ; Kynance, Lizard Point, and
other parts of the Lizard district, often
in veins ; West Huel Grambler, dog-
tooth spar in masses of quartz and com-
pact fluor, and in skeleton crystals ;
Huel Buller; North Roskear; Pol-
gooth ; Gari as ; Huel Mary Ann, Men-
heniot; Huel Alfred; Tintagel, Bos-
castle, and Delabole ; Beeralstone and
Beerferris, in beautiful pale lilac rhom-
bohedrons ; Huel Friendship ; Babbi-
combe Bay ; Combemartin ; Teignmouth
and Torquay, and many other localities ;
in fissures on the coast ; many mines
near Liskeard, in fine crystals ; in quar-
ries near Beerhead (Beerstone), with
green earth, crystals with brilliant facets,
also massive and compact ; at Exeter, in
an amygdaloidal rock ; Plymouth, in
very fine scalenohedrons and other crys-
tals, like Fig. 222, in cavities in the
limestone rocks ; and many other locali-
ties in the two counties.
b. Schief er Spar. Plymouth, Delabole,
Tintagel, with quartz and albite ; Pol-
gooth ; North Roskear ; Botallack ; Beer-
alstone ; also Derbyshire, Cumberland,
and many other parts of England ; Wales,
Scotland, Ireland, and most other
countries.
Obs. Calcite may be distinguished
from aragonite by its crystalline form,
cleavage, inferior hardness, and sp. gr.,
and by its not falling to pieces when
heated in a matrass. Low hexagonal
prisms, lens-shaped crystals, and tabular
forms are said to prevail in Devon and
Cornwall. Some of the masses of the
pure transparent variety from Iceland
(Iceland Spar) are very large. A
single cleavage rhombohedron has been
observed, more than six yards in
length and three yards high (Dana, Syst.
Min., 1868, p. 679). Chalk, marble, lime-
stone, and oolite are rather rocks than
minerals. Calcite passes into dolomite
from the presence of MgCO3, chalybite
through FeCOs, calamine through ZnCO^.
Above 75 different faces have been de-
scribed, including 41 distinct rhombohe-
drons, 85 scalenohedrons, and seven hex-
agonal pyramids.
A ngles.
R R = 105° 50' c o = 90° 00'
cc' 120 00 eg 116 15
gg 134 57 rr 144 20
Cann. See Fluor.
Capillary. Hairlike, in fine fibres, like
"acicular," but not straight.
Capillary Pyrites. See Millerite.
Capillary Red Oxide of Copper. See
Cuprite (Chalcotrichite).
Carbonate. A compound of a metallic
oxide with carbonic anhydride, or car-
bonic acid in which the hydrogen is dis-
placed by a metal. The mineral car-
bonates have a hardness not exceeding
5, so that they will not strike fire with
steel, nor scratch glass. The anhydrous
carbonates crystallize in the hexagonal
system, and cleave into rhombs with an
angle of 105° or nearly ; rhombic with
prisms of 120° and 60° ; or oblique with
prisms of 105° and 75°. The lustre is
vitreous or pearly, colours very varied.
They are the typical spars. The hydrous
carbonates vary much in crystallization.
All the mineral carbonates when pow-
dered effervesce in strong and warm
HC1. Some effervesce briskly even in a
lump with dilute and cold HC1. The
carbonates found in the two counties
are : —
Calcite,
Dolomite,
Chalybite,
Calamine,
Aragonite,
Cerussite,
Cromfordite,
Diallogite,
Malachite,
Chessylite.
The first eight are anhydrous, the last
two are hydrous.
Carbonate of Copper. See Malachite
and Chessylite.
Carbonate of Iron. See Chalybite.
Carbonate of Lead. See Cerussite.
Carbonate of Lime. See Calcite and
Aragonite.
Carbonate of Lime and Magnesia. See
Dolomite.
Carbonate of Manganese. See Diallo-
gite.
Carbonate of Zinc. See Calamine.
Carnelian. See Chalcedony.
CASSITERITE.
[Oxide of Tin. Tin-stone.] Pyramidal,
like Figs. 61 to 71 and Fis. 77 ; crystals
often imperfect and usually macled, with
some faces striated, rough, or uneven; also
in rolled fragments, or botryoidal with
radiated concentric structure ; massive,
disseminated ; pseudomorphous after f el-
spar, &c.; brittle ; fracture uneven or gra-
nular; semi-transparent to opaque; lustre
resinous ; sub-metallic or adamantine ;
sometimes colourless, but usually grey,
yellow, brown, or black ; streak light
CASSITERITE.
CASSITERITE,
brown or greyish-white ; H. 6-7 ; G.
6 '8-7; some varieties with much iron
6-45.
Var. 1. Diamond- tin is a miner's term
for crystals when of considerable size ;
2. Sparable-tin occurs in small acute
pyramids, almost acicular, like Figs.
65. 66.
3. Rosin-tin is reddish or yellowish,
and semi-transparent.
4. Wood -tin or Fibrous-tin has a con-
centric fibrous structure, colour various
alternating shades of brown.
5. Toad's Eye Tin is a variety of
wood tin, occurring in small spherical
masses embedded in tin of a darker or
lighter tint.
6. Stream-tin is found in rounded
masses, as if waterworn, in many of the
river gravels of Cornwall and Devon.
7. Mine-tin is that which occurs dis-
seminated through, or in veins traversing,
granite or clay slate.
.B., etc. In matrass unchanged, or de-
crepitates only ; on C the same, loses
colour, or is reduced where it touches the
charcoal ; with soda and KCy is readily
reduced to a white malleable bead of Su
in R F ; insoluble in HC1, HNO3, or
Aqua Regia.
Comp. Anhydrous stannic oxide, with
sometimes as much as 10 per cent, of
the oxides of iron or manganese.
The following are analyses of Cornish
specimens : —
a. b. c. d.
Oxide of tin ... 98 "93 96 "26 91 -0 94 '5
Peroxide of iron
& manganese 0'32 3 '40 9'0 1/5
Silica 075 0'75 — 1/0
Alumina — — — 3'0
Totals ... 100-00 100'41 100 '0 100 '0
a. was a specimen from Altarnun, ana-
lysed by Klaproth ; b. was analysed by
Thomson, c. by Vauquelin (the sp. gr.
was 6 '45), and d. by Johns.
With tin 78-67 and oxygen 21 '33 the
formula will be Sn or SnOa.
^ The following percentages of metallic
tin were obtained by means of a charcoal
crucible and blast furnace, by Klaproth,
viz.: —
Light brown acicular
crystals 75 per cent.
Grey crystals from St.
Agnes 74 do.
Wood-tin 73 do.
Stream-tin from La-
dock 76 do.
Stream-tin from Altar-
nun 76 do.
From which it appears that the stream-
tin is even more pure than the grey or
light brown crystals from the mines.
Loc. a. Fine crystal shave been obtained
from Botallack, Huel Owles, and other
St. Just mines (Fig. 65) ; the cliffs north
of St. Just ; Wherry Mine, near Pen-
zance, in the cavities of a chloritic con-
glomerate, cemented with amorphous
cassiterite ; St. Michael's Mount, in the
joints of the granite, with schorl, fluor,
wolfram, and occasionally topaz, garnet,
and beryl; Huel Providence and other
mines near St Ives and Lelant ; Great
Work, Huel Vor, Huel Metal, Great Huel
Fortune, and other mines in Breage ; East
Huel Lovell, Trumpet Consols, and other
Wendron mines ; Huel Tremayne, and
other Gwinear mines, in large macles
(Figs. 69 and 70); Dolcoath, and other
Camborne mines (Figs. 65, 66); Relistian
(Fig. 62); East Pool ; Huel Uny ; Pednan-
drea (Figs. 61, 62, and other forms, some-
times associated with chalcedony); the
United and other mines in Gwennap ; Tre-
vaunance, Polberrow Consols, Huel Tow-
an, Huel Pye, Pell Mine (Figs. 61, 62),
Huel Kitty, and most of the St. Agnes
mines ; Cligga Head ; Beam Mine,
Polgooth, Stenna Gwynn, Goonbarrow,
Minear Downs, and other mines near St.
Austell ; Burthy Mine, St. Enoder, in
small black crystals (Fig. 61) with native
copper ; Huel Maudlin (Fig. 62), Kit
Hill, Callington, in fine black crystals ;
Drakewalls ; Ash burton ; Birch Tor ;
Yeoland Consols ; Buckland Monacho-
rum ; Huel Sidney, Plympton ; Rix Hill,
near Tavistock ; Chagford in granite at
the Morley clay works; Plympton; in
the granite of Dartmoor ; as well as other
places in Devonshire.
b. Sparable-tin (Figs. 65, 66) has been
found in fine crystals at Dolcoath ; Huel
Uny; Pednandrea; Huel Park, St.
Agnes ; Huel Owles, St. Just ; and many
other mines ; in the granite of St.
Michael's Mount, &c.
c. Wood -tin has occurred at Polberrow
Consols; Sancreed, in thick mam millary
concretions capping quartz ; Huel Garth,
near Penzance ; Great Huel Vor, Breage ;
and many of the Cornish stream works.
d. Toad's Eye Tin has been found in large
masses at Tregurthy Moor and Gavrig-
gan, embedded in quartz.
e. Stream-tin has been f oun d in Carnon
and other branches of Falmouth Har-
bour, in large quantities ; also at Gwen-
nap ; Trewarda, Kenwyn ; Ladock ; Al-
tarnun ; Luxulian ; Lanlivery ; Fore
Moors, St. Columb ; Bodmin Moor ; Tre-
sowes, near Ashton in Breage ; St. Bu-
ry an ; Holm Bridge, three miles N.W.
of Buckfastleigh ; Sigford and Yarnour
Wood, near Ilsington ; Warren Tor ;
CASSITERITE.
CELESTITE.
25
Monk's Hill, Plaster Down, near Samp-
nird Spiney ; Axtown ; the Teign, the
Bovey, West Dart, and many other
streams in the "Western part of Devon-
shire. Cassiterite has also been found
in France, Spain, Germany, Sweden,
Finland, Greenland, the United States,
Mexico, Chili, Peru, Sumatra, Banca,
Australia, &c.
Large pseudomorphous crystals of cas-
siterite after felspar occurred formerly
inconsiderable abundance at HuelCoates,
St. Agnes, some were like Fig. 179, but
more compressed, others were macled.
Many of the larger crystals "presented
the curious circumstance of shewing the
original felspar replaced by oxide of tin
only about half across longitudinally."
Similar pseudomorphs have been found
at Carn Brecon, St. Mewan, near St.
Austell; and also, about ten years ago,
at Balleswidden, St. Just, by Mr.
Richard Pearce.
The silicate of tin described by J.
Garby is, perhaps, a pseudomorph after
quartz. Some occurred about 1820 as an
impalpable powder, or compact; yellow-
ish-grey in color, and composed of 53*0
per cent, of oxide of tin and 46 per cent,
of silica According to Mr. J. Mich ell,
some of the " silicate of tin was in hex-
agonal prisms, much like quartz, but
with the summits always wanting."
Obs, The English crystals of cassi-
terite are usually small and ^bright ;
foreign crystals are often large and dull.
Most of the tin stream works have
yielded small quantities of gold from
time to time. Wood-tin is said by
Messrs. Greg and Lbttsom to have been
found about the year 1858 " in walls by
the roadside, in fragments nearly as
large as a man's head, the surface water-
worn frequently, and often exhibiting
that peculiar distribution of colour in
superimposed bands of various shades
of brown and yellow, from which this
variety derives its trivial name."
Cassiterite is usually found in veins
traversing granitic, schistose, or porphy-
ritic rocks, and associated with quartz,
fluor, schorl, chlorite, wolfram, mis-
pickel, oxides of iron, pyrites, blende,
and ores of lead and copper. It is
harder and has a much lighter streak
than wolfram, and has no cleavage,
which in wolfram is always a well
marked character. It is much harder
than blende, and much heavier than
garnet, schorl, or idocrase. Figs. 61 to 71
and Fig. 77 are all Cornish and Devon-
shire forms. Macles are commonly joined
by the face e ; the faces 1, k, r, Ji, M,
O are often rough or uneven ; a and e
are sometimes striated parallel to their
intersections with each other. M is also
sometimes striated.
Angles.
M M = 90° 00' M z = 155° 00'
OM 90 00 Oz 112 25
a a 90 00 ss 121 40
My 119 43 ss' 87 07
M s 133 34 k k 163 00
M i 157 11 e e' 67 50
Ml 175 10 zz' 118 18
M k 171 30 z z 159 06
Me 113 15 Mr 168 41
Ma 135 00
CELESTITE.
[Celestine.] Rhombic ; the crystals
much resembling those of Barytes and
Anglesite ; often in tabular crystals,
much like Figs. 130, 131, 132 ; some
planes striated or rough; perfect basal
cleavage parallel to O, less perfect cleav-
ages parallel to M and M' ; also compact,
massive, fibrous, granular, earthy ; brit-
tle ; fracture imperfectly conchoidal or
uneven ; transparent to translucent ;
vitreous to pearly ; colourless, or white,
grey, bluish, or reddish ; sometimes
pleochroic ; streak white ; H. 3-3 '5 ; G.
3 '8-4; pyrophosphoric.
E., etc. In matrass often decrepitates;
on C fuses at 3 to a white pearly bead,
colouring the flame carmine red, espe-
cially after being exposed to the R F and
then treated with HC1 ; with soda melts,
and sinks into the charcoal ; with borax
melts to a clear glass, which is opaque
and yellowish or brownish when cold;
insoluble in acids ; soluble in HC1 after
exposure to the R F, the solution mixed
with alcohol burns with a bright red
flame.
Comp. Anhydrous sulphate of Strou-
tia. No analysis of a specimen from the
West of England is known, but foreign
varieties contain from 40 to 46 per cent,
of sulphuric anhydride, and 51 to 58 per
cent, of strontia. With 43 '6 of sulphuric
anhydride, and 56 '4 of strontia the for-
mula will be SrS or SrSO^ or SO2Sro".
Loc. Binner Down Mine, four miles
north of Helston ; Sidmouth, and other
places on the south coast of Devonshire,
in fissures of the cliffs, in thin crystalline
transparent plates on gypsum, and in the
cavities of flints ; also Somersetshire,
Gloucestershire, Yorkshire, Northum-
berland, Wales, Scotland, France, Spain,
Italy, Germany, Hungary, North Ameri-
ca, &c.
Obs. The name celestite is derived
from coalestis — sky blue— this colour is
not, however, characteristic of the species,
26
CELLULAR
CERVANTITE.
but in some instances at least is due
to the presence of a minute proportion
of phosphate of iron.
A ngles.
P M = 90° 00' P d = 140° 35'
PM' 90 OC Po 127 56
MM' 104 02 PI 151 17
Cellular. When a mineral is full of
small cavities or hollows it is termed
"cellular; if the cavities are somewhat
spherical, the term "vesicular" is used.
Sometimes these hollows are large, and
filled with matter of a different kind and
colour, giving rise to the "amygda-
loidal " structure. Pumice and Calamine
are often cellular.
Cellular Pyrites. A cellular variety
of bisulphide of iron, usually of marca-
site.
CERUSSITE.
[White Lead Ore.] Rhombic; in
prisms ; often acicular and laterally ag-
gregated ; sometimes stellate or tabular
(Figs. 140, 141, 142); sometimes a dis-
tinct cleavage parallel to M, the face a.
usually striated, O rough ; sometimes
massive, compact, fibrous, or earthy ;
brittle ; fracture conchoidal or uneven ;
transparent to translucent; with power-
ful double refraction ; lustre resinous,
adamantine, or pearly ; colourless, white,
grey, greenish, or bluish, from the pre-
sence of a trace of copper, or sometimes
with a dark brown or black tarnish ;
streak white ; H. 3-3 '5 ; G. 6 '4-6 '5.
B., etc. In matrass decrepitates, turns
yellow, and at a high temperature red,
but becomes yellow again on cooling,
sometimes phosphoresces ; on C decre-
pitates, fuses at 1, and is readily reduced
to a malleable bead of metallic lead,
depositing a yellow incrustation on the
charcoal; insoluble in HC1, but readily
soluble in dilute HNO3, with efferves-
cence.
Gomp. Anhydrous carbonate of lead.
No analysis of a specimen from the
West of England is published. Foreign
specimens are often pure. With oxide
of lead 83 '5, and carbonic anhydride
16'5 the formula will be PbC or PbCO3
or COPbo".
Loc. Pentire Glaze and St. Minver,
in very thin snow-white tables (some of
the crystals from Pentire Glaze were 10
inches long), and in fine needles ; Huel
Rose and Huel Penrose, near Helston,
in delicate acicular prisms on Limonite ;
Huel Alfred ; Huel Golden ; Huel Ann ;
Great Retalkck, West Chiverton, and
other mines in Perranzabuloe ; Huel
Ptose, Newlyn ; Huel Confidence ; Huel
Crenver ; Huel Primrose and Park Mat-
thews, near St. Austell ; East Tamar, in
fine colorless crystals, with Anglesite,
in decomposed galena ; Hennock, near
Chudleigh, in small acicular crystals ;
Beeralston ; also Derbyshire, and other
parts of England ; Scotland, Wales, Ire-
land, France, Tyrol, Poland, Siberia,
United States, &c.
Obs. It may be readily distinguished
from all minerals that at all resemble it
by its ready effervescence with dilute
HNO3 and its easy reduction on charcoal.
Angles.
M M = 117° 31' O y = 149° 21'
MO 90 00 pp 130 00
Ob 90 00 pp' 108 98
ab 90 00 kk 71 44
Ma 121 24 ii 110 40
Mi 145 20 ar 151 22
Mk 125 52 ai 145 10
CERVANTITE.
[Antimonial ochre in part.] Rhombic (?)
in acicular crystallizations ; also earthy,
pulverulent, investing, massive, or dis-
seminated ; brittle or friable ; opaque ;
lustre greasy or pearly, glimmering or
dull ; yellowish or reddish-white to yel-
low ; streak the same, but usually
lighter, and shining ; soft and friable";
(Dana says H. 4-5 ;) G. 4-4 1.
B. , etc. In matrass gives a little water,
and with a strong heat a faint white sub-
limate ; on C is easily reduced to a grey
brittle bead of antimony, coating the
charcoal with white, and tinging the
oxidising flame green ; soluble in HC1,
the solution is sometimes partly precipi-
tated by the addition of water.
Gomp. Anhydrous binoxide of anti-
mony, or else a mixture of antimonious
and antimonic oxides. No analysis of a
British specimen is known, but foreign
specimens contain from 67 to 79 per cent.
of antimony, and 16 to 20 of oxygen,
with generally a little water of absorp-
tion. With antimony 79 '2 and oxygen
20'8 the composition will be Sb or SboO,
+ Sb205-
Loc. Near St. Minvers ; Huel Lea,
on the Tamar ; Huel Kine ; Huel Boys,
near Padstow ; Port Isaac ; Endellion ;
Trevinnock ; Swanpool, near Falmouth ;
also France, Spain, Germany, Hungary,
Mexico, &c.
Obs. It usually accompanies ores of
antimony, and is sometimes pseudomor-
phous after antimonite.
Chalcedony. See Calcedony.
CHALCOCITE.
GHALCOPHYLLITE. 27
CHALCOCITE.
[Chalcosine. Copper Glance, R*ed-
ruthite. Vitreous Copper.] Rhombic ;
in regular six-sided prisms, usually short
and modified terminally ; also obtuse
six-sided pyramids ; often macled, with
the face O striated (Figs. 100 to 107);
usually massive, lamellar, or compact ;
sectile or almost malleable ; fracture
conchoidal, even, or uneven ; opaque ;
lustre metallic, brilliant to glimmering ;
blackish lead-grey, often a black or iri-
descent tarnish, or coated with green
carbonate ; streak greyish-black ; H.
2-5-3; G. 5-5-5-8.
Var. Nail-headed eopper ore is a
macled variety (Fig. 104), so called from
its resemblance to the heads of some
nails.
B., etc. In matrass gives a slight
white sublimate ; on C fuses at 1, tinges
the flame blue, gives off vapours of sul-
phurous anhydride, and emits sparks ;
with soda or alternate OF and RF
yields a bead of metallic copper, leaving
usually a little black infusible magnetic
slag ; decomposed by HNOs.
Gomp. Anhydrous subsulphide of
copper. The following is an analysis of
a specimen from the United Mines,
Gwennap, by Thomson : —
Copper 7716
Sulphur 20-62
Iron 1-45
Total 99-23
With copper 79 '8 and sulphur 20 '2 the
formula will be Cu2S.
LOG. Fine crystals, formerly at Levant
(Figs. 100, 102); Botallack (Fig. 102); St.
Ives Consols, in very fine crystals, lately
like Figs. 104, 107, 108 ; Huel Crenver ;
Huel Abraham, in thin hexagonal plates,
nail-headed copper, arborescent, and
most of the forms 100 to 106 ; Camborne
Vean; Cook's Kitchen (Fig. 116); Dol-
coath, iridescent; Huel Fanny and North
Huel Basset, in fine elongated and very
perfect crystals ; Huel Buller and other
mines. Massive at most of the copper
mines in Cornwall, especially Botallack,
Spearn Moor, Levant, Ding Dong, Huel
Neptune, and in an elvan course near
Polgooth; Huel Betsy and other mines
in Devonshire, in small quantities ; also
Yorkshire, Scotland, Ireland, Norway,
Sweden, Germany, Siberia, North and
South America, &c.
Obs. It may be distinguished from
Fahlerz by its sectility and grey streak ;
from galena by the absence of cleavage
and sectility ; from pyrargyrite by jits
streak ; from argentite by its blowpipe
reactions ; from Bournonite by its sec-
tility ; and from fntimonite by its blow-
pipe reactions. All the Figs, from 100
to 107 represent forms which have oc-
curred in Cornwall or Devon.
Angles.
O M = 90° 00' Op- 117° 24'
Ob 90 00 MM' 119 35
Oa 90 00 dd' 125 38
Od 117 16 PP 126 54
O e 147 06 pa 116 32
Oz 147 16 Ma 120 12
Ov 136 03
Chalcolite. See Torbernite.
CHALCOPHYLLITE.
[Tamarite. Copper Mica. Rhom-
boidal Arseniate of Copper.] Hexago-
nal, in thin tables, like Fig. 201, with
perfect cleavage parallel to O, or foliated
masses, or druses ; sectile, flexible ; trans-
parent to translucent; lustre adaman-
tine, vitreous, or pearly ; various shades
of green ; streak light green ; H. 2 ; G.
2-4-2-7.
B.i etc. In matrass decrepitates,
yields much water, turns dark green to
black, and with a strong heat deposits a
white or straw-coloured sublimate ; on
C decrepitates, turns black, colours the
flame blue or greenish, melts to a white
globule of metallic appearance; with
RF yields a strong garlic odour ; with
soda a bead of copper ; soluble in HNO3,
and partially in ammonia.
Comp. Hydrated arseniate of copper
and alumina.
The following are analyses of speci-
mens from Cornwall, some, probably all,
from Huel Gorland : —
a. b. c. d. e.
Oxide of Cop-
per 58-00 52-92 52-30 4676 45 '51
Arsenic an-
hydride .. 21-00 19-35 21-27 15 '49 15 '58
Alumina.... — 1'80 213 5 '69 6 '25
Oxide of iron — — — 0'60 0'61
Phosphoric
anhydride. — 1'29 1-66 —
Water 21'0023-9422-58 31 '46 32 '05
Totals . . 100-00 99-30 99 '84 100 '00 100 '00
Sp. Gr.. 2-54 2 '659 2 -659 2 '44 2 "44
a. was analysed by Chenevix ; b. and c.
by Damour; d. and e. are recent and
very careful analyses by Church. With
oxide of copper 58 "8, arsenic anhydride
21*2, and water 20'0 the formula may be
written 8CuAs2+12H2or 3CuO, As2O5 +
5CuH2Oo + 7H2O or As2O2Cuo"3 + 5CuHo2
+ 7OH2; this agiees pretty well with
the analysis of Chenevix. With oxide
of copper 53 "6, arsenic anhydride 23 "1,
and water 24 '3 it may be 8CuAs2 + 14H2
28 CHALCOPYEITE.
CHALCOPYEITE.
or 3CuO As2Og + 5CuH2O2 + 9H.,O or
As2O2Cuo"3+5CuHo2 + 9OH2 ; this agrees
somewhat more nearly with the analyses
of Damour. With oxide of copper 45 '39,
alumina 7 '35, arsenic anhydride 16 '42,
and water 30 '84 the formula may be
SCuAloAso 24H2 or Cu3(AsO4)25H2O +
5CuH2O2 + A1oH6O6 or As2O2Cuo"3 +
5Cu Ho2 + Al2Ho6 + 50H2. WitlToxide of
copper 44 '82, alumina 7 '26, arsenic an-
hydride 16 '21, and water 31 '71 the for-
mula may be 8CuAl2Aso25H2 or Cu3
(AsO4)26H2O + 5CuH2O2 + A12H6O6 or
As2O2Cuo"3 + 5CuHo2 + Al2Ho6 + 6OH2.
Both these formulse agree very closely
with the analyses of Professor Church,
and either of them may be taken as the
correct one, since they only differ by one
equivalent of water. Nearly half the
water may be separated by drying in
vacuo (hygroscopic moisture), while the
rest is not driven off at 100°C (com-
bined water).
LOG. Huel Gorland, Huel Muttrell,
Huel Unity, Ting Tang, and other mines
in Gwennap, but not recently ; Huel
Tamar (whence Brooke and Miller's
name of Tamarite), Gunnislake ; also
Germany and Hungary.
06s. Specimens may, perhaps, be ob-
tained by carefully turning over the old
burrows in copper mining districts.
"The specimens which have been ob-
tained lately are not so well crystallized
as those which were raised formerly,
neither do they equal them in colour :
being of a pale verdigris green." (Greg
and Lettsom, p. 316, 1858.)
Chalcophyllite occurs associated with
other ores of copper, and is sometimes
altered to Chrysocolla. It may be dis-
tinguished from Torbernite by its strong
arsenical blowpipe reactions.
A ngles.
R R' = 110° 12' e o = 124° 09>
R' o 108 44 v o 124 09
v truncates the edge R' o.
CHALCOPYRITE.
[Towanite. Copper Pyrites. Yellow
Copper Ore.] Pyramidal ; in more or less
modified sphenoids, with e. p. striated,
rough, or uneven ; the sphenoid is very
near a tetrahedron : often macled (Pigs.
79 to 85) ; also stalactitic, botryoidal, or
mammilated ; usually massive, compact,
lamellar, ordisseminate ; britfcleor almost
sectile ; fracture conchoidal or uneven ;
opaque ; lustre metallic, brilliant to glim-
mering ; brass yellow, often with an
iridescent tarnish ; streak greenish-
black ; scratch, bright yellow and shin-
ing; H. 3-5-4; G. 4 1-4 "3.
Var. Blistered copper is a botryoidal
variety ; peacock copper is a massive
variety, with blue, red, green, brown, or
iridescent tarnish, and often a lamellar
structure.
B , etc. In matrass sometimes decre-
pitates, gives a yellow sublimate ; on C
melts to a black brittle magnetic glo-
bule ; with soda and a little borax in
R F gives a bead of copper ; decomposed
by HC1, forming a green solution and
leaving yellowish powdery sulphur.
Comp. Sulphide of copper and iron.
The following are analyses of Cornish
specimens : —
a, b. c. d.
Copper 30-00 31 '20 3015 30 '00
Iron 32-20 30'80 32'37 31 '00
! Sulphur ... 3516 34 "46 35 '34 33 '00
Silica 2'64 110 3'00
Lead, arse-
nic, loss, &c. — 2-44 214 300
Totals ... 100 00 lOO'OO 100 '00 100 '00
a., b., c were analysed by Phillips, a.
and c. being crystallized, b. botryoidal;
d. was a specimen from Huel Towan,
analysed by Michell. With sulphur 34 '9,
copper 34 '6, and iron 30'5 the formula
may be written Cu2S + Fe2S3 or Cu2S +
FeSfFeS2or CuFeS*.
Loc. Crystallized, East Pool, with cha-
lybite, in sphenoids scarcely distinguish-
able from Fig. 33 ; Cam Brea. iridescent,
on cubes of fluor ; Tincroft ; Dolcoath ;
Huel Tolgus, in obtuse rhomboids (pseu-
domorphous after dolomite?) ; Huel Bul-
ler, in very perfect sphenoids of one inch
or more ; Huel Towan, St. Agnes ;
Alfred Consols, Hayle, in very perfect
rhombic dodecahedrons (Greg and Lett-
som, 340), perhaps pseudomorphous after
blende or erubescite ; St. Just, in fine
curved rhomboids (pseudomorphous after
dolomite?); Levant Mine, pseudomor-
phous after Fahlerz ; Herodsfoot, in
double pyramids of three-quarters of an
inch ; Virtuous Lady Mine, in beauti-
fully iridescent and large sphenoids ;
Ashburton ; Huel Franco ; Buckland
Monachorum ; Huel Robert ; Sampford
Spiney ; Devon and Courtenay ; Devon
Great Consols ; Huel Friendship; Wills-
worthy Mines ; Copper Hill, Fursdon
j Manor, and other mines near Okeharnp-
' ton ; Combemartin, North Moulton,
Molland, Lundy Island, &c. ; and other
copper mines in the two counties.
Blistered Copper Ore.- Cook's Kit-
chen ; Huel Basset ; Dolcoath ; Ale and
Cakes ; and other localities.
Massive and Iridescent (Peacock Cop-
per Ore). —The United Mines, Gwen-
nap ; Gunnislake ; Great Criunis ; South
CHALCOSINE.
CHALYBITE.
29
Caradon ; Virtuous Lady ; Devon Great
Consols, and many other mines, often
associated with chalybite, blende, and
cassiterite; also Cumberland, and several
other English counties ; Wales, Scot-
land, Ireland, Germany, Italy, Spain,
Siberia, the United States, South
America, Africa, Australia, &c.
obs. It may readily be distinguished
from pyrites and marcasite by its infe-
rior hardness, from erubescite by its
yellow scratch ; from gold by its brittle-
ness. A variety is described b/ Mr. John
Garby as occurring near Gwinear — "fine-
grained, white streak, pale yellow colour,
20 per cent, only of copper, and sufficient
silver to pay for extraction." Another
white variety from Huel Gorland, in
Gwennap, yielded 40'0of copper, besides
iron, arsenic, and sulphur ; it occurred
with ordinary chalcopyrite.
Angles.
P P = 70° 07' a a = 90° 00'
PP' 109 53 cd 140 47
PC 125 40 ex 155 05
Pa 125 03 cv 152 33
P z 140 20 c z 116 54
PI 144 20 zz 101 50
me 90 00 vx 148 06
Chalcosine. See Chalcocite.
Chalcotrichite. See Cuprite.
CHALYBITE.
[Siderite. Spathose Iron.] Hexagonal,
in small obtuse or acute rhombohedrons,
or lenticular, occasionally in hexagonal
prisms (Figs. 195, 199, 202, 217, 220, 221,
224, 225, 231), often macled; cleavage
rhombohedral, (R) perfect, often curved ;
some of the faces striated, rough, un-
even, or curved ; also massive, granular,
lamellar, or compact ; sometimes reni-
form or botryoidal ; brittle ; fracture
subconchoidal or uneven ; translucent to
opaque; lustre adamantine, pearly, or
silky, brilliant to glimmering ; yellowish-
white to dark-brown ; often a dark tar-
nish from exposure to light; streak
white, yellowish, or brownish; H. 3'5-
4'5; G. 3 -7-3*9; sometimes feebly mag-
netic.
Var. Wood Iron is a fibrous variety,
of brownish colour and silky lustre.
Sphaerosiderite is a nodular, concre-
tionary variety.
Slipper Iron is a pseudomorphous
variety, which occurs in forms somewhat
resembling a lady's slipper.
Clay Iron-stone is an argillaceous mas-
sive variety, rather a rock than a
mineral.
Black Band is the same, but with a
considerable mixture of carbonaceous
matter.
B., etc. In matrass turns very dark
and magnetic ; on C the same ; infusible ;
with borax or micro, gives Fe reactions ;
the powder is slowly soluble with effer-
vescence in HC1 or HNO3.
Comp. Anhydrous carbonate»of iron,
with often a part of the iron replaced by
Mn or Ca. No analysis of a specimen
from the West of England is known, but
a specimen from Durham gave— Oxide
of iron 54 '57, oxide of manganese 151,
lime 318, carbonic anhydride 35 '90.
With oxide of iron 621 and carbonic an-
hydride 37 '9, the formula would be FeC
or FeCO3 or COFeo".
Loc. Fine crystals at Huel Maudlin,
near Lostwithiel (Figs. 195 and 202), also
pseudomorphous after fluor; Huel Boul-
ton, in six-sided prisms ; Charlestown
United, and other mines near St. Aus-
tell, very perfect and iridescent ; Crinnis
Mine, with drusy childrenite ; Fowey
Consols, in forms approaching to the
octahedron (Fig. 224), tabular (Fig. 202),
and crystals like Fig. 221, rich brown,
translucent, and the faces slightly
curved ; near Bodmin, in hexagonal crys-
tals, more than one inch long, like Fig.
195, attached to quartz ; Bucker's Mine
(Fig. 217) ; Dolcoath ; Cook's Kitchen, East
Pool and other mines in the neighbour-
hood of Camborne, and many other mines
in Cornwall and Devon ; Carny worth and
Huel Owles (Fig. 220 and other forms);
Botallack, in brown rhomboids, like Fig.
119 ; Virtuous Lady, Huel Betsy, Huel
Crebor, and Bedford United Mines, in
fine spheroidal groups, made up of curved
tabular crystals, of a rich hair-brown
colour ; Ivy Bridge, on quartz ; Beeral-
stone, lenticular.
Wood Iron. — East Pool, Tincroft,
Cook's Kitchen, Huel Buller, Huel Beau-
champ, and other mines near Camborne
and Kedruth ; East Crinnis, and other
mines near St. Austell.
Sphaerosiderite. — Madron, near Pen-
zance, and Mount Mine, near Marazion,
in botryoidal masses resembling calamine.
Massive and compact. — HuelKose and
Huel Penrose near Helston ; at Perran-
zabuloe ; at the railway cutting near
Plympton, of a beautiful white colour ;
Exmpor, and Combemartin, and other
localities in the two counties ; also many
parts of England, Scotland, Wales, Ire-
land, Fra'nce, Spain, Italy, Germany,
Poland, United States, South Ame-
rica, &c.
Pseudomorphs. — The "Slipper Iron"
found at Virtuous Lady, Bseralstone,
and Huel Friendship is probably pseudo-
morphous after selenite. At Virtuous
Lady hollow cubes of chalybite are also
30 CHENEVIXITE.
CHESSYLITR
found, from a very small size to three or
four inches square ; these are probably
casts of fluor. In the interior «f these
" boxes," as they are called by the
miners, fine crystals of chalcopyrite are
sometimes found, together with beautiful
froups of opaque white quartz crystals.
n one instance this peculiar form of
chalybite has been observed as a coating
to a cube of fiuor. At Beeralstone the
chalybite occurs pseudomorphous after
calcite.
A specimen of chalybite, almost che-
mically pure, was found by Mr. Wm.
Vicary in the interior of a large flint
near Haldon. It was a globular crystal-
line mass, of radiated structure and
yellowish-grey colour.
Obs. Chalybite may be distinguished
from childrenite by its inferior hardness,
different crystalline form, and usually the
absence of any reactions for phosphoric
acid before the blowpipe ; from calcite
and dolomite by its becoming black and
magnetic when heated in a matrass. The
massive varieties often contain some
phosphoric acid.
Angles.
RR = 107° 00' bb' = 120° 00'
Ro 136 37 w 144 56
ee 136 34 v v' 105 15
mm 66 18 v v" 134 40
ss 64 10 vo 121 25
so 101 57 ba 150 00
oe 154 43 Rv 150 45
o m 104 49 f f 80 06
oa 90 00 ou 163 00
a a' 120 00 of 117 53
f is a rhombohedron of 80° 06', and
truncates the angle e' a ; u forms a rhom-
bohedron of about 120° and truncates
ss. Besides Figs. 195, 199, 202, 217,
220, 221, 224, 225, 231, the following
forms and combinations have all been
found in Cornwall or Devon, viz., — f, s,
fa, a o, R o, R a O, R m f , R o u,
Rose, Raose, Raoe, Rsb, Rv,
Rvb, Raofe.
Chemical Characters of Minerals.
Those which depend upon their chemi-
cal composition, as taste, odour, solubi-
lity, fusibility, and the reactions with
soda, borax, and micro.
Chemical Equivalents. See Table of
the Elements in part 1.
CHENEVIXITE.
Massive ; compact ; opaque ; vitreous ;
dark dull green, passing into yellow;
streak yellowish-green: H. 4 '5: G.
3-93 (?)
B., etc. In matrass decrepitates, gives
off water, and turns brown ; on 0 fuses
easily to a black magnetic scoria, giving
off arsenical fumes; easily soluble in
HC1 or HN03.
Comp. Hydrated arseniate of iron
and copper. Analyses : —
a, b.
Arsenic anhydride 33 '50 ... 32 '20
Oxide of copper 22'50 ... 3170
Oxide of iron 27 '50 ... 2510
Phosphoric anhydride... — ... 2 '30
Lime — ... 0'34
Water 12'00 ... 8'66
Totals 95-50 ... 100'30
Both were Cornish specimens, a. was ana-
lysed by Chenevix, b. by Adam, recently.
With arsenic an hydride 34 '2, oxide of cop-
per 29-9, oxide of iron 26 '9, and water 9'0
the formula may be written 2As25Cu5Fe
8H2 or (As2O2)2Cuo"3Feo"3 + CuHo2FeHo2
+ 4OH2 or 3CuOAs2O5 + 2CuH2O2=3FeO
AsaO5 + FeH2Oa + 4H2O.
Loc. Cornwall, in small compact
masses, so imbedded in quartz rock that
it is not possible to separate them com-
pletely.
Obs. Probably specimens might be
found by a careful examination of old
collections.
Chenocoproiite. See Pitticite.
GHESSYLITE.
[Azurite. Lazulite. Blue Malachite.
Blue Copper.] Oblique ; crystals usu-
ally small and short prismatic or
tabular (Fig. 154), with striated or rough
faces ; also botryoidal, stalactitic, in-
vesting, disseminate, massive, compact,
earthy ; brittle ; fracture conchoidal,
uneven, or splintery ; vitreous to adaman-
tine ; deep blue ; streak blue, lighter
than color; H. 35-4 ; G. 3'5-3'8.
B., etc. In matrass decrepitates, turns
black, and gives off water ; on C fuses
and yields a bead of copper; soluble
with effervescence in HC1 or HNO3,
more slowly in ammonia.
Comp. Hydrated carbonate of copper.
No analysis of a British specimen is pub-
lished, but a specimen from Chessy
yielded — Oxide of copper 69 '09, carbonic
anhydride 25 69, water 5 '22, which agrees
with the formula? 3Cu, 2C, H2 or 2CuCO3
-f CuH2O3 or 2COCuo" + CuHo2.
Loc. Huel Gorland, Huel Unity,
Huel Virgin, Ting Tang (prettily crys-
tallized), Carharrack, all in Gwennap ;
Huel Muttrell, Huel Mill Pool (once,
crystallized); Huel Buller, near Red-
ruth (Fig. 154 and P s h 1 the faces h
predominating); and in small quantity
in most of the Cornish copper mines;
CHILDRENITE.
CHLOEITR
31
East Tamar, near Beerferris, in good
crystals ; Devon Great Consols, and
other copper mines in Devon ; also
at Chessy, near Lyons, where the
best crystals have been obtained ; Thu-
ringia, Moldavia, Ural, Siberia, United
States, &c.
Obs. Chessylite is usually found
lining cavities in the older rocks, with
malachite and cuprite. It is, perhaps, a
decomposition product. When abundant
it is ground up for use as a pigment.
A ngles.
MM = 99° 32' P h ~ 111° 46'
M0 57 11 PM 91 48
11 119 16 P0 132 50
hh 106 14 Ps 135 13
The more common British forms are
Phi, Phis, and Fig. 154.
Chiastolite. See Andalusite.
CHILDRENITE.
[Rhombic ; in small modified pyra-
mids, like Fig. 146, or tabular crystals,
like Figs. 143, 144, 145 ; or druses; frac-
ture uueven ; translucent ; vitreous to
resinous, brilliant ; yellowish or brown-
ish ; streak pale yellowish-brown ; H.
4'5-S; G. 3'2.
B., etc. In matrass gives off water,
which does not usually affect test paper;
on C is infusible, or swells up and fuses
on the edges to a dark mass, and colours
the flame bluish-green ; with borax and
micro, gives the Fe and Mn reactions ;
the powder slowly soluble in HC1.
Comp. Hydfated phosphate of iron,
alumina, and manganese, as appears
from the following analysis of a Cornish
specimen by Rammelsberg ; —
Phosphoric anhydride 28 *92
Alumina 14'44
Oxide of iron 30'68
Oxide of manganese 9'07
Magnesia 0'14
Water .., 16 '98
Total 100-23
With oxide of iron 29 '3, oxide of manga-
nese 9 '6, alumina 14 '0, phosphoric anhy-
dride 29'1, and water 18 '0 the formula
may be 6Fe 2Mn 2A12 3P2'-!-15H2O or
P3O(Al2ovi)2Fep"6Mno"2 + 15OH2.
LOG. Crinnis Mine, near St. Austell,
on slate, sometimes with apatite, in small
distinct crystals, like Fig. 146 ; Huel Cre-
bor, in distinct crystals, like Fig. 143, em-
bedded in greyish -green chloritic earth ;
George and Charlotte Mine, Tavistock,
in large and brilliant crystals, like Fig.
145, some one inch in length, on quartz,
chalybite, and pyrites j Devon and Corn-
wall United Mines. It occurs also in
Cumberland and the United States.
Obs. It may be mistaken for chaly-
bite, but may be distinguished by its
crystalline form and superior hardness.
Angles.
O r =* 109° 53' s s' = 130* 04'
Os 114 58 ss 102 41
On 142 07 nn' 75 46
Oa 152 22 rn 139 08
Oo 90 00 rs 168 29
rr' 119 32 sn 137 26
China Clay. See Kaolin.
China Stone. This is a decomposed or
imperfectly formed white granite, abund-
ant in the neighbourhood of St. Austell,
Breage, St. Day, and other places in
Cornwall. It is used for making the
finer kinds of pottery.
Chloanthite. See Smaltite.
Chloride of Silver. See Kerate.
Chloride of Sodium. See Halite.
Chlorides. Salts composed of a metal
in union with chlorine. All the chlorides,
except those of silver, lead, and mer-
cury, are readily soluble in water, and
have a distinct taste. From their solu-
bility they are not common as minerals,
with the exception of Rock Salt or
Halite. The chlorides found in the two
counties are —
Kerate, Botallackite,
Halite, Tallingite,
A tacamite, Cromfordite^
Cromfordite is a chloro-carbonate. Ata-
camite is an oxy-chloride.
CHLORITE.
[Prochlorite. Dana.] Hexagonal ;
crystals very rare ; usually thin hexago-
nal plates, often grouped together in
rosettes ; cleavage basal, rery perfect j
massive ; foliated, the f oliae flexible, but
scarcely at all elastic ; generally scaly,
compact, or earthy; investing, pseudo-
morphous, or disseminated ; sectile ;
fracture earthy or slaty ; unctuous ;
semitransparent to opaque; lustre pearly
or sub-metallic ; shining or dull ; various
shades of green, sometimes blue, greyish,
yellowish , or brown ; crystals dichroic ;
streak white, or like the colour, but
paler; H. 1-2; G. 2'7-3'0.
B.j etc. In matrass gives off water,
becomes lighter in colour ; on C fuses
at 5 (?) to a magnetic mass, which, with
borax and micro., gives iron reactions ;
in the forceps glows with a bright light,
but is scarcely fusible ; insoluble in HC1
or HNO3. Partly soluble in warm con-
centrated H2SO4.
Comp. Hydrous silicate of alumina,
magnesia, and iron. No analysis of a
32 CHLOEOMELANE.
CHONDRODITE.
British specimen is published, but foreign
specimens yield from 25 '0 to 28 '0 per
cent, of silica, 14 '5 to 22'0 of alumina,
15'0 to 29-0 of oxide of iron, 13 '0 to 31 '0
magnesia, 90 to 14*0 of water. With
silica 26'9, alumina 19 '8, oxide of iron
27 '6, magnesia 15 '3, water 10 '4 the for-
mula may be 6Fe 6Mg 3A12 7Si 9H2
(oxygen ratio for R R2 Si H2 =12 : 9 : 14 : 9.
for bases and silica 3:2) or (4-7ths Mg
Fe)3+(3-7ths Al2)Si+4-3rdsH2 or Si7O2
(Al2Ho6)3Feo"?Mgo"6.
LOG Chlorite occurs in most of the tin
mines of the two western counties. At
Virtuous Lady Mine it often contains
fine crystals of mispickel, and sometimes
small crystals of anatase and brookite ;
at Cam' Brea, Great Huel Vor, Huel
Prospidnick, and other mines it contains
beautiful striated cubes, and pentagonal
dodecahedrons of pyrites disseminated
through it ; at New Rosewarne, near
Gwinear, it occurs in foliated and ra-
diated masses, with quartz, killas, brec-
cia, and sometimes cassiterite, and also
in the form of a "cap" on quartz crys-
tals. At Wherry Mine, near Penzance, a
conglomerate of chlorite pebbles, ce-
mented by oxide of tin, contained pure
crystals of tin. In some of the mines
near St. Day small crystals of fluor are
found embedded in chlorite ; at Botal-
lack it sometimes contains small parti-
cles of cobaltite. It occurs pseudomor-
phous after felspar in much of the gra-
nite to the south and west of Carnmarth ;
at the Consolidated Mines in the form of
albite ; at North Roskear, in pseudomor-
phous octahedrons, perhaps after fluor ;
on Dartmoor and at St. Just, in the
form of axinite ; at Tresavean, in octa-
hedrons, perhaps after magnetite. It
also occurs in Cumberland, Westmore-
land, Wales, Scotland, Ireland, Ger-
many, Tyrol, and most mining countries.
O6«. Chlorite often contains disse-
minated crystals of pyrites, hornblende,
magnetite, fluor, quartz, and sometimes
garnet. In Cornwall it is known as
"Peach," and is especially associated
with cassiterite.
Chlorocarbonate of Lead. See Crom-
fordite.
Chloromelane. See Cronstedtite.
CHLOROPAL.
[Nontronite. Pinguite. Gramenite.]
Amorphous, massive, compact, opaline
or earthy ; fragile ; fracture conchoidal,
splintery, or earthy; opaque to sub-
translucent ; resinous to dull ; green or
yellowish-green ; H. 0 to 4'5 ; G. 1'7-2'1.
Var. 1. Chloropal. H. 2 '5-4 '5 ;
meagre ; adherent ; brownish or yellow-
ish-green.
2. Nontronite. H. 2 '5-4 '5; yellow or
greenish ; unctuous.
3. Pinguite. H. 0-1 ; green ; non-
adherent.
4. Gramenite. Fibrous or feathery,
grass-green.
-B., etc. In matrass gives off water and
becomes darker ; on C infusible ; turns
black and magnetic ; with borax and
micro, gives the reactions for iron and
silica. Chloropal is partly decomposed
by HC1. Pinguite is completely decom-
posed with separation of powdery silica.
Nontronite is decomposed, and deposits
gelatinous silica.
Comp. Hydrated silicate of iron. No
analysis of a British specimen is known
to the author, but foreign specimens con-
tain of silica 39 to 71 per cent. , peroxide
of iron 38 '0, and water 19 '2, the formula
may be written 2Fe26Si + 9H2 (oxygen
ratio = 1 : 2) or Si6O6(Fe2ovi)29OH2.
Loc. Chloropal is abundant in a
quarry at Carn Gray ; near Carclaze
j Mine, St. Austell, of a greenish-brown
colour, with fluor, in fissures of the de-
composed granite; Tremearne, Breage
(Pinguite ?); it is found also in Germany,
Hungary, and Ceylon.
Obs. Careful analyses of this mineral
are much required.
Chlorophane. See Fluor.
CHONDRODITE.
[Humite.] Rhombic ; in very small
complex crystals, like 153 ; sometimes
macled, usually in embedded grains or
granular masses ; fracture sub-conchoidal
or uneven ; transparent to nearly opaque ;
vitreous or resinous ; white, yellow,
brown, red, green, grey, black ; streak
white or slightly yellow or grey : H.
6-6-5 ; G. 31-3-3.
B. , etc. In matrass no change, or turns
first darker and then white ; on C infu-
sible, changes colour sometimes ; with
micro, in the open tube gives the reaction
for fluorine ; with borax or micro, yields
iron reactions ; decomposed by HC1,
yielding a deposit of gelatinous silica.
Comp. Anhydrous silicate of magne-
sia, containing some fluorine. No analy-
sis of a British specimen is known.
Foreign specimens yield from 32 '0 to
36 '0 per cent, of silica, 51 '0 to 60 '0 of mag-
nesia, and 3'0 to 10 '0 of fluorine, which,
perhaps, only replaces a part of the oxy-
gen. With magnesia 64 '0 and silica 36
CHROMITE.
CHRYSOCOLLA. 33
the formula might be 8Mg 3Si (oxygen
ratio = 4 : 3) or with silica 35 3, magne-
sia 60*0, and fluorine 7 '7 the formula
may be Si3Mgo"?(MgFO)j.
LOG. It is said to have been found at
Huel Druid, near Redruth ; it occurs
also in Scotland, Ireland, Germany,
Kussia, Canada, United States, &c.
06s. The crystals are usually very
small, very much modified, and embedded
in granular limestone, or granite, or vol-
canic rocks. It more often occurs in
rounded granular masses or very indis-
tinct prisms. Fig. 153 represents a crys-
tal of chondrodite from New Jersey.
Angles.
MM' = 85° 00' dz = 136°
dd' 112 zz' 127
Chromates. Salts composed of chromic
anhydride, in combination with a metal-
lic oxide ; or chromic acid in which the
hydrogen is displaced by a metal. The
chief mineral chromates are those of iron
and lead (chromite and crocoisite). Of
these only the first has been found in
Cornwall or Devon.
CHROMITE.
[Chrome Iron Ore.] Cubical; in octa-
hedrons (Fig. 1), with imperfect octahe-
dral cleavage ; or massive ; more usually
disseminated in grains ; fracture imper-
fect conchoidal or uneven ; opaque ;
lustre sub-metallic or resinous ; brownish-
black ; streak yellowish to reddish-brown ;
H. 5 '5; G. 4*4-4 '5; sometimes weakly
magnetic.
.B., etc. In matrass unchanged ; on C
infusible, but becomes somewhat brown-
er ; non-magnetic varieties become mag-
netic when heated in R F ; with borax
forms an emerald-green bead ; with
micro, the same ; when fused with nitre
a yellowish mass is formed, which pro-
duces a yellow solution if dissolved in
water ; scarcely affected by acids.
Comp. Chromate and aluminate of
iron. Foreign specimens contain from
36 '0 to 60 '0 per cent, of chromic per-
oxide, 9'0 to 21 '0 per cent, of alumina,
and 18 '0 to 37 0 per cent, of oxide of iron.
The alumina is regarded as replacing a
part of the chromic peroxide. The oxide
of iron is also in some cases partly re-
placed by magnesia. With 32 '0 per cent,
of oxide of iron and 68 '0 of chromic per-
oxide the formula may be written FeCr2
or FeCr2O4 or Cr2O2Feo".
Loc. It was reported from the Lizard
district many years ago, by Mr. Mich ell,
of Calenick. It has been lately re-disco-
vered in a quarry near Cadgwith, by Mr.
Richard Pearce, F.G.S., of Swansea. The
serpentine rock when analysed yielded an
amount of chromic peroxide which was
estimated as equal tol'3 per cent, of the
whole. A portion of the chromite, me-
chanically separated, yielded 30 '0 per
cent, of chromic peroxide. Also in Scot-
land, the Shetland Isles, France, Ger-
many, Norway, United States, &c.
Obs. Chromite is used in the prepara-
tion of a considerable variety of pig-
ments, as chrome-green, chrome-yellow,
&c. It is usually found associated with
serpentine rocks or in crystalline lime-
stones.
CHRYSOCOLLA.
[Silicate of Copper. Siliceous Oxide of
Copper.] Amorphous ; globular, stalac-
titic, reniform ; massive, investing, dis-
beminate, pseudomorphous ; brittle ; frac-
ture conchoidal or splintery; translucent
to neaxly opaque, resinous or wax>y ;
shining to dull ; green or blue, sometimes
brownish or almost white ; streak white
or slightly greenish ; H. 2-3 ; G. 2 '2 to
2-3.
B., etc. In matrass gives off water and
turns black ; on 0 infusible, blackens in
O F, reddens in R F ; with soda yields a
red malleable bead of copper ; with
borax gives Cu reactions ; slowly soluble
in HC1 without effervescence, forming a
green solution and depositing gelatinous
silica.
Comp. Hydrated silicate of copper.
No analysis of a British specimen is pub-
lished, but foreign specimens contain
from 26 '0 to 52 "0 per ceut. of Silica ;
27 '0 to 45*0 per cent, of oxide of copper,
and 16 '0 to 31 "0 per cent, of water,
besides small quantities of alumina, mag-
nesia, lime, potash, and oxide of iron.
With silica 34 '2, oxide of copper 45*3,
and water 20 '5, the formula may be
CuSi2H.2 (oxygen ratio 1 : 2 : 2) or CuSiO3
+ 2H,O or SiOCuo" + 2OH2 or tiiOaCuHo3
+ OHa.
.Loc Huel Edward, St. Just, with
aragonite ; many parts of the Lizard dis-
trict, with native copper ; Ting Tang ;
Huel Gorland; Huel Muttrell; Huel
Unity; West Huel Jewel, and other
mines near St. Day; Prince George Mine,
Gwinear ; Huel Trannack ; Plioauix Mine ;
Grunnislake ; and in most of the copper
mines of the two counties in small quan-
tities; also Cumberland, Westmoreland,
Wales, Scotland, Ireland, Germany,
Hungary, Italy, Siberia, North America,
'"hill, Australia, &c.
Obs. It may be readily distinguished
from malai-hite by the absence of effer-
vescence when treated with dilute HC1 ;
34 CHRYSOPRASE.
CLINOCLASE.
from atacamite by its insolubility in am-
monia ; from the arseniates and phos-
phates of copper by its infusibility.
Pseuclomorphs after cuprite and mica
have been found in Cornwall.
Chrysoprase. See Calcedony.
Chrysotile. A fibrous variety of ser-
pentine much resembling asbestos. (See
Serpentine.)
CHURCHITE.
Oblique? fan -like aggregations of mi-
nute crystals, with one perfect and
several less distinct cleavages ; also ra-
diated and columnar ; brittle ; fracture
conchoidal ; transparent to translucent ;
vitreous, pearly on terminal planes ; pale
smoke-grey tinged with flesh -red ; streak
and powder white; H. 3, or a little
above ; G. about 3 '14.
B., etc. In matrass gives off water
with an acid reaction, and becomes
opaque ; on C becomes reddish in O F,
but is infusible ; with borax in O F gives
a bead which is orange yellow and opa-
line while hot, colourless or slightly
amethystine when cold.
Gomp. It is a hydrated cerous phos-
phate, as appears from the following
analysis, the mean of several, made
by Professor A. H. Church, of Ciren-
cester : —
Phosphoric anhydride 28'48
Oxide of cerium 51 '87
Lime 5'42
Water 14'93
Total IOQ'70
"With 52 '7 of oxide of cerium, 5 '5 of
lime, 27 '8 of phosphoric anhydride, and
14 '0 of water the formula may be writ-
ten 5Ce, Ca, 2P2-f8H2 (oxygen ratio
3 : 5 : 4) or (5-6ths Ce l-6th Ca)3P2 + 4H2
or P4O4Ceo"5Cao" + 8OH2. Professor
Church also obtained a trace of fluorine,
and Mr. C. G. Williams detected didy-
mium by means of the spectroscope.
Loc. It was discovered by Mr. Tailing,
near Lostwithiel, in a copper lode, invest-
ing quartz and killas, forming a coating
of minute crystals about one-tenth of ;an
inch thick. Professor Church has since
detected it in several Cornish apatites
from different localities.
Ob». The cleavage is supposed to be
basal by Mr. N. S. Maskelyne, but clino-
diagonal by Dana. This is the first
British mineral which has been found
to contain cerium. It is well known that
didymium is usually found in minerals
containing cerium, and it is interesting
to find that this is no exception to the
rule, although found in a new locality.
For detailed descriptions of the method
of analysis, &c., see Journal of the Che-
mical Society, and Chemical News, for
1867-8.
Citrine. See Quartz.
Clay. See Kaolin.
Clay Ironstone. See Chalybite.
Cleavage. A property possessed by
many minerals of splitting more readily
in certain definite directions than in
others, and affording shining surfaces,
usually plane, but sometimes curved,
called "cleavage planes;" these cleavage
planes have often a pearly lustre, even
when the general lustre of the mineral is
not pearly. The cleavages are usually
parallel to some of the primary forms.
Cleavelandite. See Albite.
Cleiophane. See Blende.
CLINOCLASE.
[Klinoclase. Clinoclasite. Oblique
Prismatic Arseniate of Copper.] Oblique;
in small crystals, like Figs. 163 to 166 ;
with a perfect cleavage parallel to O,
more commonly in wedge-shaped or
hemispherical aggregates, with curved
cleavage ; and radiated, fibrous, or
columnar structure ; brittle ; translucent
to opaque ; lustre vitreous, pearly, or
resinous ; dark green or dark blue ;
streak bluish-green; H. 2 '5-3; G. 4 '2-
4'4
B., etc. Altogether like Olivenite,
which see.
Gomp. Hydrated arseniate of copper,
as appears from the following analyses : —
a. b.
Arsenic anhydride 29 '71 ... 27 '09
Oxide of copper 60'00 ... 62*80
Phosphoric anhydride ... 0 '64 ... 1'50
Peroxide of iron 0'39 ... 0'49
Lime 0'50 ... —
Silica 112 ... —
Water 7'64 ... 7'57
Totals lOO'OO ... 99-45
The sp. gr. of a. was 4 '258 (4 '359 when
powdered); that of b. was 4 '312. a. was
analysed by Rammelsberg; b. byDamour ;
both were Cornish specimens. With
arsenic anhydride 30 '2, oxide of copper
62 "7, and water 7 "57 the formula may be
written 6CuAs2 + 3H2 (oxygen ratio =
6:5:3) or (CuO)3As2O5-t-3CuH2O2 or
As2O2Cuo"3(CuHo2)3.
Loc. Ting Tang ; Huel Unity ; Huel
Muttrell ; Huel Gorland, and other
mines near St. Day, formerly ; Provi-
dence Mine, Lelant ; and more recently
at Bedford United Mines, near Tavis-
tock, in hemispherical masses of a pure
dark bluish-green colour ; also found in
Germany.
COAL.
COMMON SPAE. 35
Obs. It may be distinguished from
chalcophyllite by its higher specific gra-
vity and darker colour, as also by its de-
flagration on charcoal (chalcophyllite
fuses quietly) ; from torbernite it may be
distinguished by its different blowpipe
reactions and darker colour. The crystals
may always be recognised by their form.
Allan observes, " The crystals usually
present a very dark blue colour and bril-
liant lustre," and " are easily recognisa-
ble, being aggregated in divergent groups,
or disposed in extremely minute indivi-
duals in cavities in quartz."
Angles.
M M' = 56° 00' O r = 123° 48'
M'O 95 00 ra 155 42
Os 80 30 sa 161 00
Oa 99 30 Ma 118 00
Clinodiagonal. The inclined lateral
axis of oblique crystals is so called ; a
cleavage plane parallel to this axis and
the principal is called a clinodiagonal
cleavage. Thus a cleavage parallel to b.
in Fig. 160 will be clinodiagonal ; parallel
to a. would be orthodiagonal.
Coal. This is rather a rock than a
mineral, but a few words here will not
be out of place. The most evident group-
ing of the different varieties of coal is as
follows : —
1. Anthracite.
2. CannelCoal.
3. Caking Coal.
4. Brown Coal or Lignite.
Of these only the first and the last have
occurred in the two western counties,
and these mostly in Devonshire.
The Lignites of Bovey Tiacey have
been worked in connexion with its clays
for many years.
The following is an analysis of the
Bovey Lignite, by Vaux (Journ. Chem.
Soc. 1, 318, 1869):—
Carbon 66'31
Hydrogen 5'63
Oxygen 22 '86
Nitrogen 0'57
Sulphur 236
Ash ., 2-27
Total 100-00
"Thin intermittent beds of Anthra-
cite stretch eastwards from Abbotshnm,
on the shores of Barnstaple Bay, through
Bideford in a straight line to Hawkridge
"Wood, near Umberleigh, a distance of
about twelve miles." (Keport Devon
Assoc., 11, 11, p. 345.) Anthracite has
been worked also at Tavistock. The
author found a shining black carbona-
ceous coating in the joints of the killas
at Huel Jane (near Truro), and near
Hayle. That from Huel Jane when
scraped off and dropped into melted
nitre, deflagrated, Ihus shewing its car-
bonaceous nature.
Cobalt Bloom. Cobalt Coating. Cobalt
Crust. See Erythrite.
COB A LTITE.
[Cobaltine. Cobalt Glance. Bright
White Cobalt.] Cubic; in crystals like
Figs. 1, 2, 8, 32, 43, 45, 46, 48 ; cleavage
perfect, parallel to a, the faces a usually
striated as in pyrites ; more commonly
massive, compact, granular, or dissemi-
minate ; or stalactitic, botryoidal, reni-
form, arborescent ; brittle ; fracture un-
even ; opaque ; lustre metallic ; silvery
or reddish-white, grey or greyish -black ;
streak greyish-black ; H. 5-5 '5 ; G. 6-6 '3.
B., etc. In matrass is unaltered, or
gives a light yellow or white sublimate ;
on C yields copious arsenical and sul-
phureous fumes, deposits a white incrus-
tation, and fuses to a grey brittle mag-
netic globule ; with borax and micro,
yields Co reactions ; decomposed by warm
HNOs, depositing arsenic us anhydride
and sulphur.
Comp. Sulpharsenide of cobalt, often
with nickel and iron. No analysis of a
British specimen is known, but foreign
specimens contain from 19 to 21 per
cent, of sulphur, 43 to 45 arsenic, and 9
to 33 cobalt. With 19 "3 of sulphur; 45 '2
arsenic, and 35 "5 cobalt the formula may
be written CoSAs or CoS2 + CoAs2 or
Co(SAs)2.
LOG. Botallack, in small particles,
embedded in reddish quartz and chlorite ;
it is said to have been found also at the
Wherry Mine, Penzance ; Dolcoath ;
Huel Sparnon ; and St. Austell; also
Sweden, Norway, Germany.
O6s. The crystals are most readily
distinguished from smaltite by their
cleavage.
Angles. Same as pyrites.
00 = 109° 28' a a = 90° 00' &c.
Cockle. See Tourmaline.
Cockscomb Pyrites. See Marcasite.
Cogwheel Ore. See Bournonite.
Colour. A physical character, which
is of considerable importance and very
distinctive in minerals which have a
metallic or submetallic lustre, as Pyrites,
Galena, Wolfram, &c. , but of very little
importance in those whose lustre is
vitreous or resinous, as Cassiterite,
Blende, Quartz, Calcite, &c. Varieties
of these species are, however, often
founded upon colour alone.
Columnar. Made up of small columns.
See Physical Characters of Minerals
(Structure).
Common Felspar. See Orthoclase.
Common Spar. See Quartz.
36
COMPACT.
COPPER.
Compact. A term applied to speci-
mens which exhibit ho peculiarity of
structure. See Physical Characters of
Minerals (Structure).
Concentric lamellar. A structure re-
sembling that of an onion. See Physical [
Characters (Structure).
Concretion. Grown together. Nodules ;
like those of chert and ironstone, the
grains and spherules of oolite, and the
grape-like clusters of the magnesian
limestone are termed "concretions," as
formed by a molecular aggregation, dis-
tinct from crystallization. (Page, Hand-
book of Geological Terms.)
Conchoidal. Shell-like. When a
mineral breaks with a curved fracture, ;
somewhat like the inside of a shell, it is
said to be conchoidal. Ex. Flint.
Condurrite. See Domeykite.
CONNELLITE.
Hexagonal ; in small acicular crystals,
like Figs. 228, 229 ; translucent ; lustre
vitreous; colour fine blue ; streak light
blue (?)
£., etc. In matrass yields a little water
with acid reaction, and decrepitates ; on
C tinges the flame greenish-blue and
fuses to a reddish globule ; with soda
yields a bead of copper ; the slag gives
the reaction for sulphur when moistened
and placed on silver ; soluble in HC1 or
HNO>
Comp. Hydrated sulphatochloride of
copper. No quantitative analysis is
known.
Loc. Huel Providence ; Huel Unity ;
and Huel Damsel, formerly, in slender
prisms, like Figs. 228, 229 ; also fibrous
or massive, in thin veins with other
copper ores.
Obs. The colour of the massive
mineral is much darker than that of the
fibres or crystals. Only a few specimens
are known, and these were all obtained
many years ago. The crystals are about
l-10th of an inch in length, and l-200th
in thickness. Specimens may, perhaps,
be found in old collections ranged with
the arseniates and phosphates of copper.
Anciles.
P P over summit = 73° 40'
PP adjacent 132 50
Pa 143 10
PC 133 53
wV 163 50
ww" 137 10
we 156 02
wa 166 54
Pw 152 37
ac 150 00
cc 120 00
a a 120 00
Observed forma P w a c, PC.
COPPER.
[Native Copper.] Cubic ; in modified
octahedrons, cubes, &c. ; crystals like
Figs. 8 to 16, 59, 60, but usually indis-
tinct ; often macled, or aggregated to
form dendritic, capillary, or interlacing
masses, also in thin laminse or massive ;
malleable ; fracture hackly ; opaque ;
lustre metallic ; copper-red, often with
a brown tarnish, or thin green coating of
malachite ; streak light red and shining ;
H. 2'5 ; G. 8-5-9-0.
B., etc. In matrass unaltered, or
darkens on the surface somewhat ; on C
fusible at 3 to a bead which is bright
while hot, but covered with a dull black
crust of oxide when cold, and generally
tinges the flame slightly green ; when
moistened with HC1 and heated colours
the flame intensely blue ; soluble readily
in HNO3, forming a green solution and
giving off orange coloured fumes.
Comp. Copper, almost pure ; contain-
ing sometimes a little iron, silver, or
bismuth.
Loc. Botallack, Huel Cock, and other
mines at St. Just, in ramose and mossy
aggregations ; many parts of the Lizard
district, in the joints of the serpentine ;
Bellurian Cove and the Ghostcroft, near
Mullion ; Pradannack, in conglomerate
with pyrites ; Binner Downs and Tre-
nance, near Helston; Leseave, Trewa-
vas, New Hendra, and Huel Prosper, in
Breage, (in thin veins); Owen Yean, St.
Hilary ; Providence and other mines near
St. Ives; East Relistian, and other mines
in Gwinear ; Huel Crenver, in Crowan ;
Huel Gorland, Huel Unity, and other
Gwennap mines (Figs. 1, 2, and other
forms, and in thin leaves filling joints in
quartz); Huel Buller, Huel Basset, and
other mines near Cam Brea ; Tresavean,
lately, in arborescent forms with chlorite
and oxide of iron; Condurrow, Dolcoath,
Cook's Kitchen, and the mines near
Camborne ; Cam Brea and Huel Druid,
like Fig. 1, with a dull brown tarnish,
and also in thin plates, dendritic, and
mossy ; Huel Music, Polberrow, and
other mines in St. Agnes ; Great St.
George Mine, Perranzabuloe ; Crinnis
and Great Dowgas, near St. Austell ;
East Crinnis, Par Consols, and Lanescot,
near St. Blazey (reticulate); Gunnislake ;
"West Caradon ; Fowey Consols ; Phoenix ;
Devon and Courtenay, Devon Great Con-
sols, Huel Crebor, and other mines near
Tavistock ; also many other parts of Eng-
land ; Wales, Scotland, Ireland, and
most of the countries in Europe, and
many parts of Asia, Africa, America,
and Australia.
Obs. Copper may be readily recognised
COPPEB BLACK.
CEOMFOEDITE.
37
by its colour when freshly cut, and its
malleability. Figs. 3 and 4 are com-
pressed macles observed in Cornish spe-
cimens.
Angles,
00= 109° 28' a d = 135° 00'
a a 90 00 ae 153 26
dd 120 00 ee' 143 08
ao 125 16 de 161 34
d o 144 44
Copper Black. See Melaconite.
Copper Glance. See Chalcocite.
Copper Green. See Chrysocolla.
Copper Mica, See Chalcophyllite and
Torbernite.
Copper Nickel. See Mccolite.
Copper Pyrites. See Chalcopyrite.
Copper Vitriol. See Cyanosite.
Copper Uranite. See Torbernite.
Copperas. See Melanterite.
Coralloid. Branched like a coral. Ex.
flos-ferri.
Cornish Diamond. See Quartz.
Cornish Tin Ore. See Cassiterite ("Wood
Tin).
CORNWALLITE.
Amorphous ; reniform, or minutely
botryoidal ; compact or disseminate in or
on Olivenite ; brittle ; fracture conchoi-
dal ; lustre non-metallic ; rich verdigris
or dark green ; streak the same ; H.
4'5; G. 41-4'3.
/?., etc. In matrass and on C like
Olivenite.
Comp. Hydrated arseniate of copper,
as appears from the following analyses : —
a. b. c. d.
Arsenic anhy-
dride 2978 30*65 30 '00 29 '00
Phospho ric
anhydride.. 2 '54 177 — —
Oxide of cop-
per . 55-00 54-22 54 '00 51 '00
Water 12 '68 13 '36 16 '00 18 '00
Total ... 100-00 100-00 100 '00 98 '00
All were Cornish specimens, a. and b.
were analysed by Lerch; c. and d. by
Chenevix ; the sp. gr. of d. was 4 '28.
Another analysis by Lerch (e.) is given
below, compared with twc recent analy-
ses by Church, (f. and g.)
e. f. g.
Oxide of copper 54'61 59'95 58'33
Arsenic anhydride... 30 '21 30 '47 3375
Phosphoric an-
hydride 216 271 —
Water ... .. 13'02 8 '25 7 '92
Totals 100-00 101-38 100 '00
In the analyses f. and g. the water la
much less than in the other. If in the
earlier analyses the water were merely
determined by difference, the anomaly
might easily be explained. With arsenic
anhydride 32 '0 per cent., oxide of cop-
per 55-4, and water 12 '6 the formula may
be written As25Cu5H3 or Cu32AsO4+
2CuH2O2 + 3H2O or As2O2Cuo"3 + 2CuHo2
+ 3OH2. This shews it to be closely
related to ehlite. Church adopts the/or-
mula As25Cu3H2.
Loc. Probably some of the Gwennap
Mines.
Obs. It may be readily distinguished
from chrysocolla, which it much resem-
bles, by its hardness and blowpipe reac-
tions ; from malachite, by its solubility
without effervescence in
COVELLITE.
[Covelline. Indigo Copper.] Hexa-
gonal ; with perfect basal cleavage ; crys-
tals very rare ; usually massive, folia-
ceous ; reniform, investing, pulverulent,
or granular ; sectile ; thin leaves flexible ;
opaque ; lustre submetallic, pearly, or
greasy ; deep blue ; streak black, or
dark lead-grey; shining; H. 1*5-2; G.
3 '8 to 3'9 ; crystals 4 '6.
£., etc. In matrass givei a sublimate
of sulphur ; in open tube sulphureous
fumes ; on C burns with a blue flame
and sulphureous odour, and fuses to a glo-
bule of copper, which is more perfectly
reduced by the addition of a little soda ;
decomposed by HNO3, forming a green
solution, and leaving a white deposit of
sulphur.
Comp. Anhydrous sulphide of copper.
No analysis of a British specimen is
known, but foreign »pecimens yield from
32'0 to 34-3 per cent, of sulphur and
64 '5 to 66 "0 of copper, with usually a little
lead or iron. With copper 66 "5 and sul-
phur 33-5 write Cu2S2 or CuS.
Loc. Huel Kind, St. Agnes; Huel
Maudlin, investing chalcopyrite ; Cam
Brea, pulverulent ; also Vesuvius,
Saxony, Poland, Thuringia, &c.
CROMFORDITE.
[Phosgenite. Horn Lead.] Pyramidal ;
usually in four-sided prisms more or less
modified; with three easy cleavages
forming angles of 90° 0' and 135° 0'; brit-
tle or almost sectile ; fracture conchoi-
dal; transparent to translucent; lustre
adamantine to waxy ; white, or greyish,
yellowish, greenish, brownish; streak
whibe; H. 2-5-3; G. 6-6 '3.
£., etc. In matrass melts and some-
times turns darker while hot ; on C
melts at 1 to a yellow globule, which
becomes white and crystalline on
38 CEONSTEDTITE.
CRYSTALLOGRAPHY.
cooling ; in RF gives a bead of lead with
white coating of chloride of lead ; with a
micro, and oxide of copper gives the re-
action for chlorine ; soluble with effer-
vescence in HNO3.
Gomp. Anhydrous chlorocarbonate of
lead. The Cornish specimen has not been
analysed, but three specimens from Derby-
shire yielded the following results : —
a. b. c.
Carbonate of lead ... 48 '4 48 "45 48*22
Chloride of lead 53 '5 50 '93 51 '78
a. by Klaproth, b. by Eammelsberg, c.
by Smith. "With carbonate of lead 49' 0
and chloride of lead 51 '0, or oxide of lead
81 '9, carbonic anhydride 8'1, and chlorine
13 '0 the formula may be written PbC +
PbCl2 orPbCO3 + PbCl2 or COPbo"PbCl2.
Loc. One specimen only has been
found in Cornwall, which is like Fig. 78,
its exact locality is believed to be Huel
Confidence, Newquay, St. Columb Minor.
It occurred in a gozzan. Also Derby-
shire and Scotland, Sardinia and Silesia,
but very rare. Some crystals from Der-
byshire were sold at prices from £15 to
£20 each.
Obs. It may be readily distinguished
from Cerussite by the reaction for chlo-
rine with oxide of copper, and by the
form of the crystals. The cleavages are
parallel to O, M, a.
Angles.
M O = 90° (MX O x = 123° 08'
MM 90 00 Os 112 24
Oa 90 00 xx' 113 48
Ma 135 00 xx 107 21
M u 161 34 s a 145 47
MX 146 54 ss 131 10
Ms 151 26
CRONSTEDTITE.
[Chloromelane.] Hexagonal; in three
or six-sided prisms, vertically striated,
and often in radiating aggregations of
such prisms, tapering somewhat toward
the summit, sometimes in hemihedral
or macled forms, like Figs. 219, 236, 237,
238 ; or reniform ; or massive, fibrous, or
amorphous ; cleavage parallel to O, very
perfect, sometimes curved ; brittle ; thin
fibres, somewhat flexible and elastic ;
translucent to opaque ; lustre vitreous,
brilliant ; black ; streak very dark green ;
H. 2-5-3-5; G. 3 '3 to 3 '5.
B., etc. In matrass gives off water;
on C froths and fumes somewhat on
the edges, yielding in the RF a grey
or black magnetic globule ; with borax
gives the reactions for iron and manga-
nese ; with soda on Pt. foil the reaction for
manganese ; decomposed by strong HC1,
leaving a deposit of gelatinous silica.
Comp. Hydrous silicate of iron. Two
analyses of Cornish specimens, by Pro-
fessor N. S. Maskelyne and Dr. Flight,
yielded the following results : —
a. b.
Iron peroxide 36 '762 32752
Iron protoxide 36 '307 38 '570
Silica , 17-468 18'546
Lime 0'087 —
Water..., , 10 '087 10132
Totals 100711 lOO'OOO
With protoxide of iron 41'54, peroxide
of iron 30 '77, silica 17 '31, and water
10*38 the formula may be written 3FeSi
O4 + 4(Fe2)viH6O6. A small sample very
carefully picked actually yielded 41*272
of iron protoxide.
Loc. Huel Maudlin, Lanlivery, in
divergent groups, like Figs. 219, 236,
237, 238, on chalybite and decomposing
pyrites, with Hisingerite and Vivianite ;
also found in Bohemia and Brazil.
Obs. It is one of the rarest British
minerals, only a few specimens having
been obtained. Some recent observations
on the peculiarities of its form, &c. , will
be found in the Journal of the Chem.
Soc. for Jan., 1871, p. 11.
Crosscourse Spar. See Quartz.
Cryptocrystalline. Amorphous.
Crystal. Minerals which occur in geo-
metrical forms are said to be crystallized.
Each specimen is a " crystal," twin crys-
tal, or group of crystals. The surfaces
are termed "planes," even when curved,
rough, or striated. The meeting of two
planes produces an " edge ;" of three or
more planes an ' ' angle. "
Crystalline. Made up of small and
indistinct crystals.
Crystallography. The science of crys-
tals. The numerous forms of crystals met
with in nature are usually referred to six
simple types or "systems," depending
upon the number, position, and relative
lengths of certain imaginary lines called
" axes," to which the various planes are
referred. Some of the names which
these systems have received from various
writers are here set down, the first men-
tioned being the names adopted in this
work.
1. CUBICAL. Trimetric.
Monometric. Orthotype.
Tessular. Orthorhombic.
Isometric. One & one axial.
Kegular. 4. OBLIQUE.
2. PYRAMIDAL. Monoclinohedric.
Tetragonal. Monoclinic.
Dimetric. Hemiorthotype.
Two & one axial. Two & one inem
3. RHOMBIC, bered.
Prismatic. 5. ANOETHIC.
CUBE.
CUPEITE.
Triclinohedric. 6. HEXAGONAL.
Triclinic. Rhombohedral.
Anorthotype. Three &one axial.
One & one mem-
bered.
1. Cubical. THREE AXES, AT EIGHT
ANGLES, EQUAL IN LENGTH ; primary
form, the octahedron (Fig. 1), or the
cube (Fig. 2).
2. Pyramidal. Three axes, at right
angles, two equal, one longer or shorter.
The unequal axis is called "principal,"
the other two are ' ' lateral. " Primary
form, a double pyramid with square base,
or a prism with square base.
3. Rhombic. THREE AXES, AT RIGHT
ANGLES, ALL UNEQUAL. One is chosen
for the " principal," of the remaining
axes the longer is termed ' ' macrodiago-
nal," the shorter " brachy diagonal. "
Primary form, a double pyramid on
rhombic base, or a prism on a rhombic
base.
4. Oblique. THREE AXES ; TWO IN-
TERSECT EACH OTHER AT AN OBLIQUE
ANGLE, AND ARE CROSSED BY THE THIRD
AT RIGHT ANGLES ; ALL UNEQUAL IN
LENGTH. One of the oblique axes is
chosen for principal ; the one which
forms a right angle with this is termed
" orthodiagonal," the other lateral axis
is " clinodiagonal. " Primary form, an
oblique double pyramid, or oblique
prism.
5. Anorthic. THREE AXES, ALL IN-
CLINED, ALL UNEQUAL. One is chosen
for principal, the others are macro and
brachydiagonal. Primary form, a doubly
oblique double pyramid, or doubly
oblique prism.
6. Hexagonal. FOUR AXES ; THREE
LATERAL, EQUAL IN LENGTH AND LYING
IN ONE PLANE, AND MAKING WITH EACH
OTHER ANGLES OF 60°, THE FOURTH PRIN-
CIPAL, AT RIGHT ANGLES, AND OF ANY
LENGTH. Primary form, a double pyra-
mid on a hexagonal base, or a prism on
the same base.
Cube. A solid six-sided figure, the
sides equal squares. (Fig. 2.)
Cube Ore. See Pharmacosiderite.
Cupellatioi.. A method of separating
the noble metals from lead and other
impurities. It may be successfully per-
formed on a small scale as follows : — A
hole is made in a piece of charcoal, about
one -half of an inch wide and the same in
depth. This is filled with slightly mois-
tened bone ash (a bone burnt in an open
fire and finely crushed will do very well),
and pressed down with some smooth con-
vex surface so as to produce a correspond-
ing smooth concavity. In this hollow
the assay, mixed with several times its
weight of lead (unless the sample be a
lead ore), is placed, and treated with a
strong oxidising flame. The lead will
become oxidised and sink into the bone
ash, carrying any impurities with it, and
leaving the noble metal, gold or silver, as
the case may be, on the surface. If the
operation be well done the bead will be
very nearly a perfect sphere. In this way
silver may be detected in a few grains of
almost any specimen of galena, a mag-
nifying glass being used to detect the
bead of silver.
CUPRITE.'
[Red Copper Ore. Red Oxide of Cop-
per.] Cubical; in cubes, octahedrons,
rhombic dodecahedrons, and other forms
(Figs. 1, 2, 3, 8, 9, 10, 11, 12, 13, 14, 15,
16, 24, 30, &c.); cleavage parallel to O,
perfect ; also fibrous, granular, compact,
earthy, or disseminated ; brittle ; frac-
ture conchoidal or uneven ; subtranslu-
cent to opaque ; submetallic, adaman-
tine, silky ; splendant to dull ; various
shades of red to dark reddish-grey, often
with a dark brown tarnish, or sometimes
a green coating of carbonate ; streak
brownish-red, shining, or earthy ; H.
3*5-4; G. 5-6-6-2.
Var. Chalcotrichite, capillary red
oxide, or plush copper, is a fibrous
variety, with silky lustre and very beau-
tiful red colour, which seems made up of
elongated cubes.
Tile ore is a massive earthy variety,
which often contains a considerable pro-
portion of oxide of iron.
Ruby Copper consists of small and
brilliant crystals of a dark red colour.
B. , etc. In matrass no change, or be-
comes darker ; on C with a strong flame,
RF, is reduced to a bead of Cu ; with
borax and micro, gives Cu reactions ; if
moistened with HC1 tinges the tip of the
flame bright blue ; soluble in HC1,
HNOs, and ammonia.
Gomp. Anhydrous cuprous oxide. The
following analysis of a Cornish specimen
is by Chenevix : —
Copper 85'5
Oxygen 11*5
Total 97-0
With copper 88 78 and oxygen 11 '22 the
formula may be written Cu2 or Cu2O.
Loc. Fine specimens of crystallized
cupr'te have been obtained from Huel
Basset, South Huel Basset, South Huel
Frances, Huel Buller, Huel Druid, and
other mines near Redruth ; Huel Music ;
Dolcoath ; Cam Brea ; Tincroft ; Huel
Unity ; Huel Gorland ; Huel Prosper ;
40
OYANOSITE.
DEMIDOFFITE.
Huel Muttrell; Huel Virgin; Ting
Tang ; Treskerby ; Huel Crenver ; Huel
Abraham ; St. Ives Consols ; Huel Ed-
ward, Huel Speed, Botallack, and other
St. Just mines ; Mullion, and other
places in the Lizard district ; Pplgear,
Wendron ; Fowey Consols ; Gunnislake ;
Phoenix Mines ; Carvath United, Cals-
tock ; Huel Crebor ; Devon Great Con-
sols ; Bedford United ; and other mines
in Devon and Cornwall.
Chalcotrichite has been found at South
Huel Frances ; West Huel Basset ; Huel
Unity ; Huel Gorland j Owen Vean, St.
Hilary ; Gunnislake ; Phoanix ; Fowey
Consols ; Huel Charlotte, St. Agnes
(1825); &c.
Tile Ore occurs in very many of the
above-named mines. Cuprite occurs also
in France, Spain, Germany, Italy, Sibe-
ria, Australia, Cuba, Chili, the United
States, &c. , •
Obs. The figures referred to above are
all Cornish or Devonshire forms.
Angles.
00= 109° 28' n a = 144° 44'
a a 90 00 no 160 32
d d 120 00 p o 164 12
oa 125 16 pd 160 32
da 144 44
CYANOSITE.
[Chalcanthite. Blue Vitriol.] Anor-
thic ; crystals somewhat like Fig. 183,
with an imperfect cleavage parallel to
M ; also amorphous, stalactitic, renif orm,
fibrous, pulverulent ; brittle ; fracture
conchoidal or uneven; semitransparent
to translucent ; lustre vitreous ; various
shades of blue, or greenish-blue ; streak
white; H. 2 '5; G. 2 '2-2 '3; taste very
nauseous and metallic.
£., etc. In matrass melts very readily
at first, gives off large quantities of
water and acid vapours with a strong
smell of sulphur ; finally becomes a
nearly white dry mass ; on C is readily
reduced to a bead of Cu, tinging the
flame green ; soluble in water, forming
a blue solution, which deposits a film
of Cu upon clean iron.
Comp. Hydrated cupric sulphate.
When pure its composition is nearly —
Oxide of copper 32'00
Sulphuric anhydride 32 '00
Water ... .36'00
Total 100-00
This may be represented by the follow-
ing formulae :—CuS + 5H2 or CuSO4 +
5H20 or SOaCuo"50H2.
Loc. Ting Tang, and other mines in
Gwennap, in crystals nearly an inch
long, formerly ; St. Ives Consols ; Tre-
varthen, near Marazion ; Botallack, in
the Crown's lode, at 165 fathoms from
the surface, fibrous and crystallized ;
South Frances, and other mines near
Kedruth ; West Huel Jane ; Gunnislake,
fibrous and massive ; also found in Wales,
Ireland, Hungary, Germany, Sweden,
Spain, Chili, &c.
06s. It is often found on burrows and
in old workings, and is a product of the
decomposition of other copper ores. The
water from most copper mines has usu-
ally some cyanosite in solution. Works
for the extraction of the copper have
been established from time to time at
Carnon, Perranzabuloe, and other places.
For this purpose it is only necessary to
leave pieces of scrap iron in the cupreous
water, when the copper is slowly preci-
pitated upon the iron. Beautiful speci-
mens of precipitated copper are occasion-
ally found on nails and fragments of iron
in the old workings of copper mines.
A ngles.
O M = 108° 12' M n = 153° 44'
OT 127 31 Mv 126 10
MT 123 10 Ov 125 38
Mr 126 57
D.
Dark Eed Silver Ore. See Pyrargyrite.
Decomposed. Separated into its ele-
ments, or into less complex parts.
Decrepitation. The crackling noise
heard when many minerals are suddenly
heated. The mineral usually flies to
pieces. Ex. Blende, Wolfram,
Deltohedron. A regular solid geome-
trical figure, bounded by 24 equal "del-
toids " (Fig. 5). It is a common form for
crystals of garnet, and hence is sometimes
called the granatohedron.
Deltoid. A plane four-sided figure,
such, that one of its diagonals divides it
into two equal scalene, and the other into
two unequal isosceles triangles.
DEMIDOFFITE.
Amorphous ; earthy ; translucent to
opaque; surface splendant; sky blue or
greenish; streak blue; H. 2; G. 2 '25.
B. , etc. In matrass turns darker and
gives off water ; on C alone turns dark ;
with borax yields a grain of copper ; de
composed by acids, depositing silica.
Comp. Hydrated silicate and phos-
phate of copper.
Loc. It is said to be found in Corn-
wall (Bristow's Manual of Mineralogy, p.
107) ; and in Cumberland, in company
with quartzose ro^k and malachite ; also
Valparaiso.
DIALLOGITE.
DOLOMITE.
41
Obs. It covers some of the malachite
of Nischne Tagilsk in delicate layers.
Dendritic. Tree-like, branched. A
term applied to the branching forms com-
mon in native silver and other minerals.
Desmine. See Stilbite.
Devonite. See Wavellite.
Diallage. See Pyroxene.
DIALLOGITE.
[Carbonate of manganese.] Hexago-
nal ; in small rhombohedrons, drusy ag"
gregates, reniform masses, earthy crusts?
or pulverulent ; brittle ; fracture uneven ;
opaque or translucent on thin edges ;
vitreous to pearly ; rose-red or brownish,
often with a dark tarnish ; H. 4-5 ; G.
3'4-3-G.
B. , etc. In matrass turns darker ; on
C alone infusible ; with soda forms a
green bead ; with micro, or borax gives
Mn reactions ; soluble with effervescence
in warm HC1 or HNO3.
Oomp. Anhydrous carbonate of man-
ganese. Church obtained from a Corn-
ish specimen, of a pale rose red colour,
and very pure :—
Oxide of manganese 60*29
Oxide of iron 1*65
Carbonic anhydride 38 '36
Total 100-30
Pure specimens have the following
composition : —
Oxide of manganese 61 "76
Carbonic anhydride 38 '24
"With this composition the formula may
be written MnC or MnCO3 or COMno".
The manganese is often partially replaced
by magnesia or lime.
Loc. Said to have been found at
Bovey Tracey, Botallack, and Huel
Owles ; also found in Shropshire, War-
wickshire, Ireland, Germany, Hungary,
Transylvania, Spain, United States, &c.
Diaphaneity. A general term expres-
sing the degree of transparency or
opacity of minerals. The several degrees
are : —
a. Transparent. Outlines can be dis-
tinctly seen through such sub-
stances.
b. Semitransparent. Outlines may be
seen, but are indistinct.
c. Translucent. Light passes through,
but no outline can be seen.
d. Subtranslucent. Light is only trans-
mitted through thin edges or splin-
ters.
e. Opaque. No light is transmitted.
Dichroic. Minerals which appear to
be of two different colours by transmitted
light, according to the direction in which
they are viewed, are said to be dichroic.
Those which appear of three colours are
said to be trichroic. Tourmaline is often
dichroic, and axinite is trichroic.
Dihedral. Having two planes. A
crystal like Fig. 160 is said to be a prism
with a dihedral summit.
Dimorphism. This term is used to
express the property possessed by some
substances (both simple and compound),
of crystallizing in forms derived from
two distinct sets of crystallographic axes.
Thus carbon as diamond is CUBICAL, but
as graphite it is HEXAGONAL. A sub-
stance which crystallizes in three forms
is trimorphous. Sometimes the term
polymorphous is used when the substance
appears in more than two forms.
The following cases of dimorphism
occur in Cornwall or Devon : —
Sulphide of Iron, f Pyrites : CUBIC.
FeS2. ( Marcasite : EHOMBIC.
Carbonate of ( Calcite : HEXAGONAL.
Lime, CaCO3. ( Aragonite : EHOMBIC.
The following is a case of trimor-
phism :—
Titanic [Entile: PYRAMIDAL.
anhydride, < AnataserPYKAMiDAL.
TiO2. (Brookite: EHOMBIC.
Disseminated. Sown or scattered. A
term applied to minerals, whether crys-
tallized or not, which seem to be scat-
tered in small particles through a mass of
another kind of matter.
Divergent. Crystals which diverge
from a common point of support are said
to be divergent.
Dogtooth Spar. See Calcite.
Dodecahedron. A solid figure, bounded
by 12 planes. The chief dodecahedrons
are the following : —
a. Rhombic Dodecahedron (Fig 3). This
is bounded by 12 equal rhombs.
b. Deltoid Dodecahedron (Fig. 34).
Bounded by twelve equal deltoids.
c. Trigonal Dodecahedron (Fig. 35).
Bounded by twelve equal triangles.
d. Pentagonal Dodecahedron (Fig. 43).
Bounded by twelve pentagons.
DOLOMITE.
[Bitter Spar. Brown Spar. Pearl
Spar.] Hexagonal; in rhombohedrons,
which are often curved ; or in other
forms resembling those of calcite and
chalybite (Figs. 197 and 231); cleavage
perfect, parallel to E, but often curved ;
also massive, granular, or compact;
translucent to opaque; lustre vitreous,
resinous, or pearly, especially on cleav-
ages ; white, yellow, brown, greenish,
reddish, black ; streak white, or slightly
tinged as the colour in coloured varie*
ties; H. 3-5-4; G. 2 -8-31.
42
D01LEYKITE.
ELECTRICITY.
Far. a. Bitter Spar is a variety with
a bitter taste.
b. Brown Spar is the name given to
dark brown varieties.
c. Pearl Spar includes those varieties
which have a pearly lustre.
d. Ankerite is a variety containing a
considerable proportion of carbonate of
iron.
#., etc. In matrass unchanged ; on C
alone infusible, but becomes alkaline ;
wben treated with Co the light-coloured
varieties turn pink or reddish ; the
darker varieties often turn brown or
black from the presence of iron ; slowly
soluble in HC1 or HXO3, with but a
slight effervescence.
Comp. Anhydrous carbonate of lime
and magnesia, with very often some iron
or manganese. The mean composition
of pure specimens is somewhat as
follows :—
Lime 30-34
Magnesia 21 '80
Carbonic anhydride 47 '86
Total 100-00
"With this composition the formula may
be written CaMg2C or CaC03 + MgCO3
or C2O;jCao"Mgo".
LOG. Botallack, Huel Castle, Huel
Owles, Levant, St. Just Amalgamated,
and other St. Just mines, on quartz and
brown iron ore; St. Ives ; New Rose-
warne; Trevascus; North Roskear; West
Chiverton ; Great South Chiverton ; Pen-
hale ; Polgooth ; Garras ; South Hooe ;
Beerferris ; Beeralstone, on flujr; near
Kitley Park, rose-coloured ; also Cum-
berland, Yorkshire, Scotland, Germany,
Italy, Switzerland, Hungary, Tyrol,
Norway, Sweden, the United States, &c.
Obs. It is perhaps only a variety of
calcite, rich in magnesia. It seems to
pass into chalybite by an increasing pro-
portion of iron. It may be distinguished
from calcite by its superior hardness and
density.
Angles. Nearly the same as those of
calcite.
RR' = 73° 55' R'R' = 106° 15'
DOMEYKITE.
(Condurrite. Arsenical Copper Py-
rites.] Amorphous ; massive or disse-
minate ; fracture uneven or flat conchoi-
dal ; lustre metallic or dull ; tin-white,
yellowish, brown, or black ; H. 1-3 "5 ;
G. 4-5.
Far. Condurrite is a variety which is
brownish-black externally, but tin-white
or yellowish on a freshly exposed surface.
It is so soft as to soil the fingers.
B., etc. In matrass yields usually
some water, and a white or yellowish
sublimate ; on C fuses at 1, giving off
arsenical fumes; with soda and borax
yields a bead of copper ; insoluble in
HC1 ; ^partially soluble in HNO>
Comp. Anhydrous arsenide of copper,
the water being only mechanical and in
partially decomposed specimens. The
analyses of Blyth (a) and Faraday (b)
gave as the mean composition of con-
durrite —
a. b.
Arsenic 28'85 ... 29'89
Copper 7115 ... 7011
Totals 100-00 '.'.'. 100-00
With arsenic 28 7 and copper 71 "3, the
formula may be written Cu3As or AsCu3.
Loc. Condurrite has been found from
time to time at Condurrow Mine, Cam-
borne ; and at Huel Druid, Redruth, in
dark coloured, nodular, earthy masses.
Dropstone. A local name for Stalag-
mites.
Drusy. "Dewy." A surface which
appears sprinkled with very small crys-
tals ; or the crystals themselves.
E.
Earthy. A mineral; the surface of
which when broken is somewhat soft,
and presents a multitude of minute
prominences without lustre, is said to be
earthy. An earthy smell is that which
is yielded by clayey substances when
breathed upon.
Earthy Manganese. See Wad.
Effervescence. The peculiar frothy
appearance observed when acids are
poured upon limestone, and all similar
phenomena, are called effervescence. It
arises from the rapid disengagement of a
multitude of minute bubbles of gas.
Efflorescence. The peculiar powdery
appearance produced on crystals of car-
bonate of soda and other substances
when exposed in dry air is so called.
Eisenkiesel. A ferruginous variety of
quartz.
Eisennickelkies. See Pentlandite.
Elastic. A mineral which, after being
bent, flies back to its original position, is
said to be elastic ; mica is elastic ;
talc, which often much resembles it, is
only flexible.
Electricity. One of the physical char-
acters of minerals. Some minerals be-
come electric by friction, some by heat,
and some by percussion. A very simple
electroscope may be made from a bent
glass rod, from which a small fragment
of gilt paper is suspended by a thread
ELEMENTS.
EEINITE.
43
of silk. On approaching a substance, the
electricity of which is excited by the
above or any other methods, the sus-
pended fragment will move towards it.
Many interesting experiments in electri-
city may be made by means of this simple
instrument. The electricity excited by
these simple means is not always of the
same kind. Thus, fluor and apatite
become negatively, wolfram, mispickel,
and cassiterite positively electrified by
friction. The kind of electricity varies,
however, in the same mineral, according
to the smoothness or roughness of the
rubbed surface.
Elements. Substances which have
not as yet been decomposed. About
sixty-three elements are known to che-
mists, but the great majority of mineral
substances are made up of a few only.
The elements most commonly met with
in the mineral kingdom are —
Oxygen, Aluminium,
Hydrogen, Magnesium,
Nitrogen, Iron,
Carbon, Potassium,
Silicon, Sodium,
Calcium, Sulphur.
See Part I. of this work for a complete
"TABLE OF THE ELEMENTS," with their
specific gravities, &c.
Elvan. A Cornish name applied to the
porphyritic dykes which intersect most
of the mining districts. Many of them
are highly felspathic, and some contain
disseminated crystals of felspar, quartz,
schorl, pinite, and other minerals.
Emerald. See Beryl.
Endellionite. See Bournonite.
EPIDOTE.
Oblique ; in modified, often macled
prisms ; one perfect cleavage, parallel to
M (Fig. 159), and oue imperfect, making
angles of 115° 24' ; also columnar, granu-
lar, radiating, or massive ; brittle ; frac-
ture uneven, conchoidal, or splintery ;
semitransparent to translucent on thin
edges ; vitreous ; pearly on cleavage ;
green, yellow, red, brown, black, often
pleochroic; streak white; H. 6'5; G.
3-3-5.
VOLT. The epidotes are divided into
four groups, as follows :—
a. Lime and iron epidote.
b. Lime epidote.
c. Manganesian epidote.
d. Cerium epidote.
The Cornish specimens are probably of
the class a., but no analysis has been
made, the mineral being so scarce.
B. , etc. In matrass no change ; on C
fusible to a glass, especially the dark
varieties ; with borax gives reactions for
Fe or Mn ; with micro, the same, leav-
ing a skeleton of silica in the bead ; in-
soluble in HC1 or HNO3 ; after ignition
partly soluble, depositing powdery or
gelatinous silica.
Comp. Anhydrous silicate of alumina,
iron, and lime. No analysis of a Cornish
specimen is published, but foreign speci-
mens yield about 38 '0 per cent, of silica,
21 '0 of alumina, 16 'Oof peroxide of iron,
and 24 '0 per cent, of lime, with traces
of magnesia. Sometimes the iron is
partly replaced by manganese. With
silica 381, alumina 21 '6, lime 23 '5, per-
oxide of iron 16 '8, the formula may be
written Fe22Al24Ca6Si or 4CaOSiO2+
2Si02-t-2Al203 + Fe203.
Loc. Crowns' Rock, Botallack, in thin
light green radiating groups of crystals,
on dark hornblende rock ; Mr. J. Carne
observes, "Epidote is visible in many
other parts of the same cliff, in veins,
and has also been found in the tin and
copper lodes." (Trans. Roy. Geol. Soc.
of Cornwall, vol. ii.); Carn Silver,
with Pyrites ; Lamorna Cove, at the
junction of the granite and slate ; Mara-
zion, in quartz ; St. Keverne ; South
Tresavean, in green acicular crystals, &c. ;
also Cumberland, Wales, Scotland, Ire-
land, Norway, France, Tyrol, &c.
Obs. The crystals hitherto discovered
in Cornwall have not been at all well
defined in form ; some are not unlike
blades of grass, radiating from a centre,
and pressed flat to the surface of the
rock.
Angles.
M r = 11GQ 17' M z = 104° 16'
Ml 90 33 rn 125 16
Mn 104 49 zz 109 51
The face 1 is often striated.
Equivalent That weight of an ele-
ment which is required to displace one
part of hydrogen from a compound, or
which one part of hydrogen will displace.
ERTNITE.
Crystallization unknown ; mammi-
lated, fibrous, concentric ; brittle ;
opaque or subtranslucent ; lustre resi-
nous or dull; emerald-green to grass-
green ; streak apple-green, or paler than
colour; H. 4 '5-5; G. 4 '4.
B., etc. In matrass decrepitates and
gives off water ; on C fuses, giving off ar-
senical fumes ; with borax yields a bead
of copper ; soluble in HXO3.
Comp- Hydrated arsenia^e of copper.
The following analysis is by Turner :- -
ERUBESCITE.
ERYTHBITE.
Arsenic anhydride 3378
Oxide of copper 59*44
Alumina 1 77
Water 5'01
Total lOO'OO
With arsenic anhydride 34 '7, oxide of
copper 59 9, and water 5*4 the formula
might be written As25Cu2H2 or CuO3
As2O5-t-2CuH2O2 or As2O2Cuo"32CuHo2.
LOG. It has been found in old Cornish
collections by Professor Church.
Obs. It is said by Haidinger to come
from the county of Limerick, in Ireland,
hence the name. It occurs in mammi-
lated and concentric crusts, with a
crystalline fibrous structure, and rough
surfaces, which are probably the termi-
nations of minute crystals.
EEUBESCITF.
[Purple Copper. Bornite. Horseflesh
Ore. Buntkupferz.] Cubical; usually
in cubes modified at the angles (Fig. 9),
or macled (Fig. 58); the faces are some-
times curved ; also massive ; sectile or
brittle ; fracture imperfect conchoidal
or uneven ; opaque ; lustre metallic ;
copper-red to bluish or brownish ; often
an iridescent tarnish ; streak greyish-
black, shining ; scratch brownish or pur-
plish ; H. 3-3; G. 4-4-4-5.
.5., etc. In matrass gives a yellow
sublimate ; on C melts to a black or dark
reddish-brown, magnetic, brittle glo-
bule ; when roasted and treated with
a little borax yields a bead of copper ;
if moistened with HC1 colours the flame
blue ; soluble in HC1 or HNO3, forming
a green solution.
Comp. Anhydrous sulphide of copper
and iron. The following are analyses of
Cornish specimens, a., a specimen from
Condurrow Mine, by Plattner ; b., from
a mine near Redruth, by Chodnew ;
both crystallized : —
a. b.
Copper 56-76 ... 57'89
Iron 14-84 ... 14'94
Sulphur 28-24 ... 26'84
Totals 99-84 ... 99'67
With copper 62 "5, iron 13 '8, and sulphur
23 '7 the composition would be expressed
by the formula FeCu.2S3 or 2CuS, FeS.
The iron, however, seems to replace the
copper in different proportions.
Loc. Pennance Consols, in crystals
like Fig. 58; South Tolgus, Huel Buller,
and other mines near Redruth ; Carn
Brea, Dolcoath, Tincroft, Cook's Kit-
chen, Condurrow, Camborne Vean, and
other mines near Camborne ; Tresavean ;
Huel Jewell; Huel Falmouth; Botal-
lack, Levant, and other St. Just mines ;
Huel Alfred; Huel Boys; Great St.
George ; Britannia and Prince Regent,
&c. ; also Somerset, Ireland, Norway,
Siberia, Silesia, Bannat, Hesse, Hun-
gary, &c.
Obs. It may be readily distinguished
from grey copper (chalcocite) by its supe-
rior hardness and by the form of the
crystals; from chalcopvrite by the colour
of the scratch, which is always yellow in
chalcopyrite, but always brownish-pur-
ple in erubescite.
Angles.
a a =» 90° 00' 00 = 109° 28'
ao 125 16
ERYTHRITE.
[Erythrine. Cobalt Bloom. Arseniate
of Cobalt.] Oblique ; in acicular prisms,
like Figs. 170, 171 ; with a perfect cleav-
age parallel to M ; more usually in aci-
cular crystals or radiating groups ; or
earthy crusts ; sectile ; thin plates flex-
ible ; translucent to opaque ; pearly,
vitreous, or dull ; colour crimson, or
other shades of red, usually tinged with
blue, often peach-blossom red, occasion-
ally greenish or greyish ; streak like the
colour, but paler ; sometimes the same
crystal will be both green and red ; H.
1-5-2-5; G. 2-9-3.
B., etc. In matrass gives off water
and deposits a white crystalline subli-
mate ; on C melts to a grey brittle glo-
bule, depositing a white incrustation at
some distance from the assay, and giving
off a powerful odour resembling garlic ;
with borax and micro, a dark blue bead
is formed ; soluble in HC1 and HNO3,
forming a pink solution ; turns black if
treated with KHO.
Comp. Hydrous arseniate of cobalt ;
the cobalt often partially replaced by
nickel. No analysis of a Cornish speci-
men is known, but foreign specimens
yield from 38 "0 to 54*0 per cent, of arse-
nic anhydride, 18'0 to 36 '0 per cent, of
oxide of cobalt, and 12'Oto 24 '0 per cent,
of water. With arsenic anhydride 38 '43,
oxide of cobalt 37 '55, water 24 '02, the
formula may be written As23Co8H2 or
(Co)3As2O5 + SH2O or As2O2Co3" + 8OH2.
Loc. Botallack, near Crown's Engine,
with cobaltite and smaltite ; Roscom-
mon cliff, with axinite ; Huel Tre-
noweth ; Huel Unity ; Dolcoath ; Huel
Sparnon and East Pool, on smaltite ;
Pednandrea ; Polgooth ; Trugoe ; Wills-
worthy Mine, Tavistock; also Cumber-
land, Germany, Hungary, &c.
Obs. The earthy peach-blossom varie-
ties are often found on ores of cobalt
which have been left in damp situations.
ERYTHEITE.
FELSPAR.
45
Angles.
OT = 124° 51' Ts = 137° 06'
MT 90 00 On 149 12
Tk 155 05 OM 90 00
Erythrite. An old name for a peculiar
red variety of felspar.
F.
FA HLERZ.
[Tetrahedrite. Grey Copper. Falilore.]
Cubical ; usually in tetrahedrons, more
or less modified, like Figs. 33, 35, 38, 39,
40, 41, 42 ; also massive or disseminated ;
brittle ; fracture conchoidal, uneven, or
even ; opaque, or very slightly translu-
cent on thin edges; metallic or sub-
metallic ; steel grey to iron black ; crys-
tals often rough and beautifully irides-
cent ; streak brownish, reddish, or
black; H. 3-4; G. 4 '5-5 '2.
Var. Polytelite, or Freibergite, is a
variety containing a notable proportion
of silver. Tennantite is, perhaps, an
arsenical Fahlerz.
#., etc. In matrass gives a red or red-
dish-yellow sublimate ; on C fuses readily
and boils slightly; gives off arsenical
vapours and forms a white incrustation
on the cool part of the charcoal, and
leaves a difficultly fusible magnetic slag ;
with soda and borax yields with difficulty
a bead of copper ; decomposed by HC1 or
HNO3, forming a green solution and a
jight coloured deposit.
Comp. Sulpharsenide or sulphanti-
monide of copper, with variable quanti-
ties of silver, iron, zinc, and mercury ;
the pale varieties contain a large propor-
tion of arsenic usually; the darker
varieties more antimony. Of the two
following analyses of Cornish specimens
a. was by Hemming, from Gwennap, b.
by Michell, from Crinnis : —
a. b.
Copper 48-40 ... 46'00
Arsenic ll'SO ... —
Antimony — ... 21 '00
Iron 14-20 ... 17'20
Sulphur 21-80 ... 14 '00
Silica 5-00 ...
Silver — ... 1'80
Total 100-90 '.'.'. 100-00
The composition is so variable that it is
difficult to give formulae, but with copper
50 "2 per cent., iron 17 '7, arsenic 11 '8,
sulphur 20 '2, the composition might be
written As 2Fe 5Cu 4S, or Cu5 Fe2 S4 As ;
with copper 46 '7, iron 16 '4, antimo D y 18 "0,
sulphur 18 '9 it might be written Cu5Fe2
Loc. Crinnis, and other mines near
St. Austell, in large iridescent crystals
(Figs. 33, 35, 38, 39, 40, 41); Botallack ;
Levant ; Cook's Kitchen, Tincroft, Con-
durrow, Tresavean, Carharrack, South
Huel Basset, and other mines in the
neighbourhood of Camborne and Red-
ruth, formerly ; Trevaunance, St.
Agnes; Huel Prosper ; Herodsfoot ; Tre-
vascus, Trenance; Old Treburgett, St.
Teath (Polytelite), Britannia and Prince
Regent, North Molton ; Beeralstone ;
Combemartin; Tavistock, &c. ; also Scot-
land, France, Spain, Italy, Germany,
Hungary, Mexico, &c.
Obs. The largest crystals have mostly
occurred at Crinnis and other mines near
St. Austell. Fahlerz may be distin-
guished from magnetite and hematite by
inferior hardness ; from mispickel by its
darker colour ; from chalcocite (copper
glance) by supei'ior hardness and brittle-
ness. The crystals may be distinguished
from all other similar minerals except
Tennantite by their form. Tennantite is
probably only an arsenical variety of
fahlerz. Perhaps analysis a. is Tennan-
tite. The Polytelite from Old Treburgett
contains a considerable proportion of
silver.
Angles.
o o = 70° 32' o a = 125° 16'
a a 90 00 od 144 44
on 160 32 dd 120 00
False Topaz. See Quartz.
Felspar. This term, which is com-
monly applied to a particular species
(Orthoclase), is more properly a name
for a group of nearly-related species, dif-
fering from each other, however, in che-
mical composition, crystalline form, and
other characters. Dana says, "The
felspar group is remarkable for its unity
in crystallographic and all physical char-
acters." The felspars are characterized
by a sp. gr. below 2 '85 ; H. 6-7, or
mostly scratched by a good knife ; fusi-
bility 3-5 ; crystallization oblique or
doubly oblique, with two easy and nearly
perfect cleavages forming angles of 90°,
or nearly 90°. In all, the cleavage planes
have pearly lustre, and some varieties of
several species exhibit an opalescence,
or a play of colours, when viewed in cer-
tain directions. They have been sup-
posed to pass into each other by imper-
ceptible degrees, and their chemical com-
position would seem to favour this view,
while the differences of crystalline form
are not great enough to forbid the sup-
position. Dana, however, considers the
microscopic investigation of the felspars
to be entirely in favour of the distinct-
ness of the species. He remarks that
oligoclase and orthoclase are often found
46
FELSPAR.
FLUOR.
together in granite, obsidian, and tra-
chyte, and yet keep themselves distinct,
even to microscopic perfection. This has
silso been shown, by the Rev. Professor
Hiughton, to be the case with albite and
orthoclase in the granites of Cornwall
and of Ireland.
The chief species, according to Dana,
are : —
O. ratio
Cleavages. for RR2Si.
Anorthite ... 94° 10' & 85° 50' 1.3.4
Labradorite. 93 20 86 40 1.3.6
Hyalophane — — 1.3.8
Andesite ... — — 1.3.8
Oligoclase... 93 50 86 10 1.3.9
Albite 93 36 86 24 1.3.12
Orthoclase.. 90 00 90 00 1.3. 12
The amount of silica increases with the
increasing proportion of alkalies, from
anorthite, which is usually without any
alkali, to albite and orthoclase, with the
protoxide bases solely alkaline.
The following table, from Page's Hand-
book of Geological Terms, exhibits the
range of composition of the chief
felspars : —
Sil. Alum. Pot. Soda. Lime. Iron
Ortho. 61-70 15-20 7-14 1-4 1-3 1-2
Albite. 67-71 14-20 1- 4 7-11 1- 3 0-1
Labrad. 43-55 26-30 0-1 1-4 9-12 1-3
Anorth. 42-46 32-37 0-1 0-1 10-18 0-1
Oligo. 60-64 18-24 1- 3 2-10 2- 5 0-1
Only albite and orthoclase have, as yet,
been found in Cornwall and Devon ;
these are described under their respec-
tive headings.
Some of the foreign felspars are valu-
able as ornamental stones, while the
large deposits of kaolin or china clay, in
Cornwall, Devonshire, and elsewhere,
are the results of the decomposition of
felspar, of granite, or perhaps other fel-
spathic rocks.
Felspathic. Containing felspar.
Fibrous. A term applied to some
minerals which occur in, or readily split
into, fine thread-like portions, especially
if somewhat elastic. Ex. Amianthus,
Chalcotrichite, &c. Filamentary and
Capillary are terms used with nearly the
same meaning.
Fibrous Brown Iron Ore. See Limo-
nite.
Fibrous Gypsum. See Gypsum (Satin
Spar).
Fibrous Red Copper Ore. See Cuprite
(Chalcotrichite).
Fibrous Tin Ore. See Cassiterite
(Wood Tin).
Figure Stone. See Agalmatolite.
Filamentary. See Fibrous.
Flaming. A method of testing some
substances with borax or micro, in a
bead before the blowpipe by rapidly
blowing a strong and a weak blast alter-
nately. This intermittent flame, with
some metallic oxides, produces an opaque
bead, when the ordinary treatment
would give a transparent bead. J±x.
Oxide of Zinc.
Flexible. Capable of being readily
bent.
Flint See Quartz (Calcedony). Flints,
apparently derived from chalk rock, are
not uncommon in several parts of Corn-
wall, as Ludgvan, Breage, and other
places near the const, as well as all
around the coast itself on the beach.
They occur also on the high ground of
the Land's End, and some parts of the
Scilly Islands.
Floatstnne. A peculiar vesicular va-
riety of quartz found in some of the
Cornish mines, and elsewhere.
Fluate of Lime. See Fluor.
FLUELLITE.
Rhombic ; in very small pyramids,
with their solid angles truncated, like
Fig. 89, but without the planes v. ; trans-
parent to translucent ; lustre vitreous ;
white; H. 3'0.
Comp. According to Wollaston, it
contains fluorine and aluminium, but an
analysis is much needed.
Loc, Stenna Gwynn, St. Austell,
with Autunite and Tavistockite, on a grey
quartz rock. Sometimes incrusting small
"vugs."
Obs. It was discovered by Levy nearly
60 years ago, but has since been re-dis-
covered by Mr. R. Tailing, of Lostwi-
thiel. Most of the specimens yet dis-
covered are in the British Museum, and
it is intended soon to make a new analysis.
The largest crystals are less than one-
tenth of an inch long.
Angles.
e 0 = 108' 00' e e' = 144° 00'
ee 109 04
FLUOR.
[Fluor Spar. Cann. Blue John.]
Cubical ; in cubes, octahedrons, and
most of the forms from Fig. 1 to Fig.
32, also Figs. 53, 55, 58 ; with perfect
octahedral cleavage ; also compact, nodu-
lar,* granular, fibrous, or earthy ; brit-
tle ; fracture conchoidal or uneven, but
difficult to obtain in crystallized speci-
mens ; transparent to opaque ; vitreous,
splendant to glimmering ; colourless,
white, blue, green, yellow, brown, purple,
red, black; sometimes dichroic; or co-
loured in layers, parallel to the faces of
the simple crystal; exhibits fluorescence
FLUOR.
FLUORINE.
47
in a marked degree ; streak white or
slightly tinted as the colour ; H. 4 ; G.
3-3 '2 ; pyro or f rictio-phosphoric.
Var. Chlorophane is a compact, white,
yellowish, or bluish variety, which is
highly pyro-phosphoric, shining with '
a beautiful green light when mode-
rately heated, especially if newly
raised.
Z?., etc. In matrass often decrepitates,
sometimes changes colour, or phos-
phoresces ; on C decrepitates, melts to an
opaque white crystalline mass, colouring
the flame dull red ; with gypsum melts
to a transparent bead which is opaque on
cooling; slowly soluble in HC1 or HNO3,
giving off a g?.s (HF) which corrodes
glass ; readily decomposed by warm
H2SO4, giving off HF abundantly, and
being converted into sulphate of
lime.
Comp. Anhydrous fluoride of cal-
cium. No analysis of a British speci-
men is known to the writer, but the
usual composition is about 47 per cent,
of fluorine and 53 per cent, of calcium,
which would be represented by the for-
mula CaF.2.
LOG. Huel Spearn, Balleswidden,
Spearn Moor, and other St. Just mines,
but very scarce ; St. Michael's Mount ;
Tremearne, in granite veins ; and Great
Huel Vor, Breage, but very scarce ;
Stray Park, Dolcoath, North Roskear,
and other Camborne mines; East Huel
Crofty, Carn Brea, East Pool (crystal-
lized and amorphous " chlorophane," as-
sociated with wolfram), and other mines
in Illogan ; South Huel Buller, Cardrew
Downs, Pednandrea (crystallized, in many
colours, and amorphous "chlorophane"),
North Huel Grambler (Figs. 1, 7, 9, 21,
23), Huel Sparnon, Huel Damsel, Huel
Gorland, Huel Unity, Huel Unity Wood,
and other mines in Redruth and Gwen-
nap, in great variety of colour and form,
also fibrous, concentric, or earthy ; North
Downs ; Trevaunance, Huel Devonshire,
and other St. Agnes mines, formerly in
beautiful octahedrons made up of minute
cubes, or in cubes with their edges modi-
fied by one, two, or three planes, and
other forms, like Figs. 1, 7, 21, 22, 23,
&c. ; Huel Mary Ann (fine blue modified
cubes, like Figs. 10, 21, 23, &c.), Huel
Trehane, and Huel Trelawny (deep blue
bevelled cubes, like Figs. 18, 21, 22, 23,
&c.), Menheniot; Huel Maudlin, near
Lostwithiel, in large semi-transparent
octahedrons, with chlorite and calcedony ;
South Caradon and West Caradon, St.
Cleer, in colourless elongated cubes, and
like Figs. 1 and 2 ; Stenoa Gwynn ; Holm-
bush ; Huel Franco, Buckland Mona-
chorum ; Virtuous Lady, and other mines
near Tavistock ; East Tatnar Mine ; Beer-
alstone (Figs. 1, 2, 8, 9, 16, 20, 21, 22, 23,
53, 55, &c.) ''The finest crystals are either
colourless, or of a pale sea-green intern-
ally, and upon the surface, or only the
edges, of a rich smalt-blue, or a contrary
disposition of the same col ours " (Greg and
Lettsom, p. 24); also pale-green, translu-
cent, or white and opaque octahedrons on
hornstone ; also fibrous and compact,
Fig. 53 shews part of a magnificent crys-
tal from this locality which was in the
collection of Professor Phillips. It is
probably the most complete crystal of
any mineral yet discovered. The foreign
localities of fluor are almost every-
where where tin, copper, or lead is
mined.
Obs. Fluor occurs massive in most of
the copper mines and many of the tin
and lead mines of the county, but is
somewhat scarce in the extreme west. It
occurs also in pseudomorphs at several
localities (see Pseudomorphs). It is used
as a flux in reducing iron and copper ores,
hence its name from "fluo" to flow.
" Cann," or " Kann," is a Cornish name ;
Blue John a Derbyshire name. Chloro-
phane has, as yet, been found
only at East Pool and Pednandrea
mines.
Angles.
o or - 109° 28' w a = 155 42
a a 90 00 wo 145 46
oa 125 16 xx' 166 57
dd 120 00 xx" 140 09
da 135 00 xa 152 04
fa 161 34 tt" 144 03
ff 126 52 tt' 162 15
mm 120 31 ta 150 48
ma 154 46 ag 147 00
ww' 167 47 ai 174 40
ww" 136 47 yy 177 00
Fluorescence. " This name has been
given to the peculiar phenomenon exhi-
bited by fluor spar, of transmitting one
colour and reflecting another from a thin
layer adjacent to the surface by which
the light enters." (Bristow's Gloss, of
Min., p. xvi.)
Fluorine. This element, occurs in only
a very few minerals, of which fluor is the
chief. It may be readily detected in the fol-
lowing manner :— Heat a small portion of
the assay, in fine powder, in a clean and
dry matrass, and insert in the open end
a small slip of Brazil-wood paper. If any
fluorine be present the tube will be
roughened and rendered opaque inside,
and the paper will turn straw yellow.
Other delicate tests are described in
works devoted to blowpipe analysis.
48
FLUX.
FEANGIBILITY.
Flux. A substance added to a mineral
to increase its fusibility, and sometimes
to carry off one or more ingredients. The
principal fluxes used in determinative
mineralogy are carbonate of soda (soda),
borax, microcosmic salt (micro.), fluor
spar, cyanide of potassium, and boric
acid.
Foliated. A term applied to minerals
which may be split into thin leaves. Ex.
Mica.
Foliated Arseniate of Copper. See
Chalcophyllite.
Form. Minerals which occur in defi-
nite geometrical forms are said to be
crystallized (see Crystallography). Those
which are evidently made up of minute
or imperfect crystals, the form of which
cannot be made out, are said to be crys-
talline. A considerable number of
minerals are not known in the crystal-
lized or crystalline state : these are said
to be amorphous. Many amorphous
minerals, as well as some that are known
as crystals, occur sometimes in imitative
forms. The chief of these are : —
a. Globular. When the shape is sphe-
rical, or nearly so, as in some
varieties of aragonite. When the
spheres are small we have the
pisolitic form ; when very small,
the oolitic.
b. Botryoidal. When the shape is
nearly like that of a bunch of
grapes. Ex. Malachite.
c. Mammillary. In rounded promi-
nences, less separated from each
other than in b. Ex. Blistered
Copper.
d. Reniform. A form somewhat like
that of a bullock's kidney. Ex.
Some forms of iron pyrites. Nodu-
lar is nearly the same.
e. Stalactitic. Icicle shaped. Ex. Sta-
lactite.
f. Goralloidal. In form somewhat
like masses of coral. Ex Some
forms of aragonite (flos-ferri).
g. Acicular. Needle-shaped. This is
more often seen in distinctly crys-
tallized specimens. Ex. Antimo-
nite.
h. Wiry. Ex. Native Silver.
i. Dendritic. Mossy. Ex. Native
Copper,
j. Leafy. In thin plates. Ex. Native
Copper.
Formula. An abbreviated expression
of the chemical constitution of bodies, in
which the different elements present are
represented by their symbols. An em-
pirical formula states only the number
of atoms of each element present. A
" constitutional" or "rational" formula
attempts to express something of the
arrangement of those elements. Thus
As2Co3Hl6O16 is an empirical formula for
Erythrite (Erythrine), while As,3CoSH2
or (CO)3As.jpg + 8H2O or As26sCo"3 +
! 8OH2 are rational or constitutional for-
mulae for the same mineral.
Fracture. A term used for indicating
the kind of surface obtained by breaking
minerals. The chief varieties of fracture
are : —
a. Conchoidal. Shell-like, with the
broken surface shewing curved
concavities somewhat like those on
the inside of a cockle shell. Ex.
Flint.
b. Splintery. Ex. Serpentine.
c. Hackly. The broken surface shew-
ing a number of wire-like points.
Ex. Native Copper.
d. Uneven. Ex. Pyrites.
e. Even. The specimen breaks with
an even surface. It is distinguished
from Cleavage by the fracture
occurring indifferently in any
direction, while cleavages are in
certain defiuite directions.
f. Earthy. This character may occur
in combination with others. It is
used when the broken surface is
seen to be covered with minute
irregularities without lustre. Ex.
Chalk.
Either of these terms may be qualified
by the prefix sub. Thus, sub-conchoidal
indicates an imperfect conchoidal frac-
ture. Fracture must not be confounded
with Cleavage, as many minerals exhibit
both. In some minerals the cleavage is
very perfect and easily obtained, while
the fracture is scarcely to be at all ob-
served. Ex. Mica, Blende, Galena,
Calcifce, £c.
Francolite. See Apatite.
Frangibility. A convenient term for
including such characters as--
a. Brittle. When parts of the mineral
separate in powder on attempting
to cut it. Ex. Calcifce.
b. Sectile. When thin pieces may be
cut off with a knife, but the
mineral pulverizes under the ham-
mer. Ex. Chalcocite.
c. Malleable. When slices may be cut
off, and these slices may be flat-
tened under the hammer. Ex.
Native Copper.
d. Flexible. When the mineral will
bend, and remain bent after the
bending force is removed. Ex.
Native Copper.
e. Elastic When the mineral, after
being bent, will spring back to its
original position. Ex. Mica.
FREIBEKGITE.
GALENA.
49
f. Friable. Crumbling ; easily crushed
between the fingers. Pulverulent
has nearly the same meaning. MX.
Melaconite.
The term Tenacity is sometimes used
in the sense of Frangibility.
Freibergite. See Fahlerz (Polytelite).
French Chalk. See Steatite.
Frictio-electric. Minerals which be-
come electric, by rubbing are said to be
"frictio-electric." Some are "positively"
and some "negatively" electrified by
friction. Ex. Tourmaline.
Frictio-phosphoric. Minerals which
shine with a peculiar light some what like
phosphorus when rubbed are said to be
" f rictio-phosphoiic. " Ex. Some varie-
ties of Quartz.
Fuller's Earth. This is said, by Garby,
to have occurred in Cornwall, but no
locality is given.
Fusible. Capable of being melted.
Minerals which cannot be melted before
the blowpipe are said to be "infusible."
Fusibility, Scale of. The following is
Plattnerr's scale, which is adopted in this
work :—
1. Readily fusible to a bead.
2. With difficulty fusible to a bead.
3. Readily fusible on thin edges.
4. With difficulty fusible on the edges.
5. Infusible.
The following is Von Kobell's scale,
which is more definite, but not so easily
obtained : —
1. Autirnonite.
2. Natrolite.
3. Almandine or precious Garnet.
4. Actinolite.
5. Adularia.
6. Bronzite.
G.
GALENA.
[Lead Glance. Galenite. Sulphuret
of Lead.] Cubical ; in cubes, commonly
modified by planes of the octahedron and
rhombic dodecahedron (Figs. 1, 9, 10, 11,
12, 13, 14, 15, 16, 18, 24, 29, 57, 58, and
other forms), \\ith perfect cleavage par-
allel to a.; also massive, concentric,
botryoidal, incrusting, disseminated ;
drusy, granular, or compact ; brittle or
sub-sectile ; fracture uneven, but not
easily obtained in crystallized speci-
mens ; opaque ; lustre metallic, often
splendant ; lead grey to black ; some-
times with an iridescent tarnish : streak
black; H. 2'5; G. 7 '2-7 7.
Var. Specular galena is a very bii.ht
curved lamellar variety. Blue lead is a
pseudomorphous variety, af er Pyromor-
phite, which occurred at Huel Hope in
1822 and 1825, in hexagonal crystals ; it
will burn in the flame of a candle when
newly raised. Argentiferous Galena, or
Silver Lead, is a name applied to varie-
ties containing a notable quantity of
silver.
ft., etc. In matrass usually decrepi-
tates, and yields a light coloured subli-
mate with a strong heat ; in the open
tube a white sublimate of sulphate of
lead, and sulphureous odour ; on C some-
times decrepitates, melts readily, and is
easily reduced in RF to a malleable bead
of lead, giving off SOg, and depositing a
yellow incrustation on the charcoal. A
minute grain of silver is often yielded by
cupellation ; decomposed by HC1, if in
fine powder ; more easily by HNO3.
Comp. Anhydrous sulphide of lead,
usually with some iron, and sometimes
small quantities of antimony, zinc, cop-
per, silver, &c. With lead 86 '55 per
cent, and sulphur 13 '45 the formula may
be written Pb's or PbSO^ or SO2Pbo".
LOG. West Huel Darlington, Ludg-
van, associated with silver ore and native
silver ; Huel Alfred (with the finest
crystals of Pyromorphite ever found in
Cornwall), and Boiling Well, Phillack ;
Binner Downs ; Huel Pool, Huel Rose,
Huel Penrose, Sithney, with phosphate
and arseniate of lead ; West Godolphin,
Breage ; St. Michael's Mount, in small
spots ; Huel Unity, Gwennap, with very
fine crystals of ai seniate of lead ; Pol-
dice, Tresavean ; Trevascus ; Huel Bas-
set ; Dolcoath; North Roskear ; Huel
Crofty ; Great Huel Baddern, East Huel
Falmouth, Huel Jane, and other mines
in Kea and Kenwyn ; Garras and South
Garras, St. Allen; Budock Vean, Swan-
pool, and other mines near Falmouth ;
Huel Rose, East Huel Rose, Cargoll,
South Cargoll, Newlyu ; Huel Golden,
Huel Penhale, Trebisker Green (with
native silver and silver ore), and other
mines in Cubert ; West Chiverton ; Great
South Chiverton ; North Chiverton ;
Perran Huel Virgin ; Huel Mexico ;
Huel Kayle ; Carclaze Tin Mine, in small
specks ; Pentire Glaze (with very fine
carbonate of lead), Endellion; Trebur-
gett, St. Teath; Huel Ludcott (with
silver ore and native silver), and Huel
Wrey, St. Ive ; Herodsfoot, St. Pinnock ;
Huel Mary Ann, Huel Trehaue, Huel
Trelawny, and other mines in Menhe-
niot ; Redmoor ; Holmbush ; Huel Lang-
ford and Huel Brothers, Calstock.
Huel Lee ; Huel Tamar ; East Huel Ta-
mar ; North Huel Tamar ; Landkey ; Beer-
alstone ; Hennock ; Combemartin ; Berry
Narbor ; Devon and Courtenay ; Huel
50
GALMEI
GAENET.
Betsy; Huel Friendship; Bridford; Oke-
hampton Consols, Holestock, and many
other localities in Cornwall and Devon.
Most metalliferous mines in Cornwall
and Devon have yielded small specks of
lead, but in the majority of the cases
above referred to considerable quantities
of lead ore have been raised.
Argentiferous galena has occurred at
the following mines, as well as others : —
Oz. of silver to the ton of ore.
Beeralstone 80 to 120
South Hoo, a part
of the same mine 140
Huel Betsy, Tavis-
tock (about) 12
Huel Pool, Helston 60 about 1822
Garras Mine, near
Truro 70 „
Huel Kose,Newlyn 60 to 65 „
Swanpool, near
Falmouth Very variable.
Obs. Galena occurs in almost every
mining district where tin or copper is
raised, but is, perhaps, most abundant in
connection with limestone rocks.
The lead ores raised in the two counties
during the year 1869- mostly galena-
amounted to 10,104 tons, which yielded
343,151 ounces of silver, or an average of
nearly 34 ounces per ton. This is by far
the richest raised in the United King-
dom, except that of the Isle of Man,
where the average is more than 40
ounces per ton. (See Min. Stat. for
Great Britain, 1869, by Kobert Hunt,
F.R.S.)
Galena occurs in veins and feeds or
irregular deposits, associated with py-
rites, blende, limonite, chalcopyrite, ca-
lamine, quartz, barytes, and calcite, and
ores of gold, silver, arsenic, &c.
It may be distinguished from argen-
tite by its perfect cleavage and brittle-
ness ; from graphite and molybdenite by
its fusibility ; from dark varieties of
blende by its dark streak and inferior
hardness.
Angles.
00 = 109° 28' n n = 120° 31'
a a 90 00 na 144 44
dd 120 00 no 160 32
oa 125 16 mo 150 30
o d 144 44 ma 154 46
a d 135 00
Galmei. See Calamine.
Gangue. The rocky material in which
a mineral is embedded is called the
gangue, or veinstone. Thus, the ordi-
nary gangue of cassiterite is "capel," a
hard compound of quartz, chlorite, and
oxide of iron.
GARNET.
[Almandine. Colophooite. Melanite ;
&c.] Cubical; usually in rhombic dode-
cahedrons (Fig. 3), or in deltohedrons
(Fig. 5), but often variously modified, as
in Figs. 25, 26, 31, &c. ; one of the axes
is often lengthened or shortened so as to
distort the form ; sometimes macled ;
the faces sometimes curved ; also mas-
sive, compact, granular, lamellar ; very
rarely a distinct dodecahedral cleavage ;
usually tough, but massive varieties some-
times friable ; fracture conchoidal or un-
even ; transparent to opaque ; vitreous
or resinous ; sometimes white, but more
usually various shades of red, yellow,
green, brown, or black ; streak un-
coloured, except in impure and partially
decomposed specimens ; H. 6 '5-7 '5 ; G.
3 1-4 -3.
Var. The garnets are variously sub-
divided, according to their chemical com-
position and colour, as follows : —
a. Grossularite. A lime-alumina gar-
net, of a light greenish colour.
b. Pyrope. A magnesia-alumina gar-
net.
c. Almandite, or Precious Garnet. An
iron-alumina garnet of a beautiful
red colour.
d. Common Garnet. An impure variety
of the foregoing, of a brownish
colour.
e. Colophonite. A lime-iron-alumina
garnet, of a yellowish colour.
f. Spessartite. A manganese-alumina
garnet.
g. Aplome. A lime-iron-alumina gar-
net, from Sweden,
h. Andradite. A lime-iron garnet,
i. Bredbergite. A Ifme-magnesia-alu-
mina garnet,
j. Ouvarovite. A lime-chrome garnet,
of an emerald-green colour,
k. Essonite. A lime-alumina garnet,
of a reddish-yellow colour.
1. Melanite. A lime-iron garnet, of a
black colour, &c.
The specimens hitherto found in Corn-
wall and Devon appear to be all either
common garnet or colophonite.
B. , etc.. In matrass unchanged • on C
the varieties containing much iron fuse
at from 3 to 5 to a dark 'magnetic bead ;
with borax or micro, gives the reactions
for iron ; the powder is slowly decom-
posed by HC1 more readily after fusion,
depositing gelatinous silica.
Comp. It is a complex anhydrous
silicate of various bases. The range of
composition in the various sub-species is
very great, viz. : —
GEMS.
GLAUCONITE.
51
Silica from 37'0 to 43'0
Alumina O'O 24'0
Peroxide of iron O'O 31 '3
Protoxide of iron O'O 39 '6
Lime O'O 371
Magnesia O'O 15'0
Oxide of manganese ... O'O 31 '0
Peroxide of chromium. O'O 24 '0
No analysis of a specimen from Corn-
wall or Devonshire is known to the writer.
Loc. Huel Cock Carn, Botallack,
Crown's Rock, Chycornish Carn, and
Roscommon Cliff (Figs. 3, 5, 25, 26, 31),
from 1-16 th to one inch across, in the
hornblende slate of the district, both
crystallized and massive ; near Lewellin,
embedded in carbonate of lime ; Cape
Cornwall Mine, in a tin capel (Fig. 5)
and macled, recently from l-10th to
l-3rd of an inch ; Rose Moddress, a little
west of Lamorna Cove, on a junction of
granite and slate ; St. Michael's Mount ;
Huel Trannack ; in greenstone between
Camborne and Tuckingmill, near Dol-
coath and North Roskear ; Carharrack ;
near Copper Hill Mine, Redruth, with
dark green epidote, very recently ;
Seal Hole Tin Mine, St. Agnes (Fig. 3);
near Lanlivery and Lostwithiel (black,
crystallized, and massive, with magne-
tite), specimens from this locality are
wow IE. the Museum of the Royal Insti-
tution of Cornwall ; Maudlin ; Terrace
Hill Quarry, near Callington ; Lustleigh;
Hay Tor ; Brent Tor ; on Dartmoor, in
granite ; Belstone Consols, in large crys-
tals, partly decomposed, &c. ; also Cum-
berland, Ireland, Scotland.
Obs. The Cornish garnets are asso-
ciated mostly with greenstone, either in
the rock itself, or in close proximity to
it. Most of them are of a dull brown
colour, and semi-transparent to nearly
opaque ; some of the St. Just garnets
formerly raised were of a light colour
and resinous appearance. (Colophonite?)
Angles.
dd = 120° Off nn' = 131° 48'
nn 146 27 dn 150 00
Gems. These are such mineral speci-
mens as are hard enough and have suffi-
cient beauty of colour to be used as
ornaments for the person. Fine speci-
mens of Garnet, Beryl, Topaz, Tourma-
line, and Quartz (rock crystals) are used
for this purpose. With the exception of
the rock crystals, or Cornish diamonds,
few specimens of these minerals have
been found in the two counties suffi-
ciently good to be so used.
Geodes. These are hollow stone balls,
with the inner surface usually lined with
crystals, some being occasionally de-
tached. Very fine crystals are sometimes
found so situated. Thus, some geodes of
partially decomposed galena from Beer-
f erris were found to contain fine crystals
of anglesitc.
GILBERT ITE.
[Margarodite. Talcite. Nacrite. Hy-
drous Muscovite.] Oblique (?), or more
probably Rhombic ; usually in compactly
aggregated scales ; friable ; translucent
to opaque ; lustre pearly ; white, grey,
yellowish, greenish ; H. 2-2 '5 ; G. 2 '6-2 '8.
£., etc. In matrass gives off water ;
on C alone becomes silvery white and
opaque, but retains its lustre ; scarcely
soluble in HC1 or HNO3 ; more readily
soluble in H2SO4.
Comp. A hydrated silicate of alumina,
containing small proportions of other
bases. The following analyses of Corn-
ish specimens indicate its composition ;
a. by Lehunt, a whitish silky specimen,
from a lode at Stenna Gwynn, St. Aus-
tell ; b. by Thomson, ditto : —
Silica 4515 ... 47;80
Alumina 4011 ... 32'62
Magnesia 1'90 ... 1'60
Lime 417 ... —
Soda ... 9'23
Protoxide of iron 2'43 ... 518
Water... 4'25 . 4'00
Totals 98'01 ... 100'43
Loc. Stenna Gwynn, St. Austell, with
fluor ; Carclaze Tin Mine ; Tregoniog-
hill and Tremearne, Breage, &c.
Obs. It is often spoken of as a
variety, species, or subspecies «.f mica.
It may, perhaps, be considered the crys-
talline form of Kaolin. It is associated
with the so-called china stone of Corn-
wall.
Girasol. See Quartz.
Glance Cobalt. See-Cobaltite.
Glance Copper. See Chalcocite.
GLA UCONITE.
[Green-earth. Kirwanite.] Amorphous,
botryoidal, or massive ; earthy ; brittle,
almost friable ; opaque ; dull or glim-
mering ; various shades of green, bluish,
or greyish ; streak somewhat lighter than
the colour; H. 0-2; G. 2 '2-2 '4.
B. , etc. In matrass yields much water
and darkens ; on C fuses easily to a dark
magnetic glass; partially soluble in
HC1.
Comp. Hydrated silicate of alumina
and iron, with often some potash or soda.
No analysis of an English specimen is
known, but foreign specimens contain
from 40 '0 to 52 '0 per cent, of silica, 5'0
to 12 '0 per cent, of alumina, 20 '0 to 25 '0
52 GLAUCOSIDEEITE.
GOLD.
per cent, of oxide of iron, O'O to 12 '0 per
cent, of potash, and4'0 to 10 '0 per cent,
of water.
Loc. Huel Coates (botryoidal); Brans-
comb cliff ; near Chard ; near Beer ; and
generally throughout the grecnsavd of
Devon. Also in many foreign localities.
Obs. The term is applied very loosely
to substances of very different composi-
tion. Probably some of the so-called
"green earth" is chlorite. The true
Glauconite analysed by Thomson was
from New Jersey, and contained 19 '0 per
cent, of lime.
Glaucosiderite. An old name applied
to various kinds of Mica, and also to
micaceous Vivianite.
Glimmer. An old name for the various
micas.
GOETHITE.
[Hydrous Oxide of Iron.] Rhombic ;
in tabular crystals, like Figs. 124, 326,
with some planes striated ; perfect cleav-
age parallel to a (brachydiagonal); also
acicular, capillary, or micaceous ; some-
times botryoidal, fibrous, columnar, ra-
diated, granular ; fracture conchoidal or
uneven ; translucent on thin edges ;
lustre sub-metallic ; adamantine, or
silky; yellowish, reddish, or blackish-
brown ; thin plates and fine needles red
by transmitted light ; streak yellowish -
brown; H. 5-5 "5; G. 4 1-4 '4.
B., etc. In matrass gives off water;
on C, in O F turns reddish, RF becomes
black and magnetic ; infusible, or fusible
with great difficulty on thin edges;
with borax and micro, gives Fe reac-
tions ; soluble in HC1, forming a yellow-
ish solution ; often leaves a slight insolu-
ble residue of silica.
Comp. Hydrated peroxide of iron.
The following is an analysis by Yorke of
a specimen from near Lostwithiel, the
sp. gr. of which was 4 '37 : —
Peroxide of iron 89 '55
Oxide of manganese 016
Silica 0'28
Water ... 10 '07
Total lOO'OG
With 90 '0 per cent, of peroxide of iron
and 10 '0 per cent, of water the formula
may be written FegHg or Fe.2O2Ho2,
Loc. Botallack, and other St. Just
mines, like Fig. 124, and in doubly
pointed flattened prisms, with some of
the faces striated, rough, or mamtnilated ;
Tincrof t ; Cam Brea ; Huel Druid ; Huel
Beauchamp ; Huel Buller ; Restormel,
in geodes (Figs. 124, 126, and other
forms); Tintagel ; Delabole ; Exmoor,
&c. ; also in Somerset, Scotland, Ger-
many, Russia, and many other foreign
localities.
Obs. It usually occurs in veins and
cavities, with quartz and limonite, of
which it is, perhaps, a crystallized
variety. It may be distinguished from
specular iron (hematite) and magnetite
by its yellowish streak, and by yielding
water when heated in a matrass ; from
rutile and brookite by its blowpipe
reactions.
Angles.
M M' = 94° 52' k k = 144° (XX
dd' 130 40 a b 90 00
The form a d M p s has occurred
at Botallack ; the forms a d p, a d m p
d M p s, d M p, a d M p e u r, d M p b,
adMpe, adMps, adMpes, adMpeslz,
&c. , are from Restormel ; some were not
less than two inches long.
GOLD.
[Native Gold.] Cubical, in cubes, octa-
hedrons, rhombic dodecahedrons, <fcc. ; or
usually in waterworn " nuggets " or
scales; also capillary, arborescent, disse-
minated ; m illeable ; fracture hackly ;
opaque ; lustre metallic ; various shades
of yellow ; streak yellowish and shining;
H. 2 '5-3 ; G. 14 '5-19 '5.
B., etc. In matrass unchanged, or
gives a slight sublimate when Tellurium
is present ; on C fuses easily to a bead
but is not otherwise changed ; insoluble
in HC1 or HNO3, but soluble in Aqua
Regia, forming a yellow solution.
< 'omp. Gold, containing variable pro-
portions of other metals, as Ag, Te, Pd,
Rh, Bi, Cu, Fe, &c. The following recent
analysis of a specimen from St. Austell
Moor is by Mr. D. Forbes, F.R.S., the
sp. gr. of which was 16 '5 : —
Gold 9012
Silver 9'05
Silica and oxide of iron ... 0 '83
Total lOO'OO
Loc. Carnon Valley, in stream tin
works. "There is a piece of gold in a
matrix of quartz from Carnon vale, in
the Royal Institution of Cornwall,
weighing lldwts. 6grs." (A Manual of
Mineralogy, Truro, 1825 ) This piece is
said to have been obtained in 1726. The
largest specimen ever obtained in Corn-
wall weighed more than eight guineas.
Treworda, Kenwyn ; Probus ; Ladock ; St.
Stephens ; St. Mewan ; St. Austell Moor,
and most of the tin stream works of
Cornwall and Devon, formerly, in small
quantities ; in a crosscourse at Huel
Sparnon, Redruth ; in gozzan at Nangiles
Mines, Kea; in veins at North Molton
GONIOMETER.
GRAPHITE.
53
and North Tawton, Devon. Traces are
often found in galena, pyrites, chalcopy-
rite, and other ores. Gold occurs in
a 'most every foreign mining district, but
especially in Australia, California, British
Columbia, the Ural, Transylvania, &c.
Obs. British gold very rarely exhibits
any crystalline face. It may be easily
distinguished from any mineral thought
to resemble it by its sp. gr. and blowpipe
characters, as well as its malleability
Goniometer. An instrument for mea-
suring the angles of crystals. Two kinds
are used by mineralogists : the contact
and the reflective goniometer. A very
effective contact goniometer for rough
measurements of the angles between
cleavage planes, &c , may be made by
fastening two straight slips of metal
together so that they work stiffly on a
pivot. The crystal to be measured is
placed in the an^le, and the two slips
adjusted as accurately as possible. The
angle may be read off by the aid of a
sector, or a common semi-circular pro-
tractor. The reflective goniometer is an
elaborate instrument. Its construction
and use is described in most general
works on mineralogy.
GOSLARITE.
[White Vitriol. Zinc Vitriol.] Rhom-
bic ; in prisms, with perfect brachydia-
gonal cleavage, usually acicular ; or mas-
sive, stalactitic, botryoidal, reniform, in-
vesting, pulverulent ; brittle ; fracture
conchoidal or uneven ; transparent to
translucent ; lustre vitreous ; colourless,
white, or tinged red, green, or blue, from
the presence of traces of cobalt, iron, or
copper; streak white; H. 2-2*5; G.
1-9-21.
/?., etc. In matrass melts at first;
then gives off a large quantity of water
which has an acid reaction ; leaves at
last a white or grey infusible residue,
which is yellow while hot ; on C the
same as in matrass, but deposits a white
incrustation if the RF be used; the
white infusible residue treated with
cobalt turns green ; easily soluble in
water ; the solution has a very nauseous
taste.
Gomp. Hydrated sulphate of zinc.
The following analysis of a Cornish spe-
cimen is by Schaub : —
Sulphuric anhydride 21 '64
Oxide of zinc 25*66
Lime TOO
Oxide of iron 017
Oxide of manganese 4*33
Silica 0-67
Water ... . 46 '50
Total . 99-97
With sulphuric anhydride 27 '87, oxide
of zinc 28'44, and water 43 '89 the for-
mula might be written ZnS + 7H2 or Zn
SO4 + 7H2O or SO2Zno"2 + 7OH2.
Loc. Formerly in acicular crystals in
a lode traversing the Tresavean and Tre-
thallan Mines, Gwennap, with quartz
and blende ; the cliffs under Huel Castle,
St. Just, with pearl spar and blende ;
found also in Wales, Germany, Hungary,
Sweden, France, Spain, &c.
Obs. It is usually found in old mine
workings, and is probably derived from
the decomposition of blende. Large quan-
tities are artificially produced for use in
dyeing.
Gossan. A miner's term for the loose
mixture of Quartz, Oxide of iron, and
other minerals often found on the "back"
of a lode.
Granite. A rock composed of Quartz,
Felspar, and Mica. The Cornish and
Devonshire granites often contain crys-
tals of black Tourmaline (schorl), and
sometimes of Cassiterite, Beryl, Topaz,
and other minerals. For a detailed de-
scription of these minerals see under
their names.
Granular. Made up of small grains.
Ex. Chalk.
GRAPHITE.
[Plumbago. Black Lead.] Hexagonal;
in flat six-sided tables, like Fig. 223, the
plane o striated parallel to alternate
edges ; cleavage parallel to o perfect ;
more commonly massive, reniform, fi-
brous, foliated, granular, compact, scaly,
or disseminated; sectile, thin plates or
fibres flexible ; fracture uneven ; very
unctuous to the touch ; opaque ; lustre
metallic ; dark steel grey ; streak greyish-
black and shining ; soft enough to mark
paper and soil the fingers; H. 1-2; G.
1*8-2 ; it is a perfect conductor of electri-
city.
£., etc. In matrass unchanged ; on C
infusible, burns away slowly without
flame or smoke ; usually leaves a very
little reddish ash, which with micro, or
borax gives Fe or Mn reactions ; insolu-
ble in HC1, HNO3, or H2SO4.
Comp. The purest varieties are almost
chemically pure carbon.
Loc. Grampound ; Boscastle ; Ker-
jiliack, near Penryn, in an elvan quarry;
Tuckingmill, in small lumps, in an elvan
course ; found also in Cumberland, Ire-
land, Scotland, and many foreign loca-
lities.
06s. It may be distinguished from
Molybdenite by its insolubility in a bead
of micro.; also by its streak on porcelain,
54
GREASY.
HARDNESS.
which is nearly black, but that of Molyb-
denite is greenish. It may be easily dis-
tinguished from Pyrolusite by its unc-
tuous feel, and from Antimonite and
Jamesonite by its infusibility.
Angles.
a a = 120° 00' ao = 90° 00'
Greasy. A variety of " lustre," well
seen in some varieties of serpentine.
Green Carbonate of Copper. See
Malachite.
Green Lead Ore. See Miraetite and
Pyromorphite.
Green Vitriol. See Melanterite.
Grey Antimony. See Antimonite.
Grey Cobalt. See Smaltite.
Grey Copper. See Chalcocite and
Fahlerz.
Grey Manganese. See Manganite.
Grey Oxide of Manganese. See Man-
ganite.
GYPSUM.
[Sulphate of Lime, Selenite, &c.]
Oblicfue ; often macled ; in tabular or
acicular ciystals, with perfect clino-
diagonal cleavage ; also compact, granu-
lar or massive ; tough j transparent to
nearly opaque; lustre vitreous, pearly,
or silky ; colourless, or white, yellow,
brown, &c. ; streak white, or much lighter
than the colour ; H. l'5-2 ; G. 2 "3-2 '4.
Var. Selenite is the name given to
crystallized specimens.
Fibrous Gypsum or Satin Spar is a
fibrous variety ; the same name is given
to a fibrous variety of carbonate of lime.
Alabaster is a massive, compact, or
granular variety, which often forms rock
masses of great extent.
B., etc. In matrass gives off water,
and becomes opaque if not previously
so ; on C fuses with difficulty ; with
fluor spar fuses easily to an opaline bead ;
the powder, after heating, if mixed with
water to a paste, "sets" to a hard mass ;
slightly soluble in water; almost insoluble
in acids.
Comp. Hydrated sulphate of calcium.
With sulphuric anhydride — 46 '51 per
cent., lime 32 '56, water 20 '93, the for-
mula may be written CaS + 2H2 or CaS04
+ 2H2Oor SO2Cao" + 2OH2.
Loc. Roscommon Cliff, St. Just ;
St. Minver, in nodular or concretionary
masses of volcanic rock (N. Whitley,
Journ. Roy. Inst. Corn); Branscomb,
and near Axmouth, in fissures of the
cliffs ; and other parts of Devonshire.
Obs. It is not unfrequently found in
steam boilers in the two counties. Some
fine crystals were obtained, years ago,
in a boiler at the East Tamar Mines,
Devon, and lately from a boiler from
Great Huel Busy, near Chacewater. The
large masses of so-called "Slipper Iron"
from Virtuous Lady Mine are probably
pseudomorphous after seleuite. Fig. 158
is a common form of selenite crystals.
A nqles.
M M == 111° 12' M 1 = 131° 00'
Mb 124 19 Ib 108 09
H.
Hackly. Covered with small wiry
points. The fracture of a piece of
native or artificially produced copper
is "hackly."
Haidingerite. See Berthierite.
Hair Pyrites. See MiUerite.
HALITE.
[Common Salt. Chloride of Sodium.]
Cubic ; in cubes variously modified, with
perfect cubical cleavage ; more usually
massive, fibrous, compact, stalactitic, or
granular ; brittle ; fracture conchoidal ;
transparent to translucent ; lustre vitre-
ous or resinous ; colourless, or white,
grey, blue, yellow, or brown ; streak
white ; H. 2-2-5 ; G. 2 "2.
£., etc. In matrass decrepitates and
gives off H.2O ; on C fusible at about 3,
colouring the flame yellow ; readily solu-
ble in water.
Comp. Anhydrous chloride of sodi-
um, NaCl, with chlorine 60 '34, sodium
39'66.
Loc. Pseudomorphous crystals were
found in a shallow cutting by the side
of the Taunton and Ilminster turnpike-
road, near Blackbrook ; and also asso-
ciated with the water-stone beds, in the
face of the cliff between Sidmouth and
Salcombe Mouth, by Mr. G. W. Ormerod,
F.G.S. (Rep. and Trans. Devon Assoc.,
vol iii., p. 78.)
06s. It may always be readily known
by its taste.
Hardness. A character of much im-
portance in the discrimination of miner-
als. The "hardness" of a mineral (H.)
may be conveniently expressed by com-
paring it with the following "scale of
hardness : " —
1. Talc. 6. Orthoclase.
2. Gypsum. 7. Quartz.
3. Calcite. 8. Topaz.
4. Fluor. 9. Corundum.
5. Apatite. 10. Diamond.
The " hardness " of a mineral may be
determined in different ways —
1st. By attempting to scratch it with
the minerals mentioned in the
above list, successively.
2nd. By passing a finely cut file over
the specimens, with a rather firm
pressure, three or four times.
HARSH.
HEMATITE.
55
3rd. By attempting to scratch the spe-
cimens with a knife.
Several trials should be made to ob-
tain certain results, and each method
should be tried, if possible. Thus, sup-
pose the specimen is a piece of Chalco-
cite, No. 2 (gypsum) fails to scratch it ;
but No. 3 (calcite) scratches its surface
readily. Next, reversing the method, it
is found that the specimen will scratch
No. 2 readily, but not No. 3. On trying
it with the file it is not rubbed away so
readily as No. 2, but more readily than
No. 3. It would be sufficient to set down
its hardness as 2'5. Easy as the method
is, some precautions should, nevertheless,
be observed. Thus, in a fibrous specimen,
a scratch directed across the fibres will
always indicate a lower degree of hard-
ness than the true one ; the scratch
should, therefore, be parallel to the
fibres, or, still better, on the surface of
a transverse fracture. Again : a sound,
undecom posed specimen should always
be selected, since the hardness of miner-
als is greatly affected by partial decom-
position rear the surface.
Many minerals are softer when first
obtained than after they have been kept
in dry cabinets for some time.
In crystals the edges and angles are
often considerably harder than the faces,
and of the primitive form than of the
modifications.
A series of substitutes has been ar-
ranged for use when a scale of hardness
is not at hand, i.e : —
1. May be readily scratched with the
nail.
2. Is scarcely impressed with the nail ;
does not scratch a piece of copper.
3. Scratches a piece of copper, but is
also scratched by it.
4. Not scratched by a piece of copper,
does not scratch glass.
5. Scratches glass slightly ; is easily
scratched with a knife.
6. Scratches glass easily ; is scratched
a little with a good knife.
7. Is not scratched with a knife, but
may be filed slightly.
8. Scratches rock crystal.
9. Scratches a topaz.
10. Scratches a ruby.
Harsh. Minerals which, like Actino-
lite, feel rough, are sometimes said to be
"harsh."
Haytorite. A variety of quartz oc-
curring in crystals which are pseudomor-
phous after Datholite is so called. It
occurred at the Haytor iron mines in
Devonshire, and at North Roskear, near
Camborne. See Pseudomorphs.
Heavy Spar. See Barytes.
Hedyphane. See Mimetite.
Heliotrope. See Calcedony (Blood-
stone).
HEMATITE.
[Specular Iron. Iron Glance, &c.]
Hexagonal ; crystals often tabular, and
frequently macled, like Figs. 226, 230,
232, 233 ; some faces striated or un-
even ; also columnar, granular, lamel-
lar, compact, stalactitic, botryoidal;
scaly, friable, or earthy ; brittle ; frac-
ture of compact varieties usually deep
conchoidal, of crystals uneven ; sub-
translucent to opaque; lustre metallic
or sub-metallic, splendant to glimmer-
ing ; dark steel-grey to iron-black, often
iridescent ; earthy varieties red or dark
reddish-brown; streak red to reddish-
brown ; often feebly magnetic ; con-
ductor of electricity ; H. 5 '5-6 '5, earthy
varieties sometimes soft: G. 4 '5-5 '3.
Var. a. Specular Iron (Elba Iron) is
a crystallized variety, with iron-black
colour and very brilliant lustre.
b. Micaceous Iron Ore (Scaly Red
Iron Ore) is a variety which occurs in
scales, or fine red or dark grey plates.
c. Kidney Iron Ore (Fibrous Red Iron
Oie) is a botryoidal or reniform variety,
with a radiated, and sometimes concen-
tric lamellar structure. A similar variety
of hydrous oxide of iron is also called
Kidney Iron.
d. Red Hematite is a compact and
massive variety.
e. Red Chalk, Red Ochre, and Reddle
are impure earthy varieties, often very
soft.
f . Jaspery Iron Ore is a kind of quartz
containing a large proportion of oxide of
iron.
B., etc. In matrass no change, or be-
comes somewhat darker in colour ; on 0
infusible; if powdered and strongly
heated becomes magnetic, and darkens
in R F ; with borax and micro, gives Fe
reactions ; soluble more or less readily
in warm HC1, forming a yellowish solu-
tion.
Comp. Anhydrous peroxide of iron.
Pure specimens contain of iron 70 '0 per
cent., oxygen 30 '0 per cent., wheti the
formula is Fe2 or Fe2O3.
Loc. Specular Iron — Restormel ; Huel
Maudlin, near Lostwithiel , Huel Beau-
champ, ne;>r Redruth ; Tincroft, Carn
Brea, Dolcoath, East Pool, and other
mines in Illogan and Camborne ; Botal-
lack (Fig. 223), with aragonite ; Boscas-
well ; Parknoweth ; Huel Owles ; Carn-
yorth ; Huel Bellon ; Huel Maggot ;
Hennock, near Chudleigh ; Lustleigh ;
Birch Tor Mine, near North Bovey ; and
other localities in Devon.
56
HEMIHEDEAL.
HYPEESTHENE.
Micaceous Iron Ore— Restormel ; Carn
Brea ; Tincroft ; Huel Druid ; Levant ;
Little Rounds ; and other localities
Kidney Iron Ore and Red Hematite —
Botallack, Levant, and most of the St.
Just Mines ; Huel Rave and Huel Rose,
near Helston ; Treluswell, near Penryn,
with magnetite ; Ladock, near Gram-
pound ; Davidstow ; Birch Tor Mine,
near North Bovey ; Lustleigh ; Buckfast-
leigh ; Hennock, near Chudleigh ; and
several places on Dartmoor ; Huel Forest,
near Okehampton ; Bratton Fleming,
Shirwell ; East Down ; Viveham, George-
ham, and other places near Barnstaple ;
Orleigh Court, near Bideford, forming a
breccia with chert and flint in greensand ;
in greensand at Buckland Brewer ; II-
fracombe ; Combemartin ; Lynton ; West
Down ; North Moulton ; Brixham, &c.
Red Ochre — Ladock ; Davidstowe ; and
many other of the above-named localities.
Red Chalk— Little Bounds, St Just ;
Ladock ; and Broad Down, Farway, near
Honiton ; Peak-hill, near Sidmouth.
The chief forms of Hematite are found
in most mining districts.
Obs. Hematite may be distinguished
from goethite and limonite by its being
anhydrous ; from these ores and magne-
tite by the colour of its streak. The
earthy varieties, however, often yield
a little water when heated in a matrass,
and sometimes have a brownish streak.
Angles.
RR' = 93° 50' uu = 143° 07'
R o 122 30 u o 158 35
Hemihedral. A term applied to crys-
tals which have only one-half of their
planes developed. Thus, the tetrahedron
(Fig. 33) is the hemihedral form of the
octahedron (Fig. 1). If equal slices were
to be taken from each alternate face of
the octahedron until four of the faces
were entirely destroyed, the resulting
figure would be the tetrahedron,
Hemitrope. A made.
Hepatic. Liver-like. A term applied
sometimes to a peculiar form of mineral,
when it has much the same meaning as
reniform, and also to a peculiar colour
observed in some minerals. Thus, some
varieties of pyrites readily decompose to
a liver-coloured mass.
HISINGERITE.
[Thraulite.] Amorphous; massive and
reniform, or compact in concentric
crusts ; with rough surfaces ; brittle ;
fracture conchoidal or uneven ; opaque ;
lustre resinous, inclining to adamantine ;
brownish or bluish-black ; streak yellow-
ish-brown or pale reddish-brown: H.
3'5-4; G. 174-3.
B., etc. In matrass yields much
water with an acid reaction ; on C alone
fuses with difficulty to a reddish, steel-
grey, or black magnetic bead ; with
borax and micro, gives Fe reactions ;
partially soluble in HC1 or HNO3, leav-
ing a gelatinous residue of silica.
Com.}). Hydrated silicate of iron. The
proportion of silica varies from 27 '0 to
36 '0 per cent., proto-peroxide of iron
44-0 to 53-0 per cent., water 10 '0 to 21 '0.
A mean of three analyses of a Cornish
specimen (sp. gr. 1"74), by Professor
Church, gave—
Peroxide of iron 52"94
Silica 3614
Ph osphoric anhydride trace
Magnesia trace
Water 10'49
Total 99*57
With peroxide of iron 50 '6, silica 38 '0,
water 11 '0, the formula might be written
Fe22Si2H.2 or Fe.2O32SiO2 + 2H2O (oxygen
ratio = 3.4.2).
LOG. Cornwall (Huel Gorland?), on
Autunite ; also on iron pyrites, in cavi-
j ties, with Limonite, Vivianite, and Cron-
| stedtite, probably from another locality.
Obs. It was obtained from Mr. Tailing
in the first instance, by Professor A. H.
Church, who identified it, it having been
mistaken for Beraunite.
Holohedral. A term used in opposi-
tion to "hemihedral," which see.
Hornblende. See Amphibole.
Horn Lead. See Cromfordite.
Hornstone. See Calcedony.
Horseflesh Ore. See Erubescite.
Hydrate. A compound of an oxide
with water, or a metal with hydroxyl.
Thus the hydrate of the oxide of copper
(cupric hydrate) may be written CuOH2
as a compound of oxide of copper with
water ; or CuH2O2 or CuHo2, in which
it is looked upon as a compound of cop-
per with hydroxyl.
Hydrated. Containing water as a con-
stituent part, and not merely as external
moisture. Water which is given off at a
temperature above 100° C is usually con-
sidered to be water of hydration.
Hydrofluoric Acid. See Fluorine.
Hydrous Oxide of Iron. See Limo-
nite and Goethite.
HYPERSTHENE.
Oblique ; crystals usually imperfect
and imbedded, when perfect usually
somewhat like Fig. 160 (Pyroxene, with
which Hypersthene is isomorphous); one
perfect cleavage, often curved, or
ICELAND SPAE.
INDURATED.
57
striated ; another at right angles, im-
perfect ; fracture uneven ; translucent
to opaque ; lustre vitreous or resinous,
usually pearly or sub-metallic on cleav-
ages ; grey, green, red, yellow, brown,
black ; streak white or grey : H. 4-6 ; G.
3-2-3U
Var. 1. Hypersthene proper has very
dark colours, and often a greenish-grey
strpak ; H. 6 ; rather readily fusible.
2. Bronzite colours dark, and inclin-
ing usually to brown ; white streak ; H.
5-6 ; almost infusible ; often brittle.
3. Diallage. Colours usually light ;
white streak ; H. 4 ; often easily fusible.
4. Hypersthene rock, Diallage rock,
Gabbro, &c., are names given to rock
masses, composed largely of some form
of hypersthene, with a great deal of fel-
spar, as in the cliffs at Coverack Cove
and the boulders on Cronsa Downs.
£., etc. In matrass no change ; on C
alone usually fusible to a dark magnetic
globule, or enamel ; with soda and borax
gives the reactions for iron, and some-
times those of manganese ; insoluble in
HC1 or HN03.
Comp. Anhydrous silicate of magne-
sia, iron, arid lime ; bat of very variable
composition.
Loc. Coverack Cove (Bronzite?), Ky-
nance Cove (Diallage?), and other parts
of the Lizard district; St. Cleer (?).
Hypersthene occurs in Scotland, Nor-
way, Sweden, Italy, North America, &c.
Obs. Hypersthene should, perhaps,
be included with pyroxene and amphi-
bole, in one large group, only separable
into sub-species. The chemical composi-
tion seems to be in all, too variable to
serve as a means of classification in
species, and they are isomorphous with
each other.
I.
Iceland Spar. See Calcite.
ILMENITE.
[Manaccanite. Titaniferous Iron. Ti-
tanite. Iserine. Kibdelophau, &c.] Hex-
agonal ; in tabular crystals, somewhat
like Figs. 200, 20], and 230, but with
curved faces ; or drusy ; also massive,
granular, or disseminated ; brittle ; f i ac-
ture conchoidal or uneven ; opaque ;
lustre metallic or sub-metallic, brilliant
to glimmering; iron-black, brown, or
steel-grey ; streak reddish-brown to
black ; sometimes slightly magnetic ;
H. 5-6; G. 4-6-5-0.
Var. a. Ihnenite occurs crystallize 1 or
massive.
b. Manaccanite was a term given to
the grains of titaniferous iron-sand found
at Manaccan.
c. Iserine is the term applied to a dark
sand of similar composition, fouud at
Iserweise, in the Kiesengebirge.
.B., etc. In matrass unchanged ; on C
unchanged, or turns brown ; with micro,
or borax gives the reactions for Ti; the
fine powder is slowly soluble in concen-
trated HC1 ; the concentrated solution
will, after a time, yield a precipitate of
titanic anhydride after dilution and
boiling ; imparts a blue colour to H2SO4
if boiled in it.
Comp. An anhydrous compound of
the oxides of titanium and iron. Of the
following analyses of Cornish specimens
a. was by Klaproth, b. by Gregor, c. by
Lampadius : —
a. b. c.
Oxide of titanium... 45 '25 45 '00 43 '5
Oxide of iron Sl'OO 46'00 50'4
Oxide of manganese 0*25 trace 0'9
Silica 3'50 trace 3'3
Alumina — — 1"4
Total 100-00 91-00 99'5
With 48 '0 per cent, of titanic anhydride
and 52 '0 per cent, of ferric peroxide the
formula may be Ti2Fe2 or Ti2O3-HFe2O3
or TiFeO3.
Loc. Manaccan, in the bed of a rivu-
let, as a black sand ; Gwendra, near
Coverack, disseminated, in diallage rock ;
Lannarth, near St. Keverne, in a stream
as a dark sand ; recently at Porthalla,
in a ferruginous deposit, both massive
and crystallized. The crystals were len-
ticular, with curved faces, and varying
from l-10th to i of an inch in diameter.
Obs. It may most readily be distin-
guished from Hematite by its dark brown
streak and reactions with micro.
Incandescent. Glowing ; combustion
without flame ; when charcoal is heated
before the blowpipe it glows, but rarely
bursts into flame. This is incandescence.
Incrustation. A term applied to the
dep-sit which is formed on the cool part
of a charcoal or tire-clay support when
ores of arsenic, antimony, or lead are
heated. It may always be driven away
by directing the blowpipe flame on the
part, and in this manner may be easily
distinguished from the white ash left by
the combustion of some varieties of char-
coal.
Indigo Copper. See Covellite.
Indurated. Hardened. Talc, Kaolin,
and other minerals seem sometimes to
be greatly hardened wnen iu contact
58
INFUSIBLE.
JAMESONITE.
•with igneous rocks, as if baked. They |
are then said to be indurated.
Infusible. That which cannot be fused j
or melted. Minerals are said to be in- j
fusible if they cannot be fused by means !
of an ordinary blowpipe flame, although I
they may be mostly fused by using the j
oxy-hydrogen blowpipe.
Investing. A term applied to minerals
which occur spread in a thin coating over
the surface of some different kind of
mineral or rock.
Iridescent. Exhibiting colours some-
thing like those of a rainbow.
Iridescent Copper Pyrites. See Chal-
copyrite (Peacock Copper).
Iris. See Quartz.
Iron Flint. See Quartz.
Iron Glance. See Hematite (Specular
Iron).
Iron Mica. See Hematite (Micaceous
Iron Ore).
Iron Nickel Pyrites. See Pentlandite.
Iron Ochre. See Hematite and Limo-
nite.
Iron Pyrites. See Pyrites.
Iron Rutile. See Goethite.
Iron Spar. See Chalybite.
Isomorphism. " Similarity in crystal-
line form exhibited by substances of
similar chemical constitution." Thus
the following mineral carbonates crystal-
lize in forms having a very great resem-
blance to each other, all being hexagonal,
and their primary or cleavage rhombohe-
drons having faces similarly inclined to
to each other, and varying only from
105° 03' to 1079 54' :—
Calcite CaC03 = 105 '03
Dolomite (MgCa)CO3 10615
Diallogite MnCO3 106'51
Chalybite FeCO3 107 '00
Mesitine Spar (FeMg)CO3 10714
Magnesite MgCO3 107 '25
Calamine ZnCO3 107 '54
A similar group of isomorphous carbo-
nates, crystallizing in the rhombic sys-
tem, is the following, the angles being
those of the prisms : —
Aragonite CaCO3 = 116° 10'
Cerussite PbCO3 117 14
Strontianite SrCO3 117 19
Witherite BaCO3 118 30
Similar groups of isomorphous minerals
are known in each system of crystalliza-
tion, when it is found that there is a ten-
dency for one member of a group to take
the place of another in a compound, thus
leading to a passage from one to another.
In fact, it seldom happens that one
member of an isomorphous group is quite
free from traces at least of another. For
further information on this interesting
subject see the works of Mitscherlich ;
Frankenheim's Systeme der Krystalle ;
or Brooke and Miller's Elementary In-
troduction to Mineralogy, 1852.
ISO PYRE.
Amorphous ; compact ; brittle ; frac-
ture conchoidal or uneven ; translucent
on thin edges, or opaque ; lustre vitreous
or dull; greyish or velvet-black, some-
times with reddish spots ; streak pale
greenish-grey; H. 5 '5-6 '5; G. 2 '9-3;
slightly magnetic.
£., etc. In matrass not changed ; on
C fuses readily to a magnetic globule,
sometimes colouring the tip of the flame
greenish ; with borax and micro, gives
Fe reactions ; imperfectly decomposed
by HC1 or HNO3, leaving a deposit of
silica ; the powder is decomposed by
strong solution of carbonate of potash.
Comp. Anhydrous silicate of iron,
alumina, and lime (?). The following
analysis of a specimen from St. Just was
made by Turner : —
Peroxide of iron 20 '07
Alumina 13'91
Lime 15'43
Oxide of copper 1'94
Silica . . 47-09
Total 98*44
Loc. Huel Carne, St. Just, in masses
of several inches in length, in granite,
associated with Cassiterite and Tourma-
line ; it is also said to have been found
near St. Ives.
Obs. In appearance it is not unlike
Obsidian, but less lustrous. It has been
thought to be an impure variety of opal
or jasper.
J.
Jade. A substance which has some-
times been so named is described as
Saussurite, which is itself perhaps only
a variety of Pyroxene. See Saussurite.
JAMESONITE.
Rhombic, usually in aggregations of
imperfectly formed acicular prisms, with
a perfect basal cleavage at right angles
to the prismatic faces ; or fibrous, co-
| lumnar, or massive ; sectile ; opaque ;
1 lustre metallic ; dark steel grey ; streak
black, or very dark; H. 2-2 %5; G. 5 '5-5/8.
Var. Feather ore is a variety which
occurs in soft masses, with interlacing
fibres, like felt.
B., etc. In matrass decrepitates, and
1 yields a reddish or yellowish sublimate ;
i on C fuses at 1 to a dark mass, which is
• partly absorbed by the charcoal ; deposits
JASPER.
KALINITE.
59
a yellow incrustation ; may be en-
tirely volatilized in O F, except a little
infusible slag, which gives Fe or Mn re-
actions ; in EF yields, after a good deal
of blowing, a malleable bead of lead ;
decomposed by warm HC1, leaving a
white ppt.
Comp. It is an anhydrous sulphide of
lead and antimony. The following analy-
ses, by H. Rose, are all of Cornish spe-
cimens : —
a. b. c.
Lead 4075 40'35 3871
Antimony 34 '40 33 '47 34 '90
Sulphur 2215 nt. det. 22 '53
Iron 2-30 2'96 2'65
Copper 013 0'21 019
Zinc... , — trace 074
Total 9973 — 9972
"With lead = 43 '6, antimony 36 '2, and
sulphur 20 '2, the formula might be writ-
ten Pb3Sb4S9 or 2PbS Sb2S3 + PbS.
Loc. Near Padstow ; Port Quin Cliffs,
and Trevinnock, near Endellion, with
bleinierite ; Port Isaac, Pendogget, Huel
Lee, Calstock ; Huel Boys ; Tintagel ; found
also in Spain, Hungary, Siberia, Brazil, &c.
Obs. It usually occurs with other ores
af antimony. It may be distingished
from antimonite by its basal cleavage, yel-
low incrustation when heated on charcoal,
and by its yielding a bead of Pb in EF.
JASPEE.
Amorphous ; tough ; fracture conchoi-
dal, uneven, or splintery ; opaque ;
lustre resinous or dull ; sometimes white,
but more usually grey, yellow, red,
brown, green, or black, sometimes mot-
tled of various colours ; streak white or
slightly coloured; H. 6-7; G. 2'6-3'0.
Var. a. Eibbon Jasper has the colour
arranged in stripes, or bands.
b. Lydian Stone, Tin Flint, Touch-
stone, or Basanite, is of a velvet-black
colour, and has a flat conchoidal fracture.
It is sometimes placed with Calcedony.
c. Bloodstone seems tobe partly Jasper
and partly Calcedony. It is of a dark
green colour, spotted with red.
d. Eisenkiesel, or Iron Flint, is a
brown and somewhat earthy variety.
B., etc. In matrass unchanged, or
gives off a little water ; on C infusible ;
with soda fuses readily to a coloured
bead, with much effervescence ; insoluble
in HC1, HN03, or H2SO4.
Comp. Anhydrous silica. It usually
contains, however, a small proportion of
water, and a variable proportion of per-
oxide of iron, and other oxides.
Loc. Botallack, Huel Owles, Levant,
Cape Cornwall, Huel Spearn, Little
Bounds, Huel Stennack, and other mines
in St. Just, of various colours, as red,
black, green, &c. ; Ding Dong, Madron ;
Marazion Beach ; Looe Bar ; Tremearne ;
North Eoskear, Dolcoath (red and black);
Eedruth; Huel Unity; St. Austell; Tru-
goe ; Huel Maudlin ; in greensand at
Buckland Brewer ; Ivybridge ; Doddis-
combleigh; Blackdo wn -hills ; Brent Tor;
Okehampton ; near Exeter ; Haldon,
near Teigiimouth, pale red; and many
other places in the two counties. Very
fine masses of Jasper are obtained from
Egypt, Italy, Germany, &c.
Obs. It can only be regarded as an
impure mixture of crystalloid and colloid
silica, with various metallic oxides. Por-
celain Jasper, or Porcellanite, is of quite
a different composition ; it is simply a
greatly hardened (baked?) clay.
Jaspery Iron Ore. A siliceous variety of
Hematite, or a very ferruginous Jasper.
JOHANNITE.
[Uran-VitrioL] Oblique; in small
flattened prisms, reniform masses, or
druses ; transparent to opaque ; lustre
vitreous ; emerald or yellowish-green ;
streak pale green; taste bitter and
astringent ; H. 2-2 '5 ; G. 319.
B. , etc. In matrass yields water with
acid reactions, and turns brown ; on C is
fusible at first, but leaves finally a dark
infusible residue ; with borax and micro,
gives the reactions for Uranium ; slightly
soluble in H2O.
Comp. Hydrous sulphate of Uranium.
Loc. Johannite has, perhaps, occurred
at South Huel Basset, in transparent,
bright yellow crystals, with other ores
of Uranium. (See Trans. Eoy. Geol. S«c.
Corn., vol. vii., p. 86.) The true Johan-
nite occurs in Germany and the United
States.
Obs. It is probably a product of the
decomposition of the ores of Uranium.
Its solubility in water would of itself
account for its rarity in a wet county
like Cornwall.
KALINITE.
[Alum. Potash Alum.] Cubical ; crys-
tals usually like Figs. 1, 2, 3, or com-
binations of these ; generally in crusts,
fibrous masses, or as an efflorescence ;
fractnre conchoidal or uneven ; trans-
parent or translucent; colourless, white,
or slightly tinted with green, yellow, or
blue ; streak white ; taste sweetish-
astringent ; H. of compact specimens
2-2-5; G. 175-1-9.
60
KAMPYLITE.
KEKATE
jB., etc. In matrass melts at first,
yields a large quantity of water with acid
reaction ; on C the same, and gives off
SO2 ; the white residue becomes blue if
treated with Co ; soluble readily in water.
Comp. Hydrated sulphate of potash
and alumina. "With sulphuric anhydride
3376, alumina 10 '82, potash 9 '95, water
45 '47, its formula may be written
A12 2K 43 + 24Ha or S4O8Ko2 Al2ovi +
240 H2.
Loc. It is said to occur in clay at
Chudleigh, in Devon (Greg'and Lettsom,
p. 71).
Obs. It is extracted from shales in
large quantities in Yorkshire, near
Whitby, and other places.
Kampylite. See Mimetite.
Kann. See Fluor.
Kaolinite. Dana. Rhombic, appear-
ing as hexagonal scales under the micro-
scope. Perhaps may be found in the
Cornish and Devonshire Kaolins.
KAOLIN.
[China Clay, Lithomarge, &c.] Amor-
phous ; massive, in beds, veins, or disse-
minated ; should, perhaps, be regarded
rather as a rock than a mineral ; fracture
earthy ; sectile, brittle, or friable ;
opaque ; dull ; adherent ; unctuous or
plastic while moist, sometimes meagre
when dry ; white, grey, or bluish, yel-
lowish, brownish, &c., from various
impurities ; streak like colour : H. 1-3 ;
G. 1-8-27.
Var. a. China Clay is the pure white
variety, used for thebest kinds of pottery.
b. Lithomarge is a peculiar indurated
variety, with H. 2-2 '5 : G. about 2 '6 ;
sometimes pyro-phosphoric.
c. Carnat is a flesh-coloured variety,
containing a good deal of iron.
B. etc.. In matrass gives off water ; on
C is infusible, and often loses colour;
trente-1 with Co turns blue; not readily
decomposed by HC1 or HNO3.
<?o>np. Hydra ted silicate of alumina,
with very often potash. Of the following
analyses a. was from Breage, analysed
T>y Dr. B.ase; b. from St. Stephens,
dittu ; c. from Devon, hy Berthier ; d.
from Dartmoor, by Fownes : —
a. b. c. d.
Silica 4015 39 55 50 '51 47'20
Alumina 3S'20 38 '05 3818 38'80
Peroxide of
iron — trace
Magnesia 175 1'45 — 0'24
Potash & loss 9-50 870 — 176
Water 11 -65 12'30 11 "02 12'00
Total 99-23 100D5 9971 100130
e. is the analysis of a specimen from
Devonshire ; f., from Dartmoor; g., a
kaolin earth from Plympton ; h. , a yel-
lowish-white lithomarge, with peach-
coloured veins, from Cook's Kitchen, by
Reeks (Trans. Roy. Geol. Soc. Corn.,
vol. vii., p. 76):—
e. f. g. h.
Silica 44-26 44'25 40'9 48'3
Alumina 38'81 36'81 44'5 36'4
Peroxide of iron — — • — 0'8
Lime & potash — 2 '20 — —
Water 1274 1270 15'3 14'5
Total 95-81 95'96 1007 100.0
With silica 46 7, alumina 41 1, water
12 '2 the formula may be written 2A12
3Si + 3H2 or 2(Al203SiO2) + SiO2 + 3H2O
or Si3(Al2ovi)2-i-3OH2.
Loc. a. China Clay— Balleswidden,
and other St. Just mines ; Tregoning-
hill, Breage; Vogue, near St. Day; East
Huel Damsel; St. Stevens and St. Den-
nis, Carclaze, and many other places near
St. Austell ; Chy tane, St. Enoder ; Cligga
Head, St. Agnes ; Great Dowgas ; Bovey
Tracey ; Dunscomb-hill, near Sidmouth ;
Plympton ; Fownes ; on Dartmoor ; and
' many other places in Cornwall and
! Devon.
b. Lithomarge — Balleswidden, and
i other mines at St. Just ; near St. Ives ;
| Cook's Kitchen, Tin croft, Dolcoath, Cam
| Brea, and other mines near Camborne ;
Huel Druid ; Huel Basset ; West Basset ;
South Huel Frances ; Carharrack ; Ting
Tang ; West Huel Jewell ; St. Blazey ;
| in amorphous yellow masses with agate
| at Hay Tor ; with apatite and tourma-
line at Bovey Tracey.
Obs. Kaolin is a substance of immense
importance in the arts. In an impure
form it probably composes all the clays
of the earth's crust, and when indurated
| forms xlates and shales. It should rather
be described as a rock than a mineral.
Kassiterite. See Cassiterite.
KERA TE.
[Kerargyrite. Horn Silver.] Cubic;
in small modified cubes, octahedrons, or
rhombic dodecahedrons (Figs. 1, 2, 3, 8,
to 16); sometimes acicular, columnar,
massive, or investing ; sectile or mallea-
ble ; fracture conchoidal . or uneven ;
translucent to almost opaque ; resinous
or waxy ; pearl-grev, greenish, bluish,
or brown, especially on exposure to
light ; streak white and shining ; H.
1-1-5; G. 5-3-5-6.
jB., etc. In matrass melts without
further chanae ; on C fuses readily, and
is easily reduced to a malleable bead of
KILLAS.
LEPIDOLITE.
61
silver ; if mixed with oxide of copper
tinges the flame bright blue ; if moist-
ened and rubbed on a plate of polished
iron, metallic silver is deposited ; insolu-
ble in HC1 or HNO3 ; slowly soluble in
ammonia, and re-precipitated by HC1.
Comp. Anhydrous chloride of silver.
Pure specimens contain 75 '34 per cent,
of silver and 24 '66 per cent, of chlorine,
the formula will therefore be AgCl.
Loc. Huel Herland ; Huel Alfred and
Huel Ann, Phillack ; Huel Duchy, in
brown gossan, in forms resembling Figs.
8 and 12 ; Huel St. Vincent, near Cal-
stock, with native silver ; Silver Valley ;
Huel Brothers ; Huel Mexico and Huel
Basset, Perranzabuloe, crystallized and
massive ; Dolcoath ; North Dolcoath
(Figs. 1, 8, 12); Botallack, Levant;
found also in Ireland, and in many
foreign silver producing districts.
Obs. In Cornwall it usually occurs
with other ores of silver, hydrous oxide
of iron, quartz, and ores of copper. Mr.
Came observes, "It has not yet occurred
in any Cornish mine whose lode traverses
granite." (Trans. Roy. Geol. Soc. Corn.,
vol. vii., p. 87.)
Angles. Same as Cuprite.
Killas. A Cornish term for the al-
tered clay-slate of the district.
Klinoclase. See Clinoclase.
Kupferindig. See Covelline.
Kupfernickel. See Niccolite.
Lamellar. Minerals which can be
split up into plates are so called. Ex.
Barytes, Fluor, &c. Foliated is the
same, but the plates are very thin.
LANGITE.
Rhombic ; crystals usually small and
short, in forms not unlike those of ara-
gonite ; also fibro-lamellar, concretion-
ary, or investing ("rippled"); the
surface sometimes earthy; transparent
or translucent ; lustre of crystals vitre-
ous, of thin crusts silky ; colour blue or
greenish-blue ; H. 2 '5-3, crusts softer ;
G. 3-48-3-5.
B., etc. In matrass gives off water
with acid reaction, and turns black ; on
C gives off a sulphureous odour, and
easily yields a bead of copper; soluble
in HC1.
Comp. Hydrated basic sulphate of
copper. The following analyses are all
very recent : —
a. b. c. d. e. f.
Sulphuric
anhydride 16 '42 1677 1679 1672 16'88 16'2
Oxide of
copper .. 65-82 65'92 67'48 67'31 67 '88 681
Lime — 0'83 — — — 0'5
Magnesia — 0'29 — — — —
Water .. 18'32 16'19 1573 16'25 15'53 15 '2
Total 100-56 lOO'OO 100-00 100-28 100-29 lOO'O
a. is an analysis by Maskelyne, b. by
Pisani, c. by Church, d. and e. by War-
rington, f. by Tschermak. With sul-
phuric anhydride 16 '4, oxide of copper
65 '2, and water 18 "4 the formula may be
written 4Cu, s", 5H2 or CuSO4+3CuH2O2
+ 2H2O or SO2Cuo"3CuHo2 + 20H2.
Loc. Copper Hill Mine and Huel Bas-
set, Redruth ; East Pool, Dolcoath, and
other mines near Camborne.
U bs. It is found on killas, in brilliant
minute macled crystals of a beautiful
deep blue colour, or "rippled" crusts of
a greenish-blue tint and somewhat earthy
appearance. The name Devilline was
at first given to a very similar mineral.
(See Comptes Rendus for 1864, pp. 813,
633 ; see also Journ. Chem. Soc., II.,
iii., 87; Phil. Mag., IV., xxiii., p. 306,
1864; Phil. Mag., IV., xxii., p. 473,
1865 ; Chem. News, x., 263, 1864, &c.)
Lapis Ollaris. See Steatite (Potstone.)
Lazurite. See Chessylite.
Lateral. This term is applied to the
secondary axes in the pyramidal and
hexagonal crystallographic systems.
Lead Earth. A term applied to the
earthy variety of Cerussite.
Lead Glance. See Galena.
Lead Ochre. See Plumbic Ochre.
Lead Spar. See Cerussite.
Lenticular. Lens-shaped. Crystals
which are nearly flat circular scales, but
slightly convex above and below. Ex.
Some specimens of Hematite and Ilmenite.
Lenticular Arseniate of Copper. See
Liroconite.
LEPIDOLITE.
[Lithia Mica.] Rhombic; rarely In
prisms, with perfect basal cleavage ; usu-
ally in pinkish granular masses, inter-
spersed with small flexible translucent
scales ; lustre pearly ; peach-blossom red
to pearl-grey, white, or brownish ; crys-
tals dichroic; H. 2'3; G. 2 '8-3.
/?., etc. In matrass scarcely altered;
on C fuses more or less readily to a trans-
parent and nearly colourless glass ;
colours flame red, especially if just mois-
tened with HC1 or H2SO4, or mixed
with KHSO4 ; insoluble in HC1, HNO3,
or H2SO4, but readily decomposed by
HC1 after ignition.
62 LEPIDOMELANE.
LIBETHENITE.
Gomp. Anhydrous silicate of alumina,
iron, potash, and lithia, with some flu-
oride. Of the following analyses of
Cornish specimens a. is by Turner, b.
and c. are by Rammelsberg, d. is a recent
analysis by Haughton, of a white, pearly
specimen, from Tremearne, in Breage,
which occurred in rhombic tables of 60°
and 120°:—
a. b. c. d.
Silica 50-82 5170 52'40 47 '60
Alumina 21 '33 26 76 26 '80 27 '20
Protoxide of iron . . 9'08 — —
Peroxide of iron .... — — — 5 '20
Oxide of manganese trace T29 T50 T20
Lime — 0'40 — 0'45
Magnesia — 0'24 — trace
Potash 9-86 10'29 914 10"48
Soda — 1-15 — 0-72
Lithia 4'05 T27 4'85 114
Fluorine 4 '81 7'12 418 —
Fluosilicon — — — 5 '68
Phosphoric anhy. .. — 016 — —
Total 99-95 100"38 98'87 99'67
Loc. St. Michael's Mount, in pale
peach-coloured and silvery hexagonal
scales ; Trewavas Head and Tregoning-
hill, Breage, in white rhombic scales ;
Lanarth, near Redruth, nearly white ;
near Bovey Tracey, in white silvery
plates, &c. ; it occurs also in Scotland,
Ireland, and many foreign localities.
LEPIDOMELANE.
Rhombic ; in six-sided plates, or
rhombs of 60° and 120°, with perfect
basal cleavage ; flexible and elastic ;
translucent or opaque ; lustre sub-me-
tallic, adamantine, or vitreous ; dark
brownish or greenish-black ; dichroic ;
streak greenish ; H. 3'0 ; G. 3'0.
B. , etc. In matrass no change ; on C
melts readily to a dark magnetic globule ;
with borax forms a greenish glass ; de-
ed by HC1, leaving pearly silica.
Gomp. Silicate (with fluoride) of alu-
mina, iron, potash, and lithia. Of the
following analyses a. is a Cornish speci-
men (brown), by Turner ; b. a very dark
coloured specimen from Cam Bosavern,
recently analysed by Professor Haughton,
F.R.S.:—
27-06
Silica 40-06
Alumina 22'90
Protoxide of iron . . )
Peroxide of iron . . . . j
Oxide of manganese .. 179
Lime —
Magnesia — .. 1'07
Potash 4'30 .. 976
Soda — .. 0'99
Lithia 2'00 .. 171
Fluosilicon — . . 3'04
Fluorine 271 . —
b.
39-92
22-88
15-02
2-32
1-40
0-68
Total 100-82 . . 987£
It will be seen that lepidomelane differs
mainly from lepidolite by the smaller
quantity of silica, and the presence of a
large proportion of iron.
Loc. Carn Bosavern, St. Just, and
many of the Cornish granites.
LEUCOPYRITE.
[Arsenical Pyrites. Lolingite, &c.]
Rhombic ; the usual combination is much
like Fig. 115, without the plane O ; one
perfect cleavage ; more usually massive ;
compact, granular, or columnar; some-
times disseminated ; brittle ; fracture
uneven ; opaque ; lustre metallic ; sil-
very-white to steel-grey, often a yellow
or brown tarnish ; streak greyish-black ;
H. 5-5*5; G. G-9-7'4.
B. , etc. In matrass gives an abundant
white or yellowish sublimate, which is
dark and metallic below ; on C fuses
readily to a black magnetic mass, depo-
siting a white incrustation, and giving
off copious arsenical fumes ; with borax
gives Fe reactions ; insoluble in HC1 ;
soluble in HNO3, with a separation of
As203.
Gomp. Arsenide of iron, with a little
S, and sometimes Ni and Co. No analy-
sis of a British specimen is known to the
author, but foreign specimens yield about
30 '0 per cent, of iron and 70 "0 per cent,
of arsenic. With iron = 32 '6 and arse-
nic 73'5 the formula will be FeAs2.
Loc. East Pool, Dolcoath, and pro-
bably many other Cornish mines. It
occurs largely in Norway and Germany.
Obs. It has been usually mistaken
for mispickel, from which it may be
distinguished by its small proportion of
of sulphur and its greater sp. gr. It not
unfrequently contains paying quantities
of gold and silver.
LIBETHENITE.
[Phosphate of Copper.] Rhombic ;
mostly in small crystals, like Fig. 139 ;
also globular, reniform, radiated, or com-
pact masses ; brittle ; fracture conchoi-
dal or uneven ; translucent on thin edges ;
lustre somewhat resinous ; olive or black-
ish-green ; streak olive-green ; H. 4 ;
G. 3-6-3-8.
B., etc. In matrass gives off water,
turns black, and often decrepitates ; on
C fuses to a dark globule of metallic ap-
pearance ; in R F with soda yields a bead
of copper, sometimes a slight alliaceous
odour; soluble in HC1 or ammonia,
still more readily in HNO3, forming a
blue solution ; decomposed by KHO, the
solution when neutralized with HNO3
yields a pale yellow ppt. on addition of
solution of nitrate of silver.
LIME URANITE.
LIMONITE.
63
Comp. Hydrated phosphate of cop-
per. Specimens from Libethen, in Hun-
gary, yield about 66 '5 per cent, of oxide
of copper, 29 '7 per cent, of phosphoric
anhydride, and 3 '8 per cent, of water.
With these proportions the formula may
be written Cu3P24-CuH2 or 3CuO, P2O5
+ CuH2Oo or P2O.2Cuo"a + CuHo2.
Loc. Gunnislake, Callington, form-
erly, with gozzan, qiiartz, and pyrites ; it
was also found at South Huel Frances
and some of the Gwennap mines (?), by
the late Mr. John Garby. Its chief
foreign localities are Hungary, Germany,
the Ural, South America, &c
Obs. This species is isomorphous with
Olivenite, and the phosphoric anhydride
is often partially replaced by arsenic an-
hydride.
Angles.
M M' = 92° 20' s e = 149° 06'
Ms 135 53 ee' 70 08
s s' 120 56
Lime Uranite. See Autunite.
LIMONITE.
[Brown Hematite. Hydrous Oxide of
Iron, &c.) Amorphous ; maramilated,
botryoidal, reniform ; fibrous, radiating,
or concentric ; compact, earthy, or fria-
ble ; stalactitic, &c. ; brittle ; fracture
conchoidal, uneven, or earthy ; opaque ;
lustre sub-metallic, resinous, silky, or
dull; brown, to yellowish or black;
streak yellowish -bro wn ; H. 5-5 '5, except
ochre and umber, which are often less
thanl; G. 3 '4-4.
Far. a. Brown Hematite is a reni-
form variety, with sub-metallic or silky
lustre, and concentric fibrous structure.
It is sometimes called Kidney Iron.
b. "Wood Hematite has bands of yellow
and brown alternately.
c. Stilpnosiderite is a black or very
dark brown variety, with conchoidal
fracture and splendant lustre.
d. Bog Iron Ore, Meadow Iron Ore,
or Ochrey Brown Iron Ore, is a soft
variety, often found in swampy places
in mining districts.
e. Yellow Ochre is a yellowish, earthy,
or friable variety.
f . Brown Umber is an impure, friable,
brown-coloured variety.
B., etc. In matrass gives off water
and turns darker ; on C infusible, turns
dark, and magnetic ; very thin splinters
may sometimes be melted with great
difficulty ; with borax and micro, gives
iron reactions ; soluble in warm HC1,
forming a yellowish solution ; of ten leaves
a portion of silica undissolved.
Comp. Hydrated peroxide of iron.
Of the following analyses a. is of a Corn-
ish specimen, by Yorke; b. and c. are
recent analyses of massive specimens
from Perran ; d. is a rusty -yellow stalac-
titic specimen from Botallack, by Prof.
A. H. Church (Journ. Chem. Soc., II.,
iii., 214):- t ^
a. b. c. d.
Peroxide of iron 8216 58 '77 75 '04 7373
Oxide of manga-
nese — 3-08 2-65 —
Alumina — 0'69 0'42 —
Lime — 6-39 Oil —
Magnesia — 0'26 012 —
Phosphoric an-
hydride 113 6-99 1-54 —
Silica 2-42 8'01 718 —
Water 14'28 14'87 12'02 24'40
Total 98-99 99'06 99'08 9813
This last specimen is considered to be a
distinct species by Dana, on account of
the large proportion of water. With
811 per cent, of peroxide of iron, and
18 '9 per cent, of water the formula might
be written Fe?2H2 or Fe2O3+2H2O or
Fe2OHo4. With peroxide of iron =
85 '6 per cent., and water 14 '4 it may be
written 2Fe2O3 + 3H2O or Fe4O3Ho6.
Loc. Botallack, and the St. Just
mines generally, in most of the
varieties ; Huel Mary, and other mines
in Lelant ; St. Ives Consols ; Great
Work; Huel Rose, Sithney ; Constan-
tino; St. Keverne; Trumpet Consols,
and other mines in Wendron ; Huel Her-
land ; Carn Brea ; Tincroft (Stilpnoside-
rite and other forms); Camborne Vean ;
Ting Tang, Huel Fortune, and other
Gwennap mines ; North Downs ; Huel
To wan, South Huel To wan, and several
other St. Agnes mines ; Perranzabuloe ;
Ladock ; Charlestown United, Ruby and
Knightor, and other mines near St. Aus-
tell, in several forms; Huel Maudlin
(Stilpnosiderite and other varieties);
Restormel Royal Iron Mines; Retire,
Withiel, and other places in Cornwall ;
Five Acre, Huel Prosper, Parkins, Sharp-
ham, Torbay, and other iron mines near
Brixham; Gymton, near Paignton;
Smallacombe and Hatherly, Ilsington;
Shaugh, and other places near Plympton ;
Combemartin (umber, yellow ochre, &c.);
Buckf astleigh ; Huel Robert, Sampf ord
Spiney ; Huel Betsey, near Tavistock ;
Copper Hill Mine, near Okehampton ;
on Exmoor ; East Down and Viveham,
near Barnstaple ; Buckland Brewer, near
Bideford ; Ugbrook Park, near Chud-
leigh (umber); and many other places in
the two counties.
64
LINAEITE.
LONCHIDITE.
Bog Iron Ore — Marazion ; Perran Con-
sols, in 1839, light yellowish-brown to
black ; " The light yellow ore appears to
have formed around, and enclosed, some
of the roots of the heath." (W. M.
Tweedy, Rep. Roy. Inst. Corn., 1839.)
Obs. It occurs in small quantities in
almost every metalliferous mine in the
world, except those worked in quartz
rock.
LINAEITE.
[Cupreous Sulphate of Lead.] Oblique,
with one perfect cleavage ; brittle ; frac-
ture conchoidal ; translucent ; lustre
vitreous to adamantine ; deep azure blue ;
streak pale blue; H. 2 '5-3; G. 5 '3-5 '45.
B., etc. In matrass gives off water
with acid reaction, and loses colour ; on
C fuses to a pearly globule ; in RF is
easily reduced to a malleable bead, de-
positing a yellow coating on the char-
coal, and yielding sulphureous odours;
with borax, alternately RF and OF,
yields a grain of copper ; decomposed by
HN03, leaving a white residue of sulphate
of lead, and forming a bluish solution.
Comp. The hydrated sulphate of lead
with copper specimens from Leadhills
yielded to Thomson and Brook nearly
757 of oxide of lead, 19 '8 of oxide of
copper, and 4 '5 of water. The formula
may therefore be written PbS + CuH2 or
PbSO4+CuH2O2 or SO2Pbo" + CuHo2.
LOG. Very small specimens were found
by Dr. C. Le Neve Foster at Huel Pen-
rose, Sithney, about the year 1866. It
occurs also in Cumberland, and at Lead-
hills, in Lanarkshire.
Obs. The crystals from Cumberland
are not much unlike Figs. 148, 149, 151.
The Cornish specimens were not crystal-
lized distinctly.
LIROCONITE.
[Octahedral Arseniate of Copper. Len-
ticular Arseniate, &c.] Rhombic or
oblique ; in obtuse faintly striated double
pyramids, like Fig. 165 ; crystals usually
minute, but have been obtained formerly
as much as one inch in length ; some-
times in granular masses, but more
rarely so than crystallized ; sectile ;
fracture conchoidal or uneven ; trans-
lucent ; vitreous to resinous ; sky-blue
to verdigris-green ; streak pale blue ; H.
2-2-5; G. 2-8-3-0.
B.t etc. In matrass gives off much
water and turns dark green ; on C alone
deflagrates (?), fuses readily to a dark
slag containing granules of copper; de-
posits a white incrustation on the char-
coal at a considerable distance from the
assay ; with soda, after well roasting,
yields a malleable bead of copper ; easily
soluble in HNO3 ; decomposed when in
powder by solution of KHO, leaving a
black powder of oxide of copper.
Comp. Hydrated arseniate of copper.
Of the following analyses of Cornish spe-
cimens a. was by Wachtmeister, b. by
Hermann, c. and d. by Damour : —
Oxide of copper 3773 36:38 3718 37:40
Alumina 8 '61 10 '85 9 '68 10 '09
Peroxide of iron 3 '66 0'98 — —
Arsenic anhy-
dride 22-29 23-0522-2223-40
Phosphoric an-
hydride 3-87 3-73 3-49 3 '24
Water 23 "84 25 '01 25 '49 25 '44
Total 100-00 100-00 98-06 99*57
The sp. gr. of b. was 2 '985, of d. 2 '964.
With oxide of copper 36 "61, alumina
11 '87, arsenic anhydride 26 "59, and water
24*93, the formula might be written
8Cu2As2Al2 + 24H2 or (CuO)3As2O5 +
Al2O3As2O5 + 5CuHoO2 + 19H2O or 2As2
O2Cuo"3 + AlaHo6 + 2CuHo2 + 19OH2.
Loc. Huel Muttrell, Huel Gorland,
Huel Unity, Gwennap, many years
since ; Great Hewas United, and Gun-
nislake more recently, but not such fine
specimens. It is also said to have oc-
curred at Huel Providence, Lelant.
Obs. It occurred always associated
with other arseniates of copper. Its
beautiful colour is sufficient to distin-
guish it from them all.
Angles.
MM' = 119° 20' oo = 107° 38'
Lithia Mica. See Lepidolite and Lepi-
domelane.
Lithomarge. See Kaolin.
Loadstone. See Magnetite.
Localities. A complete list of Cornish
and Devon localities, topographically
arranged, will be found in Part I. of this
book. In the case of minerals indicated
with type as follows : FLUOR or
JASPER, only the localities of the best
specimens, or those remarkable for their
situation, will be given ; in other cases
the author has given all the localities
known to him.
Foreign localities are indicated, with
the greatest conciseness, so as to shew
the wide distribution of many minerals
which are commonly supposed to be
almost exclusively Cornish. Of this,
Cassiterite is a noteworthy example.
Lonchidite. A peculiar variety of
marcasite which formerly occurred at
Cook's Kitchen and Tincroft mines, in
crystals resembling Fig. 152.
LUNNITE.
MAGNESITE.
65
LUNNITE.
[Phospliorocalcite. Pseudomalachlte.
Ehlite.] Oblique (?) or Khombic? reni-
form ; massive ; fibrous ; surface drusy ;
brittle ; fracture small conckoidal or un-
even ; translucent or sub-translucent ;
lustre adamantine or vitreous ; dark
green ; streak light green ; H. 4 '5-5 ; G.
4-4 '4.
B., etc. Like Libethenite.
Comp. Hydrated phosphate of cop-
per. The following is an analysis by
Heddle ; the sp. gr. of the specimen was
4'25 :—
Phosphoric anhydride 22 '73
Oxide of copper 6813
Water 8'51
Silica 0'48
Total 99-85
LOG. " Only one specimen of this
substance has hitherto been found in
Great Britain ; it is from Cornwall, and
in Mr. Greg's collection. Colour verdi-
gris-green ; translucent by transmitted
light. Consists of minute globular con-
cretions, not very closely compacted."
(Greg and Lettsom, Manual of Miner-
alogy, p. 324.) Foreign specimens have
occurred in Germany, Hungary, and
Siberia. Fig. 167 represents a foreign
specimen.
Angles.
O e = 146° 18' f f = 117° 49'
ge 168 46
Lustre. The reflection of light from
the surface of a body occasions what is
called its "lustre." The following are
the chief varieties observable in
minerals : —
a. METALLIC. Ex. Pyrites, Galena.
b. ADAMANTINE. Ex. Diamond.
c. VITREOUS. Ex. Crystallized Quartz.
d. RESINOUS. Ex. Some varieties of
Cassiterite.
e. PEARLY. Ex. Pearl Spar.
f. WAXY. Ex. Kerargyrite.
g. SILKY. Ex. Fibrous Carbonate of
Iron.
Each of these kinds of lustre may exist
in several degrees: as "splendant,"
"brilliant," "shining," "glimmering."
When no lustre is observable the speci-
men is "dull." The various kinds of
lustre are also qualified by the prefix
"sub." Thus many varieties of dark
mica have a "sub-metallic " lustre.
The true metallic lustre is only ob-
servable in minerals which are perfectly
opaque. The silky lustre is usually ob-
servable in minerals which have a fibrous
structure; while the pearly lustre is
j often seen in minerals having a foliated
or lamellar structure, and usually occurs
on the cleavage planes.
M.
Made. Twin Crystals, " Macles," or
"Hemitropes" are groups of two or
more crystals, which appear as if mu-
tually intersecting each other, or as if a
single crystal had been cut in two, one
part turned round a certain number of
degrees, and then re-united to the other.
Thus, if the octahedron Fig. 54 a., Plate
III. , be cut in two in the direction of the
dotted line, the one-half rotated 90°,
and then re-united to the other, a made
like Fig. 54 b. will be the result, as in
many crystals of Spinel, Alum, and
other minerals. Of course, such a divi-
sion and re-union has not really taken
place ; the whole crystal has pi'obably
taken the peculiar form from its first
formation. The corresponding axes of
macles are always inclined to each other,
in accordance with very precise laws.
Made. See Andalusite (Chiastolite).
Macro-diagonal. The greater of the
lateral axes in the rhombic system, also
a plane parallel to this axis and the
principal.
MAGNESITE.
[Carbonate of Magnesia.] Hexagonal;
in rhombohedrons ; with perfect rhom-
bohedral cleavages, forming angles of
72° 31' ; also massive ; compact, reni-
foim, earthy ; tough or friable ; fracture
conchoidal or earthy ; transparent to
opaque ; lustre vitreous ; shining to dull ;
colourless, white, yellow, brown, or
black ; streak lighter than colour ; H.
4 '5-5, except earthy varieties ; G.2-8-3'l.
ft., etc. In matrass no change, or loses
colour ; on C infusible, loses colour,
becomes alkaline; turns reddish with
Co ; soluble with effervescence in HC1,
HN03, or H2S04.
Comp. Anhydrous carbonate of mag-
nesia. Pure specimens contain — Car-
bonic anhydride 51'62 per cent., mag-
nesia 48 "38. With this composition the
formula may be written MgC or MgCO3
or COMgo".
LOG. From veins of serpentine in the
Lizard district (impiu-e). "An amor-
phous mineral of snowy whiteness, and
occasionally pulverulent, from West
Grambler, has been pronounced to be
carbonate of magnesia, but hitherto this
fact has not been confirmed." (J. Garby,.
66
MAGNETISM.
MALACHITE.
Trans. Hoy. Geol. Soc. Corn., VII., 81.)
Found also in Norway, Germany,
India, &c.
06s. It usually occurs in serpentine
districts. It may be distinguished from
calcite by its solubility in H2SO4, and by
its behaviour when treated with Co.
Magnetic Iron Ore. See Magnetite.
Magnetism. A property possessed by
many minerals containing iron, and in a
less degree by those containing Ni and
Co, especially after heating on C.
MAGNETITE.
[Magnetic Iron Ore. Oxidulated Iron.]
Cubic ; usually in modified octahedrons
or rhombic dodecahedrons, &c. (Figs. 1,
2, 3, 8, 10, 14, 15, 29, &c.); often macled ;
also compact, granular, lamellar, disse-
minated, or earthy ; brittle ; uneven or
conchoidal ; opaque ; lustre metallic or
sub-metallic ; splendant to dull ; iron-
black or dark brown ; streak like colour ;
H. 5 '5-6; G. 4-9-5-2; magnetic, espe-
cially when massive.
B., etc. In matrass no change, or
turns red ; on C infusible, or fuses with
very great difficulty, and often loses its
magnetism somewhat ; with borax gives
Fe reactions ; soluble in warm HC1 or
HN03.
Comp. Anhydrous proto-peroxide of
iron. A pure specimen contains of prot-
oxide of iron 35 '03, peroxide of iron
68-97, or iron 72 '41, oxygen 27 '59. With
this composition the formula may be
written FeFe.2 or Fe3O4 or Fe2O2Feo".
LOG. Botallack, Crown's Rock, and the
cliffs near by, massive, in bands or veins,
with garnets, hornblende, axinite, epi-
dote, and other rare minerals, also
as a black magnetic sand ; St. Michael's
Mount ; the Lizard, in hornblende ;
Gvvinter, in diallage rock ; Trelus-
well, near Penryn, with green chlo-
rite ; Tresavean, massive, in chlorite ;
near Redruth, crystallized ; Huel Jane,
Kea ; St. Agnes, in slate ; Huel Maud-
lin ; Lanlivery, with pyrites and garnet ;
Roche ; Fowey Consols, with chalcopy-
rite and francolite ; St. Stephens ;
Buckland-in-the-Moor, near Ashburton ;
Haytor, with hornblende and felspar ;
Hatherby, near Ilsington ; South Brent ;
near Tavistock ; in veins at Lundy
Island, &c. ; found also in Scotland, Ice-
land, Norway, and many foreign locali-
ties, in large quantities.
Obs. Massive magnetite may be dis-
tinguished from hematite by its black
streak ; crystallized specimens may be
distinguished by form alone.
Angles. The same as in Cuprite.
oo = 109° 28' dd = 120° 0(K
a a 90 00 &c.
MALACHITE.
[Green Carbonate of Copper.] Oblique ;
crystals minute, and like" Figs. 155, 156,
157 ; perfect cleavage parallel to M ;
usually massive, globular, reniform, bo-
tryoidal, mammillated, stalactitic; com-
pact, fibrous, or earthy ; brittle ; frac-
ture sub-conchoidal or uneven ; translu-
cent to opaque ; lustre adamantine or
vitreous ; often dull ; various shades of
green ; crystals dark green ; globular
! masses usually banded in concentric
: layers of different shades ; streak light
green; H. 3 "5-4; G. 3 '7-4.
-B., etc In matrass gives off water
• and turns black ; often decrepitates ; on
I C infusible and turns black ; in RF
! yields a globule of Cu ; more readily
| on addition of soda ; with borax yields
Cu reactions ; soluble with effervescence
in HC1 or HNO3 (dilute), forming a
i blue solution ; slowly turns ammonia
I blue.
Comp. Hydrated carbonate of copper.
! Pure specimens yield nearly 71 '91 per
cent, of oxide of copper, 19 '90 per cent.
of carbonic anhydride, and 8 19 per cent.
of water. With these proportions the
formula may be written CuC 4- CuH2 or
CttCOg+CuHjO, or COCuo" + CuHo2.
Loc. Botallack, Huel Cock, Huel
Edward, Huel Speed, and other mines
in St. Just ; Huel Alfred, Phillack ; St.
Michael's Mount, in small specks; West
Godolphin, Breage ; Mullion ; various
parts of the Lizard district, with native
copper ; Dolcoath and other Camborne
mines ; Huel Buller. Huel Basset, South
Huel Basset, and other mines near Red-
ruth ; Huel Gorland, Ting Tang, Car-
harrack, and many other mines in Gwen-
nap ; Huel Husband ; West Huel Vir-
g'n; Huel Music; Huel Mexico: Hewas;
uel Harmony ; Lanescot ; Pentire,
in acicular crystals ; Phoenix ; Gunnis-
lake ; Buckfastleigh ; Hennock, near
Chudleigh ; ComKemartiu, and other
places in Devon, in small quantities.
Obs. Malachite occurs in small quan-
tities in the older workings of almost
all the copper mines of the two coun-
ties. The crystals are usually found
lining cavities in the massive specimens.
It maybe distinguished from chrysocolla
by its superior sp. gr., hardness, and
abundant effervescence, and ready
solution when treated with dilute
HC1.
MALLEABLE.
MATEASS.
67
Angles.
M M' = 123° 35' M e = 112° 33'
OM 90 00 ee 107 16
OT 90 00
Malleable. Capable of being beaten
into thin plates. Ex. Gold, Silver,
Copper.
Malleable Copper. See Native Copper.
Mammillary. See Form of Minerals.
Manganese Spar. See Rhodonite.
MANGANITE.
[Grey Oxide of Manganese.] Rhom-
bic ; in prisms vertically and deeply
striated (Fig. 110); often grouped in
bundles, with perfect brachy diagonal
cleavage ; also massive, fibrous, radiat-
ing, compact, granular ; brittle ; fracture
uneven ; translucent on thin edges to
opaque; metallic or sub-metallic, often
splendant ; dark steel-grey to iron-black ;
streak brown or black ; H. 3 '5-4 ; G.
4 '2-4 '4 ; perfectly conducts electricity.
B., etc. In matrass gives off H2O ; on
C is infusible ; with soda, borax, and
micro, gives Mn reactions ; soluble in
warm HC1.
Comp. Hydrated manganic peroxide.
Pure specimens yield 89 '90 per cent, of
peroxide of manganese, and 10*10 per
cent, of water. With this composition
the formula will be Mn2H2 or Mn2O3H2O
or MngOsHog.
LOG Botallack, in brilliant crystals ;
Huel Bucketts ; Veryan ; Indian Queens,
near St. Columb ; Trebartha ; St. Min-
ver, well crystallized ; Lettcott ; Lanli-
very; Restormel (acicular); Upton Pyne,
near Exeter (well crystallized); Doddis-
combleigh, near Chudleigh ; in North
Devon ; in West Devon, in sandstone.
The mineral occurs well crystallized in
Scotland, Ireland, and in many foreign
parts.
06-5. It may be readily distinguished
from Pyrolusite by its lustre and hard-
ness ; from the ores of copper and anti-
mony by its inf usibility.
Angles.
M M' = 99° 40' k k = 103° 24'
MO 90 00
MARCASITE.
[White Iron Pyrites.] Rhombic; in
modified prisms (Figs. 150, 151, 152, &c.);
often macled; crystals usually striated,
sometimes rough ; often stalactitic, bo-
tryoidal, reniform, radiating ; brittle ;
fracture uneven ; opaque ; lustre metal-
lic, splendant to dull; pale yellow,
greenish, greyish, often a brown tarnish ;
streak dark greenish-grey j H. 6-6 '5 ; G.
4-6-4-9,
Far. a. Cocks-comb Pyrites is a macled
variety, which occurs in forms resem-
bling Fig. 152.
b. Lonchidite is a similar variety, con-
taining a little (2 to 6 per cent.) arsenic.
It is tin-white, greyish, or greenish -grey.
c. Hepatic Pyrites is a partly decom-
posed variety, of liver-brown colour.
B. , etc. In matrass gives a deposit of
S ; on C melts readily to a dark magne-
tic bead, gives off a sulphureous odour ;
insoluble in HC1; soluble in strong
HNO3, leaving a deposit of S.
Comp. Anhydrous sulphide of iron.
The following analysis of a specimen of
Lonchidite from Cook's Kitchen is by
Platnner : —
Sulphur 4961
Iron 44-23
Arsenic 4'40
Cobalt 0-35
Copper 075
Lead 0-20
Total 99-54
With iron 46 '67 per cent., sulphur 53 '33,
or the same as ordinary iron pyrites,
the formula may be FeS2.
Loc. Cook's Kitchen and Tincroft
(Lonchidite), on brown iron ore and py-
rites ; Huel Unity ; Creegbrawse ; Huel
Clifford ; Huel Rose, Newlyn ; Fowey
Consols ; Huel Crowndale ; Huel Cre-
bor (Lonchidite, in at tie heaps); Vir-
tuous Lady Mine, aggregated crystals,
very large, on quartz ; Combemartin ;
Tamar Mines, near Beerferris (formerly
in hexagonal prisms, pseudo after cal-
cite); found also in Cumberland, Scot-
land, Ireland, and many foreign locali-
ties.
Obs. It is best distinguished from
Pyrites by its crystalline form, paler
colour, and greater liability to sponta-
neous decomposition.
Margarodite. See Gilbertite.
Marmolite. See Serpentine.
Martial Arseniate of Copper. See
Scorodite.
Martial Pyrites. See Pyrites.
Massive. Regular structure, but no
distinct external form.
Matrass. A small vessel of glass with
a bulb blown at one end ; a bolt head ;
a simple tube closed at one end, used in
the testing of minerals by the aid of
heat. Two such tubes may be made
from a piece of glass tube about four
inches long and one-sixth wide, by
softening the centre in a gas flame or
candle flame, with the aid of a blowpipe,
and then pulling the ends asunder. For
the method of using such tubes sea
Blowpipe Reactions.
68
MEAGEE.
MESSOLITE.
Meagre. Minerals which feel soft and
rough are so called ; the word is used in
centra-distinction to harsh (hard and
rough) and unctuous (soft and smooth).
MELACONITE.
[Black Copper Ore.] Amorphous ?
cubic ? oblique ? usually massive, pul-
verulent, earthy, or investing ; friable ;
opaque ; dull ; dark grey to black ; streak
black and shining, or dull ; soils the
fingers ; H. below 1'5(?) G. 5 '2.
Var. "Melaconite crystals from Corn-
wall, collected by Mr. Tailing, have been
described by Maskelyne as 'monoclinic,'
' basal cleavage easy,' . .
'often twins,' . . 'H. a little above
4; G. 5-825-827; Church has ascertained
that the crystals are essentially pure
CuO.' It would appear . . that this
oxide of copper is trimorphous." (Dana,
Syst. Min., 1868.)
B., etc. In matrass usually gives off
some water ; on C is reduced to mallea-
ble copper where it touches the support ;
pure specimens are easily reduced to a
bead ; with borax or micro, gives Cu re-
actions ; with soda an indication of Mn is
often obtained ; soluble in HC1 or HNO3,
forming a green solution ; slowly soluble
io ammonia, forming a deep blue solution.
Comp. Anhydrous oxide of copper,
often containing silica, manganese, and
a little water. Pure specimens contain
copper 79 '85 per cent., oxygen 2015 per
cent. With these proportions the for-
• of 97° 39' and 82° 21' , with perfect basal
cleavage ; usually botryoidal, reniform,
stalactitic, pulverulent, incrusting, or
massive ; brittle; conchoiflal or uneven;
! translucent to opaque ; vitreous ; various
j shades of green, with a yellow or brown
! tarnish ; streak white ; H. 2 ; G. 1'8-
' 1'9 ; taste metallic and inky.
B., etc. In matrass fuses, swells up,
and gives off water, which reddens blue
litmus paper, leaving a yellowish infusi-
ble residue ; on C the same ; gives off
| SO.2 ; finally turns red and magnetic ;
with borax gives Fe reactions ; soluble in
H2O, forming a pale green solution, which
gives a rust-coloured precipitate with
ammonia.
Comp. Hydrated sulphate of iron.
Pure specimens yield 2719 percent, of
i oxide of iron, 31 '02 percent, of sulphuric
| anhydride, and 41 '79 per cent, of water.
j With these proportions the formula may
| be written FeS-f 7H2 or FeSO4 + 7H2O
| or SO2Feo"-t-7OH2.
Loc. Huel Prosper, in irregular nodu-
| lar or semi-crystalline masses ; St. Agnes ;
! Ting Tang ; United Mines ; Fowey Con-
| sols, Huel Maudlin ; and the old work-
' ings of many other mines in Cornwall, in
! small quantities. Found also in similar
circumstances in most mining districts.
Obs. It is probably produced by the
decomposition of pyrites or marcasite.
Distinct and well-formed crystals seldom
occur in nature.
Menaccanite. See Ilmenite.
mula will be Cu or CuO.
Loc. Botallack, Huel Speed, and
other St. Just mines ; Huel Trenwith ;
Huel Providence ; Marazion Mines ; West
Godolphin ; Great Huel Vor ; Great !
Huel Fortune; Huel Herland ; Relis-
tian ; Tresavean ; Ting Tang ; Huel J
Jewell ; United Mines ; Huel Basset ; I
Huel Buller ; Huel Trefusis ; Dolcoath ;
Tincrof t ; Huel Seton ; Great St. George, <
Perranzabuloe ; Pembroke ; East Crin-
nis ; Fowey Consols; Gunnislake; and
in small quantities in most of the copper
mines of the two counties, with other
ores of copper, of which it is, perhaps,
a decomposition product. It occurs in
copper mines and gozzans, under similar
circumstances, all over the world.
Obs. It may be easily distinguished
from wad, asbolane, and pyrolusite by
its yielding a bead of copper on C before
the blowpipe. From pitchblende by the
same reaction, and by its softness.
MELANTERITE.
[Copperas. Green Vitriol. Sulphate of
Iron.] Oblique ; in prisms, with angles
MESOLITE.
[Harringtonite. Antrimolite. Mealy
Zeolite.] Anorthic (?); two perfect cleav-
ages — 88° and 92° ; in acicjAar aggrega-
tions, the crystals always inacled ; in
divergent groups ordelicsrte tufts, lateral
planes being indistinct^ striated; also
massive, fibrous, columnar, drusy, com-
pact, porcellanous, &c., fragile; tough
when amorphous ; transparent to opaque ;
lustre vitreous or silky; white, colour-
less, greyish, yellowish; H. 3 '5-5 '5; G.
2-2-4.
Var. a. Antrimolite is a variety ; with
H. 3-5-4; G. 2-21.
b. Harringtonite has H. = 5 '25 ; G.
2-21 ; it occurs massive, earthy, and
tough.
B., etc. In matrass gives off much
water ; on C becomes opaque, if not so
already ; swells up into a vermicular
mass, and fuses to a blebby enamel; de-
composed by HC1, depositing gelatinous
silica.
Comp. Hydrated silicate of lime,
alumina, and soda. The composition of
METEORITE.
MIMETITE.
69
the Irish, Scottish, and foreign speci- |
mens hitherto analysed is from 45 '0 to
49'0 per cent, of silica, 25 '0 to 28'Oper ;
cent, of alumina, 5 '0 to 11 '0 per cent, of
lime, 4'0 to S'O per cent, of soda, and
10 '0 to 13 '0 per cent, of water.
Loc. The rocks between Botallack and
Huel Cock, with axinite and natrolite,
as a mealy deposit ; Stenna Gwynn. It ,
occurs also in Ireland, Scotland, Iceland,
and many foreign localities.
Obs. It is usually associated with vol-
canic rocks.
Meteorites. A meteorite of 231bs.
weight fell at Stretchley, in the parish
of Ermington, about 12 miles from Ply-
mouth, in the year 1623. (Trans. Devon.
Assoc. , vol. III. ) Another meteorite fell
at Menabilly, Cornwall, in 1791. (Greg
andLettsom, p. 246.)
Mica. This term, which was formerly |
applied to almost all minerals which
could be split into thin foliss, is now
made use of only as a convenient term
for a group of complex mineral silicates
having many properties in common.
a. They are all characterized by a per-
fect and easily obtained basal
cleavage ; so that they are readily
reduced to thin, tough laminae,
with usually a pearly or sub-
metallic lustre.
b. Potash is almost always present
among the protoxide bases, and
alumina among the peroxides.
c. The crystallization is either rhom-
bic or hexagonal, the angle formed
by any two adjacent prismatic faces
being 120°.
The Micas described in this Handbook
are —
Gilbertite, Lepidomelane,
Lepidolite, Muscovite.
Micaceous Iron Ore. See Hematite.
Micaceous Uranium Ore. See Autu-
nite and Torbernite.
Microcosmic Salt. This very useful
salt, a phosphate of soda and ammonia,
is largely used in the blowpipe examina-
tion of minerals. The colours of its beads,
formed with various metallic oxides,
are sometimes different to those pro-
duced with borax, and it affords a ready
means of detecting silica, which is solu-
ble in borax but not in " micro."
MILLERITE.
[Sulphuret of Nickel. Haarkies.] Hex-
agonal ; in six or twelve-sided capillary,
acicular, or divergent filaments ; brittle ;
opaque ; lustre metallic ; various shades
of yellow ; often a grey or iridescent tar-
nish ; streak like colour; H. 3-3 '5; G.
5-2-5-3.
B., etc. In matrass gives off SO2 and
a yellow sublimate ; on C fuses, boils,
forms a black magnetic mass ; with borax
gives Ni reactions ; insoluble in HC1 ;
soluble in warm HNO3 ; more readily in
Aqua Regia, forming a green solution.
Comp Anhydrous sulphide of nickel.
With nickel 64 '86 and sulphur 3514,
the formula may be written NiS. No
analysis of a British specimen is known
to the author.
Loc. Huel Sparnon, in capillary and
divergent fibres of a dull yellow colour;
Pengelley Mine, St. Ewe; Huel Chance;
Fowey Consols ; Combemartin, and near
Ilfracombe, in minute filaments lining
cavities, and dispersed among crystals of
galena. Found also in Wales, Scotland,
Ireland, Germany, &c., but everywhere
a rare mineral.
MIMETITE.
[Arseniate of Lead. Mimetesite. Kam-
pylite.] Hexagonal, in regular six-sided
prisms, often terminally modified (Figs.
188 and 190), or with curved faces ; also
fibrous ; mammillary ; sectile or brittle ;
imperfectly conchoidal or uneven ; trans-
lucent, resinous, or pearly ; yellowish,
greenish, often a brown tarnish ; streak
white, or nearly so; H 3 '5-4; G. 7 '0-7 '3.
Var. a. Kampylite, or Camphyllite,
is a yellowish-brown variety, which occurs
in crystals with convex faces (barrel-
shaped).
b. Hedyphane is a white variety.
H. , etc. In matrass gives a white sub-
limate ; on C fuses readily ; forms a
white incrustation, yields an arsenical
odour, and finally a bead of Pb with R
flame ; more readily on addition of soda ;
decomposed by strong HNOs, and by
KHO.
Comp. Anhydrous arseniate of lead,
with some chloride of lead. The follow-
ing analysis of a specimen from Huel
Unity was made by Mr. Gregor, in
1809:-
Arsenic anhydride 26 '40
Oxide of lead 69'76
Chlorine T58
Total 97-74
An analysis of a Cornish specimen by
Dufrenoy was equal to 84 '55 per cent, of
arseniate, 4 "5 per cent, of phosphate, and
9'05 of chloride of lead. With arseniate
of lead = 90-66 and chloride of lead 9 '34,
the formula might be PbCl2 + 3Pb3As2 or
SAsgO^Pbo's + PbClg. With arsenic an-
hydride 23-2, oxide of lead 67 '5, and
chloride of lead 9 '3 the formula might be
As303Pbo"4 ( Pb").
70
MINERAL.
MOLYBDENITE.
Lor,. Huel Unity, formerly, in very
fine thick light brown translucent crys-
tals, on galena, some more than three-
quarters of an inch long, also acicular ;
Huel Alfred, in the year 1824 fine crys-
tals of Mimetite were here first disco-
vered, in a cross lode ; "the crystals are
splendant, of a rich topaz colour;" "some
of the crystals § of an inch in length,
and J of an inch in diameter " 'Man. of
Min., Truro, 1825); Huel Gorland, fine
yellow crystals, on quartz ; Huel Rose
and Huel Penrose, Sithney ; Huel Pros-
per ; Penberthy Croft ; Huel Boys, En-
dellion ; North Downs Mine ; Beeral-
stone, with other ores of lead. Found
also in Cumberland, Durham, Yorkshire,
and most lead mining districts.
O6«. It usually has part of its arsenic
anhydride replaced by phosphoric anhy-
dride.
Mineral. Any natural, homogenous,
inorganic body. The word is used in
this sense throughout this Handbook.
Rocks are often composed of mixtures
of minerals, more or less impure. Ex.
Granite, The science which treats of
minerals may be conveniently sub-di-
vided into—
a. DETERMINATIVE MINERALOGY, in-
cluding the chemistry of minerals.
b. DESCRIPTIVE MINERALOGY, includ-
ing the sub-science of crystallo-
graphy.
c. SYSTEMATIC MINERALOGY, or the ar-
rangement of minerals into classes
and systems.
d. DISTRIBUTIVE MINERALOGY, or their
geographical distribution.
e. PARAGENETIC MINERALOGY, or their
mutual association in lodes and
rocks.
Mineral Pitch. See Bitumen.
MISPICKEL.
[Arsenical Iron. Arsenical Iron Py-
rites.] Rhombic ; in prisms or pyramids
(Figs. 90 to 93, &c. ) ; often striated, curved,
rough, or macled ; also acicular, or mas-
sive, columnar, radiated, fibrous; or dis-
seminated ; brittle ; fracture uneven ;
opaque ; lustre metallic, often glimmer-
ing only; tin- white to steel-grey;
streak blackish-grey ; H. 5*5-6; G. 6-6
.B., etc. In matrass a red sublimate;
on C fuses to a dark magnetic globule,
giving a yellow incrustation, and a sul-
phureous and arsenical odour ; soluble,
except the sulphur, in strong HNO^,
more readily in Aqua Regia.
Comp. Anhydrous sulpharsenide of
iron. With iron = 34 '37 per cent., sul-
phur 19 '64, and arsenic 45 '99 the for-
mulas FeS2 + FeAs2, FeSAs or Fe2S2Asa
may be used.
Loc. Botallack, Huel Castle, Levant,
and other St. Just mines ; Penzance hill ;
Wherry Mine ; Huel Mary and Provi-
dence, Lelant (containing silver); St.
Ives Consols ; West Poldice ; New
Rosewarne ; Huel Herland, Huel Unity,
Relistian, in chlorite, and other mines
in Gwiuear ; Huel Vor, Breage ; Carn
Camborne, Dolcoath, Cook's Kitchen,
Tincrof t, Carn Brea, East Pool, and other
mines in Camborne and Illogan ; Huel
Tolgus ; South Tolgus ; the United Mines ;
Huel Jewell ; Great He was United ;
Huel Maudlin ; Holmbush ; Devon Great
Consols ; Virtuous Lady (fine crystals,
imbedded in chlorite); Tamar Mines, near
Beerferris (fine crystals); Ivy Tor Mine,
near Okehampton ; and many other
localities in the two counties. It is a
very common mineral in many mining
districts in Cumberland, Scotland, and
abroad.
O6s. A large quantity of the white
arsenic of commerce is obtained from
this mineral, which is largely associated
with the tin and copper ores throughout
the district. A great deal of arsenic is,
however, in some mines obtained from
Leucopyrite.
A nrjles.
M M = 111° 22' r r' = 33° 32'
MO 90 00 e e 120 48
11' 100 38 si 159 50
s s' 62 08
Mock Lead. An old name for Blende.
Modified. Crystals which have small
planes in place of their solid angles or
edges are said to be modified ; thus Fig.
8 is an octahedron, modified by planes of
the cube ; Fig. 9 a cube, modified by
planes of the octahedron, &c.
MOLYBDENITE.
[Sulphuret of Molybdena. Molybdena
Glance.] Hexagonal; in small crystals
like Fig. 223, in irregular flat tables with
perfect basal cleavage ; foliated, mas-
sive, or scaly ; flexible, but not elastic ;
opaque ; lustre metallic ; colour like
freshly-cut lead ; streak greenish-grey ;
marks paper like plumbago ; unctuous ;
H. 1-1*5; G. 4-4-4-8.
-B., etc. In matrass unchanged ; on C
infusible, but gives off SO^ and burns
away, colouring the flame green, except
a small ash, which gives Mn or Fe reac-
tions with soda and borax; effervesces
when fused with soda ; insoluble in warm
HC1 or HNO3 ; soluble in strong H2SO4,
forming a blue solution.
Comp. Anhydrous sulphuret of mo-
lybdenum. Pure specimens yield 59 '13
MUNDIC.
NICCOLITE.
71
per cent, of molybdenum and 40 '87 per
cent, of sulphur, the formula being
MoS2.
Loc. Huel Mary, Lelant ; Huel Friend-
ship ; Huel Unity, and other mines in
Gwinear ; Huel Gorland, and other parts
of Gwennap, in elvan ; Menabilly ;
Drake walls Mine, Calstock. It is also
found in Cumberland, Scotland, and
many foreign localities. It has been
found in slags from copper smelting
works.
Obs. It may be distinguished from
graphite by its superior sp. gr., blowpipe
reactions, and the colour of its streak on
porcelain.
Mountain Cork, Mountain Paper,
Mountain Leather, Mountain "Wood.
See Amphibole.
Mundic. See Pyrites.
Murchisonite. See Orthoclase.
Muriate of Copper. See Atacamite.
Muriate of Silver. See Kerargyrite.
MUSCOVITE.
[Mica. Potash Mica.] Oblique (?); or
Hexagonal (?); sometimes occurs in
prisms, but more usually in tables like
Figs. 239 to 241, or irregularly-shaped
scales, or massive ; cleavage perfect and
easily obtained, basal ; thin plates flex-
ible and elastic ; tough ; lustre pearly or
sub-metallic ; white, grey, brown, yellow,
&c. ; often dichroic ; translucent ; thin
plates transparent; streak white or grey-
ish ; H. 2-3; G. 2-8-31.
/?., etc. In matrass unchanged, but
usually yields traces of HF ; on C some
varieties are readily fusible to an opaque
or glassy enamel : insoluble in HC1 or
H2S04.
Comp. A complex silicate of alumina,
iron, potash, &c.
Loc. St. Dennis, near St. Austell.
Probably most of the mica of the Cornish
and Devonshire granites belongs to this
species, but as crystals are rare it will
probably be necessary in any future close
examination of these micas to distinguish
them by their optical properties. The
chemical constitution of the micas seems
too varied to form the basis of a sub-
division, as least at present.
Art files.
M M' = 120° 46' o b = 90° 00'
MO 98 40 or 107 05
Mb 119 38 bx 148 30
That there is still some confusion as to
the species, is seen in the fact that, al-
though the above angles are given as
those of muscovite, Descloiseaux states
that its crystals are right rhombic prisms
of 120°, or just the same as Lepidolite
and Lepidomelane.
N.
Nacrite. See Gilbertite.
Nail-headed Copper Ore. See Chal-
cocite.
Native Arsenic and other metals. See
the metals.
Native Loadstone, Native Magnet.
See Magnetite.
NATROLITE.
[Needle Stone. Mesotype. Zeolith.]
Rhombic, in slender or acicular prisms,
like Figs. 112 and 113, with perfect lon-
gitudinal cleavages; also mammilated,
massive ; fibrous or radiating ; brittle ;
fracture conch oidal or uneven; trans-
parent or translucent, occasionally
opaque ; lustre vitreous or silky, pearly
on cleavage planes; white, yellowish,
greyish, greenish, or brown ; streak
white ; H. 5-5' 5; G. 2 '2-2 '3.
B., etc. In matrass gives off water;
on C fuses readily, often boiling ; colours
the tip of the flame yellow ; the white
residue treated with Co turns blue ; de-
composed readily by HC1 or oxalic acid,
depositing gelatinous silica.
Comp. Hydrated silicate of soda and
alumina. The Cornish specimens are not
known to have been analysed, but foreign
specimens yield about 48 '6 per cent, of
silica, 277 per cent, of alumina, 16 '6 per
cent, of soda, and 9 '7 per cent, of water.
With these proportions the formula may
be written Na2Si+Al22Si + 2H2 or Si3O2
Al2oviNao2 + 20H2.
Loc. The rocks between Botallack
and Huel Cock, and at Huel Carne, with
Prehnite and Stilbite. Said to have been
found also at Stenna Gwynn. It is also
found in Ireland, Scotland, and many
volcanic districts abroad.
Obs. It is one of the very rarest
British minerals.
Angles.
M M' = 91° 00' 00 = 143° 20>
MO 116 40
Needle Spar. See Aragonite.
Nephrite is said to have been found in
the Lizard district, but the specimens
were probably Saussurite.
NICCOLITE.
[Kupfernickel. Copper Nickel. Arse-
nical Nickel. ] Hexagonal ; usually mas-
sive and compact ; also reticulated, ar-
borescent, reniform, or columnar ; brit-
tle ; fracture uneven ; opaque ; lustre
metallic ; pale copper red, often with a
greyish or blackish tarnish ; streak pale
brownish -black ; H. 5-5 '5 ; G. 6 '6-7 '3.
72 NICKEL OCHEE.
OLIYENITE.
B., etc. In matrass gives a faint white
sublimate ; in open tube turns yellowish-
green, and yields a white crystalline
sublimate ; on C fuses easily to a glo-
bule, giving off strong arsenical odours ;
with borax yields reactions for Fe, Co,
Ni, &c. ; soluble in Aqua Kegia, forming
a green solution.
Comp. Anhydrous arsenide of nickel.
"With arsenic = 55 '98 per cent, and nic-
kel 44 '02 the formula might be written
NiAs.
Loc. Huel Chance, St. Austell, with
Millerite ; Fowey Consols, formerly, in
the 200 fathom level; Pengelly Mine,
St. Ewe, massive, and in tine fibres ;
Black Down, Devon, with Rhodonite and
Psilomelane. Found also in Scotland,
Germany, France, and many other
foreign localities.
Obs. It may be easily distinguished
from native copper, which it often some-
what resembles in colour, by its hard-
ness and brittleness.
Nickel Ochre. See Annabergite.
Noble Metals. Those metals the
oxides of which can be reduced by heat
alone, without the use of carbon or
fluxes. Ex. Gold, Silver, Mercury, Pla-
tinum.
Nodular. Occurring in nodules.
Nodule. An irregular rounded mass.
O.
Oblique Prismatic Arseniate of Copper.
See Clinoclase.
Ochre. See Hematite and Limonite.
Octahedral Arseniate of Copper. See
Lirocouite.
Octahedral Cobalt Pyrites. See Smal-
tite.
Octahedral Copper Ore. See Cuprite.
Octahedral Copper Pyrites. See Eru-
bescite.
Octahedral Iron Ore. See Magnetite.
Octahedron. A solid figure having
eight sides. In the regular octahedron
these are equal equilateral triangles
(Fig. 1).
Odour. A character of some value in
the discrimination of minerals in a few
instances. Thus, many substances con-
taining alumina give off a peculiar
" earthy " smell when breathed upon or
broken. Many ores containing sulphur
or arsenic give off peculiar odours when
broken or rubbed, aa is also the case
with some varieties of quartz, calcite,
barytes, &c.
OLIVENITE.
[Olive Copper Ore. Olive Malachite.
Right Prismatic Arseniate of Copper.
Pharmacochalcit.] Rhombic ; in prisms
variously modified (Figs. 136, 137, 138);
the planes often curved, striated, or
rough ; more usually reniform, stalac-
titic, fibrous, or capillary ; or massive,
| nodular, granular, or earthy ; brittle ;
I fracture conchoidal or uneven ; lustre
I adamantine, vitreous, resinous, or silky ;
shining to glimmering ; various shades
of greyish or brownish-green ; streak
like the colour, but lighter ; H. 3 ; G.
| 3-9-4.
Var. Wood arseniate is a fibrous con-
I centric variety, with but little lustre,
1 and often almost ash-coloured.
B., etc. In matrass gives off water
and turns darker ; on C fuses at 1 to a
i dark globule, which crystallizes on cool-
| ing ; sometimes deflagrates ; deposits
an abundant white inci'ustation on the
cool part of the charcoal support ; gives
off a strong arsenical odour ; with soda
yields a malleable bead of copper ; solu-
ble in HNO3, and partially so in ammo-
nia, forming a blue solution.
Comp. Hydrated arseniate of copper.
The following are analyses of Cornish
specimens, a. by Yon Kobell, a massive
specimen ; b. and c. by Richardson,
massive and acicular ; d. by Damour, sp.
gr. 4 '378; e. by Hermann, sp. gr.
4135 :—
a. b. c. d. e.
Arsenic anhy-
dride 36-71 39-9 39-80 34 "87 33 "50
Oxide copper 56 '43 56 "2 56 '65 56 "86 56 '38
Phosphoric
anhydride.. 3 -36 — — 3 '43 5 "96
Water 3'50 3'9 3'55 372 416
Total 100 -00 100 -0 100 "00 98 '88 100 "00
The following analyses perhaps point to
a different composition ; f . , a fibrous spe-
cimen, by Hermann, G. 3 '913; g., by
Thomson, fibrous ; h., by Klaproth: —
f. g. h-
Arsenic anhydride... 40 '50 40 '61 45 "00
Oxide of copper 51 '03 54 '98 50 '62
Phosphoric anhydride I'OO
Oxide of iron 3'64
Water .. . 3 '83 4 '41 3 "50
Total lOO'OO 100-00 9912
With arsenic anhydride 40'6 per cent.,
oxide of copper 56 "3 per cent., and water
31 per cent, the formula maybe written
4Cu, As2, H2 or Cu3As2O8 + CuH2O2 or
As2O2Cuo"3 + CuHo2.
Loc. Huel Unity, Huel Gorland, Ting
Tang, Carharrack, and other mines in
Gwennap (most varieties); Huel Buller;
OPAL.
OPTICAL CHARACTERS. 73
Pednandrea ; Tincrof t ; Beam Mine ;
Phoenix ; Gunnislake ; Bedford United
Mines, near Tavistock, in olive-green
prismatic crystals, also fibrous and acicu-
lar. It is found also in Cumberland, and
many foreign localities.
Obs. It will be seen that, as is fre-
quently the case with arseniates, a small
proportion of the arsenic anhydride is
replaced with phosphoric anhydride.
The massive varieties may be distin-
guished from other arseniates of copper
by their olive-green or ash-grey colour.
Crystals may be known by their forms.
Angles.
M M' = 92° 30' a b = 90° 00'
Mb 136 15 vb 125 46
Ma 133 45 ea 124 35
ee' 69 10
The combinations most frequently seen
are Me, Meb, Meba, Mebav. The
faces e and a are frequently uneven.
OPAL.
Amorphous ; massive, reniform, sta-
lactitic, &c. ; brittle ; fracture conchoidal,
even, or uneven; transparent to trans-
lucent on edges ; lustre vitreous, resi-
nous, or pearly ; colourless, milk-white,
grey, red, brown, blue, green ; often a
play of colours as the specimen is moved
about ; streak white; H. 5 "5-6 '5; G.
1-9-2-3.
Var. a. Common Opal is semi-trans-
parent, and the colours are dull.
b. Semi-opal is similar, but less trans-
parent, and with still duller colours.
c. Ferruginous Opal (Eisenkiesel or
Iron-flint) is a hignly ferruginous variety.
d. Wood-opal has the form and tex-
ture of wood, of which it is often a
silicified variety.
e. Hyalite or Muller's Glass is vitre-
ous, transparent, and colourless.
f. Fire-opal is transparent or semi-
transparent ; red or yellow, and irides-
cent.
g. Noble Opal is semi-transparent or
translucent, of a milk-white, bluish, or
yellowish-white colour, and exhibiting a
beautiful play of colours.
h. Cacholong is white and opaque.
i. Hydrophane is nearly opaque when
dry, but if immersed in water becomes
nearly transparent.
B., etc. In matrass usually yields
water ; on C infusible ; sometimes de-
crepitates, or turns red or opaque ; with
soda melts with much effervescence to an
opaque or transparent bead ; with micro,
retains its form and appearance ; inso-
luble in HC1, HNO3, H.2SO4, or Aqua
Regia ; the powder soluble in KHO.
Comp. Hydrated silica, with from
3'0 to 13 '0 per cent, of water, and varia-
ble quantities of alumina, lime, magne-
sia, potash, soda, or oxide of iron.
LOG. 1. Common Opal. — Botallack,
Huel Stennack, Huel London, Trewel-
lard, the Bunny, and Huel Spearn, St.
Just ; Huel Spinster, Huel Damsel, and
Huel Buller, near St. Day and Redruth;
North Roskear, Camborne ; Huel Rose-
warne, Gwinear ; Stenna Gwynn ; Huel
Sovereign, massive, blue and white, pre-
sented to Royal Institution of Cornwall
in 1846 ; Trugoe ; Huel Maudlin ; Hay
Tor ; on Dartmoor ; Lustleigh, &c.
2. Semi-opal occurs at most of the
above localities, and especially near Oke-
hampton, of a snow-white colour.
3. Wood-opal (silicified wood) occurs
on the Blackdown-hills, Devon.
4. Ferruginous Opal occurs especially
in the St. Just mines and near Cambome.
5. Fire Opal occurs, of a greyish-white
colour, at Botallack; Rosewarne; Huel
Spinster, and Huel Gorland (yellow),
St. Day.
6. Cacholong, of a cream colour, on
quartz and with steatite, from Botallack,
is now in the Museum of tho Royal In-
stitution of Cornwall.
065. Opal may be distinguished from
the different varieties of calcedony by
the larger quantity of water given off
when heated in a matrass, by its inferior
hardness and gravity, and by its solubi-
lity in caustic potash. It is, however,
possibly, only an extreme form of calce-
dony, which usually contains some water,
and is slightly soluble in caustic potash.
The finest opals come from Mexico.
Opalescent. Resembling opal in lustre
and texture ; exhibiting a play of colours
or iridescence, like fire-opal and noble
opal.
Opaque. Substances through which
light cannot pass are said to be opaque.
The minerals having true metallic lustre,
as Pyrites, Galena, &c., are the most
opaque.
Ophiolite, Ophite. See Serpentine.
Optical Characters of Minerals. The
chief of these are : —
1. Colour.
2. Lustre.
3. Diaphaneity.
4 , Phosphorescence.
5. Fluorescence.
6. Refractive power.
7. Polarization.
Each of these are described under
their respective heads.
74
OETHOCLASE.
OKTHOCLASE.
OR-THOCLASE.
[Felspar. Potash Felspar. Orthose ;
&c.] Oblique; in prisms, often flattened,
or variously modified (see Figs. 172 to
180); two perfect cleavages (basal and
clinodiagonal, M., O.), making angles of
90° 00' ; brittle ; fracture conchoidal, un-
even, or splintery ; transparent to nearly
opaque ; vitreous to pearly ; white, grey,
red, green, brown, or black ; streak
white, greyish, or slightly tinted like the
colour ; H. 6 ; G. 2 '5-2 '6.
Far. a. Adularia is colourless and
transparent ; sometimes a little green-
ish, opalescent, or a faint play of colours ;
cross fracture conchoidaL
b. Moonstone is like Adularia, but
contains bluish-white spots, which, when
held to the light, appear pearly or
silvery.
c. Murchisonite is a flesh-red variety,
pale or deep in tint ; viewed in an oblique
direction it has gold, yellow, or silvery
reflections on a third cleavage ; a micro-
scopic examination seems to indicate that
it is a compound of Orthoclase and
Albite.
d. Common Felspar. Colour very va-
rious, but often pink or reddish, and
usually a not very brilliant lustre.
e. Erythrite. A flesh-red variety, con-
taining 3 per cent, of magnesia.
f. Amazon Stone is a clear green cleav-
able variety.
g. Sanadin, or Ryacolite, occurs in
glassy transparent crystals, mostly tabu-
lar. It is often associated with modern
lavas or pumice.
h. Compact Felspar is an uncleavable
variety.
i. Pitchstone is, perhaps, an amor-
phous variety, of dark pitchy appearance.
B., etc. In matrass not changed, or
loses colour ; on C fuses at about 4 to a
blistered slag, or infusible ; with borax
dissolves slowly, with effervescence, to a
clear glass ; insoluble in micro.; insoluble
in HC1 and HNO>
Comp. Anhydrous silicate of potash
and alumina, with small quantities of
other bases. Of the following analyses
a. and b. are Orthoclase, from Trewavas
Head, Breage, by Professor Haughton,
recently (a. from veins at foot of cliff, b.
from granite at head of cliff); c. and d.
of Orthoclase from the "Glass Mine,"
Roche, by Phillips (Phil. Mag. Feb.,
1871); e. is an analysis of felspar from
Dartmoor ; f. of Murchisonite from Ex-
minster, both by Prof. Church (Rep. Dev.
Assoc., vol. II., p. 201); g. is Murchiso-
nite, from Dawlish, by Phillips (Phil.
Mag. vol. 1, 1814, p. 448).—
a b. c. d.
Water 0'40 0'40 0'83 0'50
Silica 63-60 63'20 65'00 65'33
Alumina 21 '04 21 '00 19 '00 19 '16
Ferric oxide ... trace trace '50 *50
Lime 0'90 0'68 T57 1'68
Magnesia - trace trace
Potash 9-91 10-30 10'37 10'37
Soda 3-08 2'75 2'40 2'40
Total 98-93 98 '33 99 '67 99 '94
e. f. g.
Silica 65-61 65'27 68'60
Alumina 1973 20'34 16'60
Potash 1273 12'43 14'80
Soda 1-50 1-44 —
Lime 0'33 0'33 —
Magnesia 010 019 —
Total 100-00 100-00 lOO'OO
With silica 69 '7 per cent., alumina 19 7
per cent., and potash 10 '6 the formula
may be written 6Si, K2, A12 or Al2O33Si
O2+K2OSiO2 + 2SiO2 or Si6O8Ko2Al2ovi.
This last is the formula given by Pro'fes-
sor Frankland. With silica 60 "5, alumina
25 "7, and potash 13 '7, the formula might
be 4Si, K2, A12 or Al2O33SiO2 + K2OSiO2
or Si4O4Ko2Al2oTi.
Loc. 1. Adularia — Tintagel and Dela-
bole, in slate ; Kit-hill, Callington ; said
to have been found also in prisms at
St. Just.
2. Moonstone is said to have been
found at Gluvias Burnt-house, near
Penryn.
3. Murchisonite — Heavitree, near Exe-
ter; Exminster; Topsham ; Jacobstowe ;
Crediton ; and near Dawlish, in the red
conglomerate ; the finest masses are ob-
tained on the coast between Teignmouth
and Dawlish, often lying on the beach.
4. Common Felspar — Fine crystals or
masses have been obtained at the Scilly
Isles ; Boscreagen Cove, near the Land's
End, of a deep red colour ; Pendeen
Cove, in fine crystals imbedded in schorl
rock ; Botallack, Balleswidden, and many
of the St. Just mines, in fine masses ;
Mulvra-hill, Sancreed ; Morvah United
Mines ; Ding Dong, Madron ; St. Ives
Consols ; Huel Mary, and other mines in
Lelant ; Lamorna Point, near Penzance ;
the Marazion Mines ; Huel Darlington ;
St. Michael's Mount ; Trewavas Head,
Tremearne, and Great Huel Fortune,
Breage, in granite ; Huel Ann, Trumpet
Consols, and many other mines in Wen-
dron ; Kynance ; near the Old Lizard
Head, in green talc ; Coverack Cove,
Huel Union, Towednack, and other
places in the Lizard district ; the United
ORTHODIAGONAL.
PENTLANDITE. 75
Mines, Tresavean, Huel Fortune, and
other mines in Gwennap ; East Huel
Crofty; Dolcoath ; East Pool; Huel
Coates, St. Agnes (in twin crystals, some
converted intoCassiterite); Cligga Head,
in a decomposing granite ; near Truro,
in beautiful pink crystals, in several
elvans ; St. Stephens, St. Austell Hill
Mine, and other localities near St. Aus-
tell ; Luxulyan ; and a large number of
other localities near the granite.
Birch Tor Mine ; North Bovey ; Hay
Tor ; Ivybridge, in altered Devonian slate,
with Chiastolite ; Bovey Tracey, in fine
red crystals ; Lundy Island, with rock
crystal ; and many other places.
5. Sanadin, or Glassy Felspar — Little
Haldon-hill, near Teignmouth, in large
Ttals imbedded in porphry.
Pitchstone— Skewes, Crowan ; Carn
Brea ; South Huel Basset.
Obs. Only the more remarkable loca-
lities of felspar are given above, or where
it is obtained in very pure specimens.
Felspar forms a large proportion of the
widely-spread masses of granite in Corn-
wall and Devon. The only certain way
to distinguish between massive ortho-
clase and albite is by analysis ; but good
indications may be obtained by observing
the cleavages, and also by the blowpipe
behaviour. See Albite.
Angles.
T T = 118° 54' O x = 129° 41'
TO 112 16 Oy 99 38
TM 120 36 Mn 134 57
Tn 95 14 Mz 150 35
Tx 110 40 Mo 116 53
Ty 134 19 oy 140 33
OM 90 00 oz 124 59
Orthodiagonal. That lateral axis which
is at right angles to the principal in the
eblique system ; also a plane parallel to
that axis and the principal. Thus, in
Figs. 168, 169, the plane a. is orthodia-
gonal ; in 170, 171, the plane T.
Oxide. A combination of an element
with oxygen is so called. Those oxides
which form acids by addition of water
are also called anhydrides by many
chemists.
Oxide of Antimony. See Yalentinite
and Senarmontite.
Oxide of Arsenic. See Arsenolite.
Oxide of Bismuth. See Bismite.
Oxide of Cobalt. See Asbolane.
Oxide of Copper. See Cuprite anc
Melaoonite .
Oxide of Iron. See Magnetite, Hema
tite, Limonite, and Goethite.
Oxide of Lead. See Plumbic Ochre.
Oxide of Manganese. See Pyrolusite
Manganite, Psilomelane, and Wad.
Oxide of Tin. See Cassiterite.
Oxide of Tungsten. See Wolframite.
Oxide of Uranium. See Pitchblende
and Zippaeite.
Oxidising Flame. See Instructions for
ihe Examination of Minerals before the
blowpipe in Part I., and "Blowpipe
Reactions," p. 18, Part II.
Oxychloride of Copper. See Ataca-
mite.
Oxydulated Iron. See Magnetite.
Oxygen Ratio. This is a terra, used to
express the rates between the proportion
if oxygen in base and acid in a compound
containing both. The modern unitary
;heories of chemistry have, therefore, in
some degree lessened the use of the ex-
pression ; since, by these, salts are not
.ooked upon as compounds of base and
acid. The oxygen ratio is most referred
;o in speaking of silicates, and was
formerly considered of great value in
determining their specific value. Pro-
fessor Dana, however, would seem to
consider it of but little importance, as
the following remarks shew: — "The fel-
spar group is remarkable for its unity in
crystallographic and all physical charac-
ters, evincing the profoundest isotypism,
and yet the O ratio for the bases of silica
varies from 1-1 to 1-3." (Syst. Min.,
1868.) See also p%ge 46, Part II. of this
Handbook, under Felspar.
P.
Parti-coloured. When the colour of a
mineral specimen is different in different
parts this term is often used.
Peacock Copper. See Chalcopyrite.
Peach. A Cornish name for Chlorite.
Pearl Spar. See Dolomite.
Pechurane. See Pitchblende.
PENTLANDITE.
[Eisennickelkies. Sulphuret of Iron
and Nickel.] Cubical, with octahedral
cleavage ; usually massive, granular, or
imbedded ; brittle ; fracture uneven ;
opaque ; lustre metallic ; light bronze
yellow or brownish; streak dark brown ;
H. 3'5-4; G. 4'6; not magnetic.
B., etc. In matrass gives a yellow-
sublimate ; in open tube a strong sul-
phureous odour; on C fuses to a dark
brittle bead; with borax and micro,
yields iron reactions. Soluble in HNO3,
forming a greenish-yellow solution.
Corny. Anhydrous sulphide of iron
and nickel. With iron 42 '0 per cent.,
sulphur 35 '9 per cent., and nickel 22 '1
per cent, (which is very near Scheerer's
analysis of a Norwegian specimen), the
formula may be written 2FeS + NiS.
76 PEEOXIDE OF IEON.
PHOSPHATES.
LOG. Huel Jane, near Truro, about
the year 1857, in large masses, associated
with Vivianite.
06?. Its general appearance, physical
characters, and blowpipe reactions are
not greatly different to those of Pyrrho-
tite (Magnetic Pyrites). It is not, how-
ever, magnetic like Pyrrhotite, and the
considerable proportion of nickel may be
easily detected by humid analysis.
Peroxide of Iron. See Hematite,
Limonite, Goethite.
Peroxide of Tin. See Cassiterite.
Petroleum. See Bitumen.
PHARMA COSIDERITE.
[Cube Ore. Arseniate of Iron.] Cubic;
in cubes usually modified (Figs. 2, 3, 9,
16, 49, 50), with some planes striated,
others curved, or rough ; rarelv massive ;
brittle ; fracture uneven or sub-conchoi-
dal ; translucent to opaque ; lustre vi-
treous, adamantine, or greasy ; various
shades of green, often tarnished yellow
or brown ; streak pale green, yellowish,
or brownish; H. 2 '5; G. 2 '9-3; pyro-
electric.
.B., etc. In matrass turns red, gives
off H2O and a whitish sublimate ; on C
fuses easily to a grey magnetic slag,
yielding a very strong alliaceous odour ;
with borax and micro, gives Fe reac-
tions ; soluble in HC1 or HNO3.
Comp. Hydrated arseniate of iron.
The following are analyses of Cornish
specimens of " arseniate of iron," a. and
b. by Chenevix, c. and d. by Berzelius : —
a. b. c. d.
Arsenic anhydride 31 '0 33 '0 38 '00 40 '20
Peroxide of iron ... 45 '5 27 '0 40 '56 39 '20
Oxide of copper... 9'0 22'5 0'60 0'65
Silica 4-0 3'0 0'35 176
Phosphoric anhy-
dride - - 0-70 2-53
Water... .. 10 "5 12 "0 19 "57 18 '61
Total 100-0 97'5 9978 102'95
With arsenic anhydride 41 '7 per cent.,
peroxide of iron 38 '1 per cent. , and water
19 '6 per cent., the formula may be writ-
ten 4Fe2, 3As2, 18H2 or 3(Fe2As.2O8 +
5H2O)+Fe2H66e or 3(As2O2Fe2ovi5OH2)
+ Fe2Ho6. These formulae agree* pretty
well with the analyses c. and d. , but not
with a. and b., which are, perhaps, seme
other mineral. As is usual, a part of
the arsenic is replaced by phosphorus.
Loc. Formerly at Huel Jane, near
Truro, in cubes, with the alternate
angles replaced, some with all the angles
and edges replaced ; Huel Falmouth ;
Huel Unity, Huel Gorland, and Carhar-
rack Mine Gwennap, with many ores of
copper (some inferior specimens have
lately been found on the burrows in this
neighbourhood); Carn Brea Mine, in dark
green or yellowish -green cubes ; Botal-
lack, Levant, and Huel Owles, St. Just,
in crystals which were usually covered
with a dark tarnish ; Beam Mine, in
rhombic dodecahedrons of a brilliant
grass-green, bottle-green, or pale blue
colour, the size of pins' heads (Man. of
Min., Truro, 1825, p. 63); recently at
Pednandrea, in fine green modified cubes.
Obs. This mineral is rarely found
other than crystallized, and the crystals
are usually very small, one-eighth of an
inch being considered a good size.
A ngles
a a = 90° 00'
dd 120 00
o o 109 28
ak 109 28
a d 135 00
ao = 125°
od 144
ok 164
k k 152
dk 160
16'
44
12
44
32
The forms 2, 3, 9, 16, 49, 50, are all
Cornish, most of them being in Mr.
Greg's collection.
Phosgenite. See Cromfordite.
Phosphates. Compounds of phospho-
ric anhydride with metallic oxides are so
called, or phosphoric acid in which the
hydrogen has been replaced by a metal.
Phosphates may often be detected by
the green tint which they impart to a
blowpipe flame, and especially if first
moistened with H2SO4 and heated in
OF. In the presence of copper and some
few other bases this reaction is obscured,
when very small quantities may be de-
tected by the following method : — The
material to be tested is finely powdered,
mixed with five times its volume of a
mixture of three parts carbonate of soda,
one of silica, and one of nitre, and the
whole fused on platinum foil. The fused
mass is dissolved in water and filtered ; to
the clear liquid a few drops of a solution
of carbonate of ammonia is added. The
solution is then boiled, and silica sepa-
rates as silicate of soda, which should
be filtered off. Acetic acid is then added
to the clear solution, slightly in excess,
it is then boiled to expel carbonic anhy-
dride, and a drop of solution of nitrate
of silver added. If a yellow precipitate
should fall after this treatment it is evi-
dence of phosphorus.
Most arseniates contain at least traces
of phosphoric anhydride. The phos-
phates found in the two counties are the
following : —
Apatite,
Pyromorphite,
Childrenite,
Vivianite,
Beraunite,
Libcthenite,
C/iurchite,
Lunnite,
Demidoffite,
Torbernite,
A utumte,
Wavellite.
PHOSPHATE OF CERIUM.
PINITE.
77
Of these, Apatite and Pyromorphite
are anhydrous ; the rest are hydrous.
In many of them traces of arsenic anhy-
dride may usually be detected.
Phosphate of Cerium. See Churchite.
Phosphate of Copper. See Libethe-
nite, Lunnite, Demidoffite, and Torber-
nite.
Phosphate of Iron. See Vivianite,
Beraunite, and Childrenite.
Phosphate of Lead. See Pyromorphite.
Phosphate of Lime. See Apatite.
Phosphate of Uranium. See Autunite
and Torbernite.
Phosphorescence. When minerals ap-
pear luminous under certain conditions
they are said to be phosphorescent. This
property may be produced by —
1. Friction. Ex. Quartz (frictio-phos-
phoric).
2. Heat. Ex. Fluor (pyro-phosphoric).
3. Electricity. Ex. Apatite (electro-
phosphoric).
4. Exposure to sunlight. Ex. Dia-
mond, Calcite (helio-phosphoric?).
Phosphorite. See Apatite.
Physical Characters of Minerals. A
convenient sub-division of the characters
of minerals is into —
1. Physical.
2. Chemical.
3. Optical.
The chief physical characters are —
1. Form, 5. Hardness,
2. Cleavage, 6. Specific gravity,
3. Fracture, 7. Magnetism,
4. Frangibility, 8. Electricity.
PIGOTITE.
Amorphous ; incrusting ; brown ; streak
and powder yellow.
B. , etc. In matrass gives off water ;
on C burns away slowly, leaving a small
quantity of white ash, which, when
treated with Co, turns blue ; insoluble
in water or alcohol ; soluble in HC1 (?).
Comp. A hydrated Mudesite of alu-
mina, the formula of which is said to be
4A1203 + C12H508+27H2.
Loc. Some of the granite caves of the
coast of Corn .vail.
Obs. It can hardly be considered a
mineral. It has been observed in places
where the surface-water trickles down
over the granite rocks. "The organic
constituent of Pigotite is considered by
James F. Johnston to be derived from
the decay of the various plants which
grow on the moist moorlands above, and
which being carried by the waters into
fissures in the granite beneath, combines
with the alumina of the decomposed fel-
spar, and when it reaches the air depo-
sits itself over the roof and sides of the
cavern in the form of layers, varying
from two to three inches in thickness."
(Bristow's Gloss. Min., p. 288.)
PINITE.
Khombic ; usually in six or twelve -
sided prisms, sometimes with the termi-
nal edges modified (Fig. Ill); sectile or
brittle ; fracture uneven ; translucent to
opaque ; dull, glimmering, or waxy ; re-
sinous or pearly ; greyish, greenish, or
dark brown ; streak white or grey : H.
2-3; G. 2-7-2-9.
B., etc. In matrass gives off a little
H2O ; on C loses colour, and fuses on
thin edges to a blistered glass or enamel;
with Co turns bluish ; with borax yields
Fe reactions ; imperfectly decomposed
by HC1.
Comp. No analysis of a British spe-
cimen is known to the author, but foreign
specimens contain from 47 "0 to 56 "0 per
cent, of silica, 25 "0 to 29 '0 per cent, of
alumina, 7'0 to 8'0 per cent, of protoxide
of iron, 6'0 to 10 "0 per cent, of potash,
and 2'0 to 8'0 per cent, of water. This
composition differs scarcely at all from
that of some Agalmatolites, with the ex-
ception of the iron.
Loc. Trewellard Cliff, St. Just ; the
high hills south of Trewellard, in granite
(Trans. Roy. Geol. Soc. Corn., J. Carne,
vol. ii); Nangisel Cove, Sennen; Mulvra-
hill, near Sancreed ; in the rocks to the
east of Lamorna Cove, in small dark
brown crystals, like Fig. Ill ; Tol Pedn
Penwith; St. Michael's Mount; in im-
bedded crystals in an elvan running
through St. Hilary and Breage, by Tre-
goning-hill, and in another running from
Tregurtha to Praa Sands ; these elvans
are largely used for road material, and
good specimens may sometimes be ob-
tained in the heaps by the roadside ; be-
tween St. Austell and Grampound, in an
elvan running from Polgooth, by Trewi-
then, to Court Mill ; found also in Scot-
land, and many foreign localities.
O65. Dana includes Finite with Agal-
matolite and many other minerals in a
group of hydrous alkaline silicates, re-
lated chemically and physically to ser-
pentine. He observes that it occurs in
pseudomorphous crystals after lolite,
Neph elite, Scapolite, Felspar, and Spodu-
mene. Some of the Breage specimens
have a bluish colour, and considerable
lustre.
Angles.
MM' = 119° 10' ab = 90° 00'
MO 90 00 ad 150 25
Ma 120 25 dd' 120 50
Or 132 12
78 PITCHBLENDE.
POLYBASITE.
Sometimes a face r is observed in the
crystals from Lamorna, which truncates
the angle M O.
PITCHBLENDE.
[Uranium. Pechurane.] Cubic (?) or
amorphous ; botryoidal, reniform, mas-
sive, or disseminated ; columnar, curved,
lamellar, or granular ; brittle ; fracture
uneven or small conchoidal ; opaque ;
lustre metallic, sub-metallic, or dull ;
greyish, greenish, or brownish-black ;
H. 5'5; G. 6-4-7.
B., etc. In matrass no change ; on C
infusible ; with borax gives a yellow
bead in OF ; greenish in RF ; with
micro, gives U reactions ; insoluble in
HC1 ; soluble in warm Aqua Regia, or
hot HNO3, forming a yellow solution.
Oomp. Proto-peroxide of uranium.
No analysis of a British specimen is
known to the author. With uranium
8478 and oxygen 15 '22 the formula
would be TJ + Ua or U3O4.
Loc. Huel Edward, St. Just (many
years ago and again recently) ; Botallack,
formerly ; Huel Trenwith ; Huel Provi-
dence ; Wherry Mine ; Tincroft, with
autunite ; Huel Basset ; Huel Buller ;
Tolcarne; Ting Tang; Pednandrea(mam-
millary); Roskrow United, Ponsanooth ;
St. Austell Consols; Treemoor, Withiel;
found also in Norway, Sweden, Ger-
many, and many other foreign localities.
06s. It may be distinguished from
blende by its sp. gr. and fracture ; from
wolfram by its fracture and streak. It
is used for enamel painting, colouring
glass for optical purposes, &c. It is often
associated with ores of silver, lead, and
copper.
Pitch Ore. See Pitchblende.
PITTICITE.
[Pitchy Iron Ore.] Amorphous ; reni-
form, stalactitic, or massive ; brittle ;
fracture flat conchoidal or earthy ; trans-
lucent on edges to opaque ; lustre vitre-
ous, resinous, or dull ; yellow, reddish,
or blackish-brown ; streak pale yellow ;
H. 2-3; G. 2-3-2-4.
B., etc. In matrass gives off H2O and
yields a white sublimate, often crystal-
line ; on C melts readily to a dark mag-
netic globule, giving off copious white
fumes with an alliaceous odour, and de-
positing a white coating on the cool part
of the charcoal support ; soluble in warm
HC1 or HNO3.
Comp. Hydrated arseniate of iron, of
very variable and uncertain composition.
Loc. Dolcoath, formerly ; specimens
were found in the year 1866, by Dr. C
Le Neve Foster, which were at first soft
and plastic, but soon became harder, and
fell to pieces ; these are of a greyish-
yellow colour. Found also in France,
Germany, and many other localities.
06s. It is probably a product of the
decomposition of mispickel, with which
some parts of Dolcoath abound.
Plastic. Capable of being moulded
like clay.
Plumbago. See Graphite.
PLUMBIC OCHRE.
[Earthy Lead Ore.] Amorphous; mas-
sive ; compact or earthy ; opaque ; dull ;
yellow, brownish, or bluish -brown ; streak
the same; H. 0-2; G. 8U
B. , etc. In matrass unchanged ; on C
easily reduced to a malleable bead of
lead ; soluble in HNO3 without efferves-
cence.
Comp. Anhydrous oxide of lead.
Loc. " Earthy Lead Ore " was found
about the year 1820 in Huel Mexico,
Perranzabuloe ; it was " amorphoxis, or
in minute six-sided prisms (Plattnerite?)
in cavities in ferruginous quartz;" the
colour was straw-yellow or greenish-
yellow. A specimen analysed by Mr.
Michell yielded 20 '2 per cent, of lead,
24 '6 per cent, of iron, 2 '4 per cent, of
silver, 37 "0 per cent, of silica, and 14 '0
per cent, of oxygen, with a trace of
chlorine.
Plush Copper. See Cuprite (Chalco-
trichite).
Podar. An old Cornish term for py-
ritous dust or waste.
POLYBASITE.
Hexagonal (Nicol) or Rhombic (Dana);
usually in short tabular prisms, the bases
striated parallel to the alternate edges ;
also massive or disseminated ; fracture
uneven ; opaque, or translucent in very
thin pieces ; lustre metallic ; iron-black ;
thin plates cherry red by transmitted
light; streak iron-black; H. 2-2 '5; G.
6-0-6-25.
B., etc. In matrass decrepitates and
fuses ; in tbe open tube yields a sul-
phureous odour and a yellow or reddish
sublimate ; on C deposits a white coating
of the oxides of Sb As or. Zn, fusing,
boiling, and yielding finally a white me-
tallic alloy ; with micro, gives indications
of Cu ; by cupellation a bead of silver ;
decomposed by HNO3.
Comp. Anhydrous sulph-antimonide
of silver and other bases. A Cornish
specimen yielded to Joy the following
results : —
POLYTELITE.
PSETJDOMOEPH. 79
Sulphur 15*87
Antimony 5"46
Arsenic 3'41
Silver 72'01
Copper 3'36
Iron ... 0-34
Total 100-45
Loc. "Cornwall" is given as a loca-
lity of Polybasite by Dana, but this may
refer to a Cornwall county in the United
States.
Polytelite. See Fahlerz.
Porcelain Clay. See Kaolin.
Porcelain Jasper. A highly indurated
clay, much resembling true Jasper, but
containing a large proportion of alumina.
PORCELLANITE.
[Porcelain Spar.] Rhombic (Brooke),
prismatic angle 88°, or tetragonal (Dana),
two cleavages forming right angles ; also
massive, compact, or columnar ; brittle ;
fracture uneven: transparent to opaque;
lustre vitreous, pearly, or greasy ; white,
grey, greenish, bluish, reddish ; H.
5-5-6; G. 2-6-2-74.
B., etc. In matrass yields a little
water ; on C loses colour, and fuses at
from 3 to 4 to a blebby glass ; treated
with Co turns blue ; imperfectly decom-
posed by HC1.
Comp. Silicate of alumina, lime, and
soda, with perhaps silica 50'6 per cent.,
alumina 28 '1 per cent., lime 15 '6 per
cent., soda 5 '7 per cent.
Loc. It is said to have been found
near Redruth(?). It occurs in Norway,
Sweden, and many foreign localities.
Obs. It is readily decomposed by ex-
posure to air and moisture, and con-
verted into friable porcelain earth, which
frequently retains the form of the
crystals.
Potash Mica. See Muscovite.
Potato Stone. See Geode.
Porphyry. Any rock which contains
disseminated crystals distinct from the
main mass. Thus there may be fel-
spathic porphyry, claystone porphyry,
granitic porphyry, &c. The _ Cornish
elvans are usually porphyritic. The
term was originally applied to a reddish
or purplish syenitic porphyry found in
Upper Egypt.
Porphyritic. See Porphyry.
Potstone. See Steatite.
PREHNITE.
Rhombic ; in prisms (Fig. 96), striated,
or closely aggregated laterally ; cleavage
basal, perfect ; often botryoidal, reni-
form, or radiated ; brittle ; fracture un-
even ; translucent to transparent ; lustre
vitreous or pearly; white, or various
shades of pale green or yellow; streak
white; H. 6-7; G. 2 '9-3; pyro-electric.
B. , etc. In matrass gives off H2O ; on
C fuses at about 3 to a blistered glass,
with effervescence ; scarcely acted upon
by acids until after ignition, when HC1
completely decomposes it, gelatinous
silica being deposited.
Comp. Hydrated silicate of alumina
and lime. With silica 43 '0 per cent.,
alumina 24 '4 per cent., lime 28 '4 per
cent., and water 4 "2 per cent., which is
pretty nearly what is yielded by Scottish
specimens, the formula may be written
A12, 3Ca, 3
Loc. Roscommon cliff ; a vein in the
cliffs between Botallack and Huel Cock,
with stilbite and mesotype ; Botallack,
Huel Cock, Levant, all in St. Just,
formerly, in pale green groups of crys-
tals ; fine specimens are found in Scot-
land, Ireland, and many foreign locali-
ties.
Angles.
MM 100° 00' if 92° 00'
Me 128 33 Mi 91 30
ij 177 20
Prism. A solid figure, the base of
which is any right-lined figure, while the
sides are parallel. Figs. 2, 110, 111,
171, &c., are prisms. In mineralogy
very short prisms are called tables, and
the crystals are said to be tabular.
Prismatic Arseniate of Copper. See
Olivenite.
Prismatic Arsenical Pyrites. See Mis-
pickel.
Prismatic Bismuth Glance. See Bis-
muthinite.
Prismatic Cobalt Mica. See Erythrite.
Prismatic Copper Mica. See Chalco-
phyllite.
Prismatic Iron Pyrites. See Marca-
site.
Prismatic System. See Crystallogra-
phy : Rhombic System.
Prismatic Talc Mica. See Chlorite.
Prismatoidal Manganese Ore. See
Manganite.
Protoxide of Uranium. See Pitch-
blende.
Pseudomorph. A substance having
the form of one mineral and the compo-
sition of another. The chief kinds are
those which are —
1. Pseudomorphs by loss of an ingre-
dient, as when LiMONiTE is found in the
form of CHALYBITE. Such specimens
have been found in several mines at St.
Just, and other places in the two coun-
ties.
80 PSEUDOMOBPH.
PSEUDOMOBPH.
2. Pseudomorphs by gain of an ingre-
dient, as when LiMONiTE occurs in the
form of HEMATITE. This is no uncom-
mon condition of Limonite in many iron
mines.
3. Pseudomorphs by exchange of in-
gredients, as when GALENA occurs in the
form of PYKOMORPHITE. Very fine exam-
ples of this change occurred at Huel
Hope, in the year 1827.
In some specimens of Limonite after
Pyrites ; and in those of Felspar after
Chlorite, observable in the granite of the
north and western flanks of Carn Marth,
the change often appears to commence in
the centre and to proceed outwards.
Sometimes this change proceeds until the
whole of the original substance is replaced
by one of totally different composition,
as when Quartz, Calcedony, or Horn-
stone appear in the form of Fluor. Thus,
Mr. J. Carne states that in some cubic
Quartz found at Botallack is a crystal
"in which the acuminated angles often
seen in Fluor are well preserved.1'
(Trans. Eoy. Geol. Soc. Corn., vol. II.)
4. Pseudomorphs of dimorphous sub-
stances, as when CALCITE is found in the
form of AKAGONITE.
5. Pseudomorphs by incrustation,
formed as moulds on the surface of other
minerals. These are often hollow, and
sometimes contain fluids. In some speci-
mens of Calcedony in hexagonal tabular
crystals from Balleswidden, in one "the
calcedony is merely a deposit on Calcite,
which is everywhere visible ; in the
other, where the Calcite is seen at all,
the line of it is but just perceptible, and
in some parts is wholly gone, and the
solid crystal of Calcedony remains. "
6. Pseudomorphs by infiltration,
formed as casts within the moulds men-
tioned in 5.
7. Pseudomorphs after organic forms,
as when the substance of a fossil is re-
placed with mineral matter.
With these, the arborescent forms
often met with in native copper
and native silver must not be con-
founded. Such forms are in no way
connected with organization, they are
simple dendritic accretions, analagous
to those of water on a window pane on a
f rosty'night. Of this kind were, probably,
some specimens of metallic copper,
in the form of plants, from Treskerby,
*' The stem, and often the fibres of the
leaves, were very perfect," so that "a
good botanist might almost venture to
give the names and descriptions of the
plants." (J. Carne, Trans. Roy. Geol.
Soc. Corn., voL II.)
The following is as/ complete a list of
Devonshire and Cornish Pseudomorphs
as the author has been able to obtain.
Where it was possible, he has indicated
the class in which the specimen should
be placed, but in some instances no par-
ticulars were obtainable : —
Group 1. Pseudomorphs by loss of
ingredients —
In the form of — Locality.
1 Limonite, Chalybile, St. Just.
2 ,, ,, Perran Iron Lode
3 „ Garnet, Belstone Consols.
AUTHORITIES.— 1, J. Carne (Trans. Roy.
Geol. Soc. Corn., vol. vi.); 2, Prof. Smyth
(ibid. vol. vii., p. 336); 3, J. Davis, Brit. Mus.
(private information).
Group 2. Pseudomorphs by gain of
ingredients —
In the form of— Locality.
1 Limonite, Hematite(?)Reatormel. (?)
This locality is doubtful. The author has
seen a well-marked specimen which is said
to have come from there.
Group 3. Pseudomorphs by gradual
exchange of ingredients —
In the form of — Locality.
1 Limonite, Pyrites,
Levant.
Huel Owles.
Trecrobbeu Mine
Carnmarth.
Huel Ruby.
Restormel.
Huel Maudlin.
4 Oxide of Iron,Felspar,
5 Hematite, Calcite,
6 Goeihite, Pyrites,
7 Wolfram, Scheelite,
8 Galena, Pyromorph.JlueUlope.
9 Chalcopyrite, Chalcocite, St. Ives Consols.
10 Cerussite, Galena,
11 Cassiterite,
12
13
14
15 Chlorite,
16
17
18
19 Calcedony,
20
21
22 Kao n,
23
24
25
26
27
28 ScAorZ,
AUTHORITIES.— 1, 10, 14, 19, 20, J. Carne
(Trans. R. G. S. C., vol. vi.); 2, 6, 13, 16, 28,
R. Pearce (Rep. Roy. Inst. Corn., 1861, 1863,
and private information); 5, Prof. Smyth
(private information); 18, 26, Prof. Church
(ditto); 7, Greg and Lettsom, (p. 354); 8,
Michell (Man. Min., Truro, 1825, p. 9); 11,
W. M. Tweedy (Rep. Roy. Inst. Corn., 1841,
p. 39); 12, T. M. Hall (Min. Direct., p. 131);
3, 4, 9, 15, 17, 22, 23, 24, 25, 27, the author has
himself seen, recently, many in situ.
Group 4. Pseudomorphs of dimor-
phous substances.
No example from Devon or Cornwall known
to the author.
Felspar,
Huel Coates.
n
Carn Brecon.
Balleswidden.
Quartt,
Huel Primrose.
Felspar,
Carnmarth.
United Mines.
Pennance.
Carclaze.
Calcite,
Balleswidden.
Datholite
Haytor.
North Roskear.
Felspar,
Balleswidden.
}}
Tregoning hill.
if
Tremearne.
Vogue.
|
"
Carclaze.
St. Stephens.
Felspar,
St. Enoder.
PSEUDOMORPH.
PSEUDOMORPH. 81
Group 5. Pseudomorphs by incrusta-
9 Quartz, Fluor, Huel Sparnon.
ttow, —
10 ,, ,, BeerftTris.
11 South Hooe.
In the form of — Locality.
12 Beeralstone.
1 Quartz, Fluor, Huel Spearn.
13 ", Calcite, Gwennap.
2 „ ,, Botallack.
14 „ „ St. Ives Consols.
3 Caruidjack.
15 ,, ,, Botallack.
4 Huel Alfred.
16 Hay Tor.
6 „ Huel Herland.
17 ,, Dolomite, Levant.
6 „ , United Mines.
18 Huel Cock.
7 „ , Consolidated Ms.
8 , ,, Trevaseus.
9 , North Roskear.
19 ,, Felspar, Boscagel Downs.
20 Calcedony, Calcite, North Roskear.
21 ,, ,, Near Penzance.
10 , „ North Pool.
22 Hay Tor.
11 , „ Dolcoath.
23 ',', Dolomite, North Roskear.
12 , „ Huel Trelawny.
24 ,, Levant.
13 , „ Huel Mary Ann.
14 ,, ,, Near Holrnbush.
15 „ Chalybite Botallack.
25 ,, Barytes, Herodsfoot.
26 ,, ,, Huel Mary.
27 Limonite, Calcite, S. Huel Basset.
16 ,, „ Dolcoath.
17 ,, ,, Cook's Kitchen.
28 ,, Pyrites, Hennock.
9(\ Bottilhick
18 Calcedom}, Fluor, Craft-an-verth.
30 " S. Huel Basset.
19 „ Galcite, Balleswidden.
20 Chalybite, SelenitQ, Virtuous Lady.
31 „ Chalybite, Huel Owles.
32 ,, D ilomite, „
21 ,, ,, Beeralstone.
22 „ „ Huel Friendship.
23 „ Fluor, Virtuous Lady,
24 „ Galcite, Beeralstone.
33 Goethite, Pyrites Restormel.
34 Pyrites, Chalybite, Restormel.
35 ,, Calcite, Huel Mary.
36 ,, Tavistock.
25 Pyrites, „ Herodsfoot.
26 Quartz, Chalybite, Cousol. Mines*
37 " Albite, Consolidated Ms.
38 ,, Barytes, Herodsfoot.
AUTHORITIES. — 1, 2, 4, 9, 18, 19, J. Came
39 Marcasite, Calcite^ Tamar Mine.
(Trans. R. G. S. G., vol. vi.); 3, 15 (ibid. vol.
40 Chalybite, Calcite, Beeralstone.
ii.); 5, 6, 8, 10, 11, J. Garby (ibid. vol. vii., p.
73); 12, 13, 16, 17, R. Pearce (private informa-
tion); 14, 25, Prof. Smyth (ditto); 20, 22, 23,
24, Greg and Lettsom (p. 260); 7, 26, 11. W.
41 „ Fluor, Fowey Consols.
42 ,, Dolomite, Huel Owles.
43 Hornstone, Fluor, Beeralstone.
44 Chlorite, Magnetite, North Roskear.
Fox, F.R.S. (Rep. R. C. P. S., 1845, pp. 2, 7).
Group 6. Pseudomorphs by infiltration.
45 ,, „ Tresavean.
46 ,, Albite, Consolidated Ms.
47 ' „ Axinite, St. Just.(?)
In the form of — Locality.
48 ,, ,, Dartmoor.
1 Cassiterite, Felspar, Huel Coates.
2 Quartz, Fluor, Consol. Mines.
49 Chalcopyrite, Blende, Levant.
50 „ ' „ Huel Alfred.
Sometimes " the infused portion of Tin-
51 „ Chalybite, Levant.
stone has not sufficed to fill the cavity left by
the Felspar, in which case crystallization has
52 ,, Fahlerz, „
53 „ ,, Crinnis.
taken place, and the Tinstone has assumed
its ordinary form." (W. M. Tweedy, Rep.
54 ,, Chalcocite, ,,
55 „ Dolomite(?)H\iel Tolgus.
Roy. Inst. Corn. 1841, p. 39.)
AUTHORITY.— 2, R. W. Fox, F.R.S. (Rep.
56 „ ,, St. Just.
57 Malachite, Cent-suite, Near Redruth.
58 Halite, t Near Blackbrook
R» C. P. S., 1845, p. 2).
59 M ? Near Sidmouth.
Group 7. Pseudomorphs after organic
60 Finite, lolite, Breage.
forms—
61 ,, ,, Lamorna.
In the form of— Locality.
1 Calcedony. Animal
forms, Torquay.
2 „ „ Broadhembury.
3 „ ,, Livermead Head.
4 „ „ Paignton Harbr.
6 „ Shells, Haldon.
62 ,, „ St. Hilary.
63 Trewellard.
64 „ , MulvraHill.
65 , TolPedn Pen with
66 '„ , St. Michael's Mt.
67 „ , Tregoning Hill.
63 Jf , Nr. Grampound.
6 Copper, Plants, (!) Treskerby.
7 (?) Gondurrow.
69 , Sennen.
70 Mica, P nite, Nr. Land's End.
AUTHORITIES.— 1, 2, 5, Prof. Church (Phil-
71 Fluor Felspar
Mag., 1864, and private information); 3, 4,
W. Pengelley (Trans. R. G. S. C., vol. vii., p.
311); 6, 7, J. Carne (ibid. vol. ii.).
AUTHORITIES.— l, 6, 8, 11, 14, 17, 20, 24, 28,
29, 30, 40, 41, 49, 51, 52, 57, T. M. Hall, F.G.S.
(Min Direct, pp. 130 131); 2, 3, 4, 5, 7, 9, 10,
No particulars obtainable—
12, 13, 16, 21, 22, 23, 25, 26, Greg and Lettsom
1 Quartz, Fluor, St. Agnes.
2 „ „ Gt. Crinnis.
p 95, et seq.y, 27, 30, 31 (ibid* p. 255); 32, 33,
38, 42, 53, 67, 70, 71, R. Pearce (Rep. R. I. C.,
3 ,, ,, South Caradon.
andprivateinf.);15, 18, 19, 43, 44, 54, 55,.T. Carne
4 ,, ,, Cam Brea.
(Trails. R. G. S. C., vol. ii.); 69, Prof. Smyth
5 ,, ,, Balleswidden.
(private information); 68, De la Beche (Rep.
6 ,, ,, Spearn Moor.
on Cornwall, &c.); 58, 59, G. W. Ormerod
7 ,, ,, Trehane.
(Rep. Dev. Assoc., vol. iii., p. 78); 45, 60, 67,
8 ,, ,, Perranzabuloe.
the author has himself obtained.
82 PSILOMELANE.
PYEITES.
Many of the pseudomorphs referred to
are given on the authoiifcy of several
mineralogists, although only one is men-
tioned in each case.
PSILOMELANE.
[Black Hematite. Compact Grey Oxide
of Manganese.] Amorphous ; botrvoidal,
stalactitic, or massive ; surfaces often
smooth; tough; fracture conchoidal, un-
even, or even ; lustre metallic, sub-me-
tallic, or silky ; dark steel-grey to iron-
black ; streak brownish-black and shin-
ing ; H. 5-6; G. 4-4-4.
B., etc. In matrass yields a little
water ; on C infusible ; with borax and
soda gives Mn reactions ; soluble in warm
HC1, with evolution of Cl.
Comp. An impure peroxide of man-
ganese of variable composition, often
containing baryta and water. No analy-
sis of a specimen from Cornwall or Devon
is known to the author.
LOG. Restormel Royal Iron Mines, in
splendid velvet- black stalactitic masses ;
Lif ton, near Launceston ; Creva Wood ;
St. Minver ; Huel Bucketts ; Pednan-
drea ; Huel Tolgus ; and other mines in
Cornwall.
Black Down and Brent Tor, in
fine botryoidal and stalactitic masses ;
East Down, Georgeham, West Down,
and Viveham, near Barnstaple ; near
Bideford; Orleigh Court, Buckland
Brewer ; Blackdown ; Upton Pyne, near
Exeter ; Chudleigh ; Ashton, &c. It
also occurs in Ireland, Germany, Nor-
way, North America, &c.
Obs. It usually occurs associated with
Manganite, Pyrolusite, and Wad. Some
Cornish specimens occur in concentric
layers, alternating with Pyrolusite or
Wad. It may be easily distinguished from
Pyrolusite and Wad by its hardness; from
Hematite by the colour of its streak;
and from Magnetite and Pitchblende by
its reactions with soda and borax.
Purple Copper. See Erubescite.
Pyramid. A solid figure, whose base
is any right-lined figure, and whose sides
are all triangles. A pyramid in crystal-
lography comprises two such figures,
piaced base to base, i.e., a double pyra-
mid. Fig. 1, the octahedron, is a pyra-
mid with square base, the sides of which
are equal equilateral triangles.
PYRARGYRITE.
sometimes dendritic, micaceous, dissemi
Dated, or massive ; brittle, or almost sec-
tile ; fracture conchoidal or uneven ; trans-
lucent to opaque ; lustre sub-metallic,
adamantine, or resinous ; dark red, lead-
frey, or iron-black ; streak dark red ; H.
-2-5; G. 57-5-9.
B., etc. In matrass decrepitates, and
gives a reddish sublimate ; on C fuses at
j 1, gives off a sulphureous odour, deposits
a copious white incrustation of oxide of
antimony ; after long roasting yields a
bead of Ag ; insoluble in HC1 ; decom-
posed by HNO3 ; the powder becomes
black if treated with KHO.
Comp. Anhydrous sulphide of silver
and antimony. With silver 59 '9 percent.,
j antimony 22'5 per cent., and sulphur
I 17 "6 per cent, its formula may be
| SbAgsSs or SbAgs3.
Loc. Huel Herland, formerly, in small
i crystals, and granular ; Mount Mine ;
j North Dolcoath ; Dolcoath ; Huel Mexi-
i co ; Huel Ludcott ; Holmbush ; Huel
Brothers ; Huel Duchy, Callington, in a
i cross-course, both crystallized and mas-
sive, with native silver, native c.ipper,
and black sulphide of silver. It has been
found sparingly in Sark, also found in
France, Germany, Chili, Peru, and other
. foreign localities.
Obs. It may be readily distinguished
from Cuprite by its blowpipe reactions ;
i from Chalcocite and Galena by its streak ;
; from Tennantite by the crystalline form
j of the latter.
Angles.
e e' = 137° 58' a a' == 120° 00'
eR 144 21
PYRITES.
[Dark Red Silver Ore. Antimonial Sil-
ver Blende. Rubin-Blende (in part).]
Hexagonal ; in prisms variously modified,
and of ten macled (Figs. 213, 214); cleav-
age rhombohedral, perfect (R = 103° 42');
[Iron Pyrites. Mundic. Sulphide of
Iron.] Cubic ; in forms resembling Fi°-s.
1, 2, 4, 8. 9, 16, 32, 43, 45, 46, 47, 48, 50,
i 52 ; the faces often striated or rough ;
j macles like Fig. 58 not uncommon ; often
j drusy on other minerals ; also massive
or compact ; sometimes spheroidal, bo-
; tryoidal, radiated, stalactitic, fibro-la-
mellar or cellular ; brittle ; tough ; frac-
j ture conchoidal, uneven, or splintery ;
opaque ; lustre metallic, splendant,
sometimes shining or glimmering; brass-
yellow ; occasionally greenish-yellow or
( iridescent ; streak black or greenish-
j black ; H. 6-6 5 ; G. 4'S-51 ; gives off a
I sulphureous odour when broken, and is
| hard enough to give sparks when struck
i with steel.
Var. 1. Auriferous Pyrites is a varie-
I ty containing a notable proportion of
gold.
PYEITES.
PYBOLUSITE.
83
2. Argentiferous Pyrites contains sil-
ver.
3. Hepatic Pyrites is a variety of a
brown colour, and partially converted
into Limonite.
B., etc. In matrass gives a sublimate
of S, which readily melts into brownish-
yellow drops; turns black; on C fuses
at I, burns with a blue flame, forms a
dark brittle magnetic globule, with a
crystalline surface when cool; with borax
gives Fe reactions ; scarcely acted upon
by HC1, nor by HISTO^ until finely pow-
dered, when it dissolves, forming a green-
ish-yellow solution.
Comp. Anhydrous per-sulphide of
iron. Common as it is, but few or no
analyses of Cornish or Devonshire spe-
cimens are on record, at least within the
knowledge of the author. With sulphur
= 54 '25 per cent. , and iron 45 "75 per cent,
the composition would be indicated by
FeS2.
LOG. Fine specimens have occurred
from time to time at Botallack, Levant,
Huel Spearn, and other St. Just mines ;
at Providence Mine and West Poldice ;
Huel Darlington ; Mount Mine ; Great
Work, Godolphin, Huel Vor, and other
mines in Breage (Figs. 2, 43, and 45, im-
bedded in chlorite, as well as other
forms); Huel Herland, Gwinear ; Huel
Trannack ; Huel Prospidnick, Sithney,
in chlorite (Fig. 45); Cadgwith ; Bellu-
rian Cove, near Mullion, in a conglo-
merate, with native copper ; Dolcoath,
Cam Brea, Tincroft, East Pool, and most
of the mines in Camborne and Illogan ;
Huel Unity, Ting Tang, Tresavean, and
most of the mines in Gwennap ; Huel
Buller, Copper Hill, Pednandrea, and
other Redruth mines ; Creegbrawse ; Huel
Jane ; Huel Falmouth ; Nangiles ; Re-
tallack, Huel Golden, and other mines
in Perranzabuloe ; St. Agnes, magnetic,
in cubes? of one inch, formerly (J. Garby,
Trans. R. G. S. C., vol. vii., p. 82); Fovvey
Consols ; Polgooth ; Lanescot ; Crinnis ;
Pembroke ; Great Dowgas ; Huel Maud-
lin ; Herodsfoot ; Huel Maria, in chlo-
rite, deeply striated and iridescent.
Huel Friendship ; Combemartin ; Vir-
tuous Lady, Bedford United, and other
mines near Tavistock ; Huel Robert,
Sampford Spiney ; Parracombe, in trap
ash ; Bishop's Tawton, Venn, Bicking-
ton, Viveham, and other places near
Barnstaple, disseminated in the rocks ;
near Tiverton, in a quarry, in the inte-
rior of fossil shells ; in the cliffs to the
west of Axmouth, &c.
Stalactitic Pyrites occurs at East Pool
and other localities.
Pyrites occurs pseudomorphous after
calcite near Tavistock and other places ;
after fluor at Beeralstone, &c.; after
albite at the Consolidated Mines, Gwen-
nap, &c. See Pseudomorphs.
Obs. It is, in small quantities at least,
almost universally distributed in metal-
liferous districts ; few mines being abso-
lutely without specimens. It may be
readily distinguished from Gold by its
hardness and brittleness ; from Chal-
copyrite by its hardness ; from Marcasite
it can only be distinguished with cer-
tainty by its crystalline form (Marcasite
is, however, said to be more often radi-
ated and fibrous, of a paler colour, often
greenish, and much more liable to de-
composition. It is largely used in the
manufacture of sulphuric acid.
A nyles.
00 = 109° 28' e o = 140° 16'
a a 90 00 ov 157 47
o a 125 16 k o 160 32
ae 153 26 kk 148 50
The cube Fig. 2, octahedron Fig. 1, pen-
i tagonal dodecahedron Fig. 43, and Figs.
j 45, 46, 47, 48, 52 are the most common
I forms.
Pyritous Copper. An old name for
Chalcopyrite.
Pyro-electric. Minerals which become
electric by heating are so called. Ex.
Tourmaline.
PYROLUSITE.
Black Oxide of Manganese. Anhy-
drous Bin oxide of Manganese.] Rhom-
bic ; rarely crystallized distinctly ; some-
times in crystals, like Figs. 136, 137 ; a
Cornish specimen in the author's collec-
j tion like Fig. 242 ; botryoidal, reniform,
: columnar, fibrous ; massive, compact,
' granular, or earthy ; brittle ; fracture
I uneven ; opaque ; lustre metallic, sub-
! metallic, or silky ; steel-grey, to iron or
J bluish-black ; soft enough to soil the
fingers when handled; H. 2-2 '5 ; G.
47-5-0.
B., etc. In matrass unchanged, or
gives off a little water: onC unchanged,
or turns reddish ; with soda arid borax
gives Mn reactions ; soluble in HC1,
with evolution of Cl.
Comp. Anhydrous manganic dioxide,
with often small quantities of oxides of
j iron and baryta AVhen pure the com-
position will be manganese 63 '3 per cent.,
oxygen 36 '7, when the formula may be
written Mn2 or Mn2O3.
LOG. Tregony, Very an ; Restormel ;
Indian Queens, Creva Wood, Callington ;
Lifton and Trebartha, near Launceston ;
84 PYEOMORPHITE.
PYROXENE.
Tresweeta, St. Stephens ; near Calstock ;
and most of the manganese mines of East
Cornwall.
Tavistock ; Brent Tor (on Psilomelane);
Upton Pyne, near Exeter ; Georgehamand
Viveham, near Barnstaple ; Newton St.
Cyres, Doddiscombleigh, and Ashton,
near Chudleigh ; and other Devon loca-
lities. (" Manganese" occurs near Buck-
f astleigh ; Dean Church, south of Buck-
fastleigh; LewTrenchard ; Leigh Down ;
East Cot Beacon ; Higher Chillaton ;
Narracol ; "VVick ; Bowdon Down, south
of Marystow, &c. See Ordnance Map. )
Foreign localities very numerous.
(>bs. It may be distinguished from
Psilomelane and Manganite, with which
it is usually accompanied, by its inferior
hardness ; from Antimonite and Jameso-
nite by its infusibility. It is largely used
in the preparation of chloride of lime,
for bleaching purposes; and for glass
making.
A riffles.
MM' = 93° 40' MO= 90° 00'
Od 128 45
P YROMORPHITE.
[Brown Lead Ore. Green Lead Ore.
Phosphate of Lead] Hexagonal; in
horizontally striated prisms, with the
terminal edges often replaced, and the
basal plane concave or rough (Figs. 188,
190, 192); also globular, reniform, botry-
oidal, or massive ; brittle ; fracture im-
perfei-t conchoidal ; semitransparent to
translucent on thin edges only ; lustre
resinous to adamantine ; splendanfc to
glimmering; various shades of green,
grey, yellow, or brown ; streak white, or
pnle yellowish, or greenish-brown ; H.
3-5-4; G. 6-5-71.
jB., etc. In matrass darkens ; on C
fuses at 1 to a bead which crystallizes
suddenly on cooling, tinging the flame
green on the edges ; with soda yields a
bead pf Pb ; sometimes gives off an allia-
ceous^ odour ; when fused with oxide of
copper yields a beautiful blue flame ; in-
soluble in HC1 ; soluble in HNO3.
Comp. Anhydrous chlorophosphate
of lead No analysis of a specimen from
Devon or Cornwall is known to the
author, but foreign specimens yield
nearly 15 '6 per cent, of phosphoric an-
hydride, 81 "8 per cent, of oxide of lead,
and 2 '6 per cent, of chlorine. With
these proportions the formula will be
similar to that of apatite, viz., 9Pb3P2-f
PbCl2 or PgOgPbo/PbCaO.
Loc. Very fine crystals, formerly, at
Huel Alfred, and Huel Hope (mostly
changed into galena); more recently at
Huel Rose and Hnel Penrose, Sithney ;
Penberthy Croft; Huel Bell ; Huel Kea;
Huel Falmouth ; Huel Golden ; Beer-
alstone, in grey masses, with mimetite,
&c. It is found also in Derbyshire,
Yorkshire, Cumberland, Wales, and
many foreign localities.
<>bs. The phosphoric anhydride is very
frequently replaced in part by arsenic
anhydride, especially in the yellow, grey,
or brown specimens. Sometimes the lead
is largely replaced by lime, when the sp.
gr. is much below that given above.
Angles
a a' = 120° 00' O x = 139° 38'
Oa 90 00 xx' 142 12
xa 130 22 ba 150 00
Pyrophosphoric. A term applied to
substances which " phosphoresce " on
heating. Ex. Fluor, especially Chloro-
phane.
PYROXENE.
[Augite. Diallage, in part. Malaco-
lite Sahlite ; &c.j Oblique ; when
crystallized usually in modified prisms
(augite like Figs. 160, 161); cleavage par-
allel to M, tolerably perfect ; the faces
a b often striated longitudinally ; macles
not uncommon ; brittle ; fracture con-
choidal or uneven ; sometimes transpa-
rent, but more usually translucent or
opaque ; lustre vitreous, sometimes co-
lourless, but more usually grey, green,
dark brown, or black ; streak white to
grey; H. 4-6; G. 3 '2-3 '3.
Var. 1. Augite. Often dull, dark
green, or nearly black, and opaque ;
usually fusible at about 2. Usually con-
tains notable quantities of alumina.
2. Diopside. Green and transparent ;
very brilliant.
3. Sahlite. Often greyish.
4. Diallage. Diallage— Metalloide,
Schiller-Spar, Bastite, is perhaps the
same ; lamellar, greyish or brownish ;
curved cleavages ; sometimes classed
with Hypersthene. H. = 4. See also
Schiller-Spar.
5. Bionzite. Very similar, but darker
and less fusible. S^e also Hypersthene.
6. Saussurite (which see) is, perhaps,
a variety.
7. Smaragdite is grass-green ; H. 5 ;
G. 3-31.
Many other varieties have been distin
guished.
B., etc. In matrass scarcely changed;
on C most varieties fuse quietly at about
2 (some intumesce somewhat) to a glassy
bead ; with borax and micro, give Fe re-
actions ; scarcely soluble, however, in
micro. ; the light varieties become pinkish
PYROXENE.
QUAETZ.
85
if treated with Co; scarcely affected
by acids, except when in fine powder ; a
long digestion (sometimes partially de-
composes it.
Comp. Anhydrous silicate of Mg, Ca,
and other bases. No analysis of a Bri-
tish specimen is known to the aiithor,
but foreign specimens sometimes yield
about 55 '0 per cent, of silica, 25 '7 of
lime, and 18 "6 of magnesia. With these
proportions the formula might be written
CaSiMgSi or CaSiO3 + MgSiO3 or Si2O2
Cao"Algu".
Loc. a. Augite. Rocks north of Bo-
tallack, and Huel Cock.
b. Bronzite. Coverack Cove, of a dark
brown colour, in serpentine.
c. Diallage. In "'Diallage Rock" at
Coverack Cove, Crousa Downs, G winter,
and many other parts of the t>t. Keverne
district ; the Manacles ; &c.
d. Smaragdite is said to have occurred
at Coverack (J. Garby, Traus. Roy. Geol.
Soc. Corn., vol. vii., p. 76).
Ob*. Pyroxene in its various forms is
a common mineral in crystalline lime-
stones and dolomites, serpentines, vol-
canic rocks, &c. ; it ocours also, but less
abundantly, wi'h granitic rocks and me-
tamorphic schists. The pyroxene of
limestones is mostly white, light green,
or greyish ; that of most other metamor-
phosed rocks although sometimes color-
less, is usually green of various shades,
from pale green to greenish-black : that
of serpentine sometimes occurs in tine
crystals, often of the foliated green kind
called "Diallage;" that of eruptive
rocks is the black, or greenish-black
"Augite."
"Lime is a prominent ingredient in
all the varieties of Pyroxene, while it is
wanting, or nearly so, in some (most?)
of those of Hornblende." "In Pyroxene,
columnar and fine fibrous forms are un-
common ; in Hornblende, exceedingly
common." (Dana, System of Min.,
1868.)
It really seems as if the many varieties
of so-called Pyroxene, Amphibole, Hy-
persthene, &c. are still too little known
to allow of a rational classification. They
sliould, perhaps, form one great group,
only divisible into sub species.
Descloizeaux separates ttionzite "da
Cap Lizard, Cornouailles," and Hypers-
thene from Diallaye and Pyroxene on ac-
count of their c> ystaltoyrafitac and opti-
cal characters.
A tiyles.
MM' = 87° 06' ab = 90° 00'
Ma 133 55 sb 119 44
Mb 136 27 ss 120 31
PYRRHOTITE.
[Pyrrhotine. Magnetic Pyrites.] Hex-
agonal, in prisms, with perfect basal
cleavage, but very rarely crystallized ;
usually massive ; lamellar, granular,
compact or disseminated ; i>rittle ; frac-
ture uneven ; opaque ; lustre metallic ;
bronze yellow, with often a reddish or
brownish tarnish ; streak greenish or
greyish-black; H. 3'5-4'5; G. 4'4-7 ;
sightly magnetic.
B., etc. Jn matrass yields a yellow
sublimate of sulphur ; on C fuse-* at 1
to a grey magnetic globule ; with soda
gives Fe reactions ; soluble in warm
HC1, with evulution of H.2S.
Comp. Anhydrous proto-sulphide of
iron. The following analysis of a Corn-
ish specimen is by Hatchett : —
Iron 63 '5
Sulphur 36'5
Total lOO'O
This agrees almost exactly with the for-
mula FeS, but some specimens seem to.
have an excess of sulphur.
Loc. Botallack ; Levant ; Huel Jane,,
Huel Kind, St. Agnes; "Magnetic p\-
rites has been found at St. Agnes, in
cubic (?) crystals, upwards of an inch in
diameter, and also missive, of- a lamellar
structure, in this and other localities of
the mining districts" (J. Garby); Huel
Maudlin, cleavable and massive ; Huel
Kit church, near Bodmin (massive).
Beeralstone ; Meldon Quarry, ne^ir Oke-
hampton. Found also in Wales, Scotland,.
Ireland, and many foreign localities.
Ubs. It may be distinguished from,
Pyrites by its inferior hardness, from
Chalcopyrite by its colour and blowpipe
reactions, from Pentlandite by its mag-
netism and by the absence of nickel.
Quartz. A family name which conve-
niently includes the following four spe-
cies, or sub-species, viz. : —
1 QUARTZ, or Hyaline Quartz,
2 JASPER,
3 CALCEDONY,
4 OPAL.
These are each described under their re-
spective heads.
Probably a division of the whole family
into (Crystalloid Quartz, including Quartz,
proper and Jasper ; and Colloid Quartz,,
including Calcedony and Opal, would be
the most natural.
Jasper seems to be nothing more than
ordinary massive quartz rendered opaque
by the presence of foreign matter in very
variable proportions. This would hardly
seem to be a sufficient reason for sepa-
rating it, since some well-defined Quartz
86
QUARTZ.
QUAETZ.
crystals (ferruginous) have been analysed
and found to contain as much as 5"0 per
cent, of peroxide of iron.
Calcedony is evidently distinct from
Quartz by its essentially non-crystalline
(colloid) character, but as the purest
varieties have usually a small proportion
of water, are somewhat softer than
Hyaline Quartz, are often somewhat
lighter, and always partially soluble in
solution of caustic potash, it does not
seem clear that it should be separated
from Opal Flint would probably form
a passage to Semi-Opal, and Carnelian. to
Noble Opal.
QUARTZ.
[Rock Crystal; &c.] Hexagonal, in
forms like Figs. 203 to 211, 243, &<•.;
usually in prisms, horizontally striated,
sometimes doubly terminated ; more usu-
ally singly terminated, with the summit
planes very unequally developed ; no
distinct cleavage, but sometimes in
laterally adherent groups, producing a
pseudo cleavage ; parallel or divergent ;
not unfrequently macled ; also massive ;
compact, granular, columnar, fibrous,
cellular, &c.; brittle; fracture conchoi-
dal, uneven, or "rippled" in amethyst ;
transparent to translucent (Jasper is
opaque); lustre vitreous, sub-adaman-
tine, or resinous on fracture ; splendant
to glimmering ; colourless, or yellow,
red, green, brown, purple, black, &c.;
streak white; H. TO; G. 2 "5-2 '8, the
purest varieties 2 '65; frictio-phosphoric.
Far. 1. Rock Crys tal is the colourless
crystallized (typical) variety. Cornish,
Bristol, Irish, and other so-called dia-
monds are rock crystal. The Cornish
Diamonds are often obscured by an
opaque ferruginous layer when first ob-
tained.
2. A methyst is a variety with a pecu-
liar "rippled" fracture, which possesses
Borne remarkable optical properties. It
is usually of a more or less deep violet or
purple tint ; in some instances this has
been proved to be due to a minute trace
of oxide of manganese. "Heintz, how-
ever, on analysing a very deep purple
specimen from the Brazils, obtained in
addition to silica, 0'0187 protoxide of
iron, 0.6236 lime, 0'0133 magnesia, and
0'0418 soda, whence he infers that the
colour is due to a compound of iron and
soda." (Bristow's Gloss. Min. p. 13.)
3. Citrine or False Topaz is a variety
tinted of a clear yellow colour with oxide
of iron.
4. ferruginous Quartz is the same,
but duller, and with less lustre.
5. Cairngorm or Smoky Quartz is a
clear transparent variety having a rich
smoky-brown tint.
6. Morion is the same, but so deeply
tinted as to appear almost black.
7. Hose Quartz, as the name implies,
is of a rosy tint, but usually very pale,
and often full of cracks. «
8. Milk Quartz is bluish-white and
nearly opaque.
9. Greasy Quartz is compact and mas-
sive, and so-called because of the
" greasy" lustre.
10. Sugary Quartz is granular, like
loaf-sugar.
11. Cellular Quartz or Floatxtone con-
sists of a multitude of small cells, filled
with air, and surrounded with very thin
films of quartz It is so light as to float
on water. Specimens from Pednanrirea
and other mines would seem to indicate
that it is a pseudomorphous deposit on
Fluor Spar, which has now disappeared.
12. Fibrous Q uartz or Cro«s-course Spar
is made up of a multitude of imperfect
prisms laid side by side ; the free termi-
nations often present crystalline planes.
13. Pra*e is a dark leek-green variety,
which occurs massive only. The colour
is said to be caused by an admixture of
Amphibole.
14. Babel Quartz is a name given to
peculiarly formed crystals, like Fig. 209.
15. Hacked Quartz is a crystalline
variety of Quartz, with markings on its
sides as if "chopped" or "hacked,"
arising from former partially imbedded
crystals.
16. Stajactitic Quartz "consists of
straight stalactites, several inches in
length, composed of an aggregation of
crystals diverging from a centre (of cal-
cedony?), the pyramid of the crystal ap-
pearing on the surface." (Phillips's
Mineralogy, 1823, p. 7.)
17. Haytorite is rather Calcedony than
I Quartz. It occurs in pale brownish crys-
I tals, having the form of Datholite, at
i Haytor and North Koskear.
B., etc. In matrass no change; on C
alone, infusible; with soda or borax fuses
with much effervescence to a clear glass ;
with micro, retains its form ; insoluble
I in HC1, HNO3, or H2SO4 ; soluble in
HF.
Comp. Anhydrous silica. With sili-
con 48 '94 perjcent. and oxygen 51 '96 per
cent., the formula will be SiO2. It often
contains smalt quantities of various me-
tallic oxides. Some very rare instances of
crystals of ferruginous quartz from Bo-
tallack have yielded as much as 5 per
cent of peroxide of iron.
QUARTZ.
QUARTZ.
87
Loc. a. Rock Crystal. CORNWALL. —
Fine specimens have occurred at Botal-
lack, Boscawen Cliffs, Balleswidden,
Spearn Moor, Trewellard, Huel Diamond,
and other localities in St. Just ; at St.
Michael's Mount; Huel Alfred, Phillack
(rhombohedrons); at HerlandaridTrevas-
cus, in Gwinear ; at the Lizard, in ser-
pentine ; at Swanpool and Mainporth,
near Falmouth (the primary rhombohe-
dron, more or less perfect, and other
forms, in elvan); at Dolcoath (Fig. 243
is a curious example from here); North
Roskear, and other mines in Camborne ; at
East HuelCrofty, East Pool, and the Cam
Brea mines in Illogan (Fig, 208, 211, &c.);
Huel Buller, Huel Sparnon, and other
mines in Redruth ; the Consolidated and
other mines in G wennap (primary rhombo-
hedrons and other forms); at Perranzabu-
loe (double pyramid without prism); St.
Ewe, in slate ; near Caerhayes (primary
rhombohedron); at Penlane and Trelow-
eth, in St. Columb (with pinite in elvan);
East Crinnis, St. Blazey; Restormel,
Lostwitbiel ; Huel Mary Ann, Menhe-
niot ; at the Delabole Slate Quarries, St.
Teath; Tintagel. "They occur in nests
in the slate-stone, imbedded in a yellow-
ish-white clay, like mud, and sometimes
as black as wet soot. The whitish-yellow
fluid is decomposed adularia, many per-
fect crystals of which are found adhering
to the quartz. The black matter is de-
composed slate stone." (Man. of Min.,
Truro, 1825, p. 187.)
DEVON. — Roborough Downs, Buckland
Monachorum (in fine double pyramids);
Huel Betsy, near Tavistock ; near Oke-
hampton ; Gidleigh, near Moretonhamp-
Btead; North Bovey; Combemartin, near
Ilfracombe ; Lundy Island, &o.
Foreign localities are too numerous to
mention.
b. Amethyst. Botallack, Huel Bellon,
Huel Cock, Bosavern, Levant, Nangisel
Cove, Roscommon Cliff, and other St.
Just localities ; Huel Uny ; Copper Hill ; j
Pednandrea; Huel Tolgus ; East Pool,
with pale yellow chalybite ; Great Hewas
United, St. Me wan; Polgooth; St. Cleer;
St. Ewe, &c., finely crystallized in
prisms ; Copper Hill, near Okehampton.
c. Citrine. Botallack; St. Michael's
Mount ; Cam Brea ; Restormel.
d. Ferruginous Quartz. Botallack ;
Marazion ; Cam Brea ; Dolcoath ; Res-
tormel ; St. Agnes ; North Bovey, in
large opaque crystals (like Fig. 210).
e. Cainujorm. Trewellard ; North
Roskear ; Huel Buller ; St. Cleer ; St.
Ewe.
f. Morion. Little Bounds, formerly,
in brilliant double pyramids ; Huel
Ruby ; Fowey,
g. Rose Quartz. St. Michael's Mount,
in small crystals, with cassiterite ; Huel
Bucketts, massive and crystallized, and
usually full of cracks.
h. Mi'ky Quartz. North Roskear,
massive, bluish; Pednandrea; United
Mines, Gwennap ; Great Huel Vor,
Breage.
i. Sugary Quartz. St. Agnes; Mount
Hawke ; &c.
j. FloaUtone. Huel Alfred ; Cardrew
Downs ; Pednandrea ; Relistian, &c.
k. Fibrous Qu-i.rtz. Huel Virgin ;
Tolcarne; Cardrew Downs; St. Agues;
Relistian.
1. Prase. Huel Bellon ; North Ros-
kear, dark green and massive.
m. Hacked Quartz. Huel Trelawny;
East Pool.
n. Babel Quartz. Tamar Mines.
o. Stalactitic Quartz. Botallack, and
Huel Alfred, formerly ; more recently at
Pednandrea.
Ordinary massive Quartz is common in
almost every mine and quarry, while a
large proportion of granite consists of
imperfect crystals of the same mineral.
Many specimens of Quartz from differ-
ent localities contain enclosed crystals of
schoii and other minerals. A few loca-
lities are appended : —
Enclosing — • Locality.
Rock Crystal, Cassiterite, Huel Diamond.
Pyrites, „
Chalcopyrite, „
Chlorite, Dolcoath.
Hematite, Botallack.
„ Dolcoath.
„ East Pool.
,, Restormel.
Amethyst, Schorl, Eoscommon Cliff.
Chlorite, Botallack.
Quartz, Liquids, Utd. Mines (octa),
„ „ Virtu. Lady (cubes)
„ „ Beeralstone(cubes)
For the many Quartz pseudomorpha
see list of Pseudomorphs.
(/&.«. The Quartz from copper lodes is
said to be rarely transparent. Long nar-
row prisms are said to be most common
in tin lodes, and almost unknown in lodes
containing lead. There is often a pecu-
liar brilliancy observable about the
quartz from lead lodes, which may be
well observed in specimens from West
Chiverton, and Huel Rose and Huel
Penrose, Sithney. Quartz may be dis-
tinguished from other minerals some-
what resembliiig it by its degree of hard-
ness, crystalline form, brittleness, want
of cleavage, and other characters.
A ngles.
RR =
Rz
Rb
bb
94°
133
158
120
15'
44
31
00
bs =
bx
bz
142°
167
141
172
00'
59
47
31
88 RADIATED PYRITES.
RHOMBOID.
R.
See Hematite.
Radiated Pyritea. See Marcasite and
Pyrites.
Radiated Zeolite. See Stilbite.
Red Chalk. See Hematite.
Red Cobalt Ochre. See Erythrite.
Reil Copper Ore. See Cuprite.
Red Hematite.
Red Iron Ore.
Red Iron Ochre.
Red Iron Ston°.
Red Oxide of Copper. See Cuprite.
Red Oxide of Iron. 1 g H,matite.
Reddle. )
Red Silver Ore. See Pyrargyrite.
Reduced. The conversion of a higher
oxide, sulphide, &c., into a compound
containing a lower proportion of oxygen,
sulphur, &c. , or into the metallic state,
either by driving off the metalloid, or,
more usually, by adding some "flux" or
"reducing agent" to combine there-
with. The blowpipe is often used for
reductions on a small scale. See "Blow-
pipe," par. 5, p. 18.
Reduction. The operation of reducing,
as when copper is obtained from copper
ore, or tin from tin ore, &c.
R^diuthite. See Chalcocite.
Reflected Light. Light reflected from
any surface. When objects are looked
"at," and not looked "through," they
are seen by reflected light. When looked
" through" they are seen by transmitted
light.
Reniform. Kidney-shaped. Having
email irregular rounded prominences like
the surface of a bullock's kidney.
Replaced. See Modified.
Reticulate. Netted. Some specimens
of native copper occur in interlaced
fibres, and are so-called.
RETINITE.
[Retinasphaltum.] Amorphous, in
rounded or irregular lumps; brittle;
fracture imperfect conchoidal, earthy, or
uneven ; translucent to opaque ; lustre
resinous, glistening, or dull; yellow,
yellowish-brown, greenish, reddish, or
dark greyish-brown ; streak lighter than
colour; H. 1-2 '5; G. 1-1 "2.
#., etc. In matrass melts to a clear
fluid at a low temperature ; on C burns
with a bright flame, and fragrant or aro-
matic odour ; insoluble in acids ; partly
soluble in alcohol, leaving an unctuous
residue ; more readily soluble in ether.
Comp.
Carbon 76'86
Hydrogen 875
Oxygen 14'39
Total . ., 100-00
; (J. F. W. Johnston, Phil. Mag. III.,
1 XII., p. 500 1838.)
The composition is a little indicated
in another way as follows : —
a. b.
Resin, Sol. in aloo. 55 '0 ... 59 '32
Bitumen 41'0 ... 27'45
Earthymatter 3'0 ... 13'23
Total 99-0 ... 100-00
a. is by Hatchett, b. by Johnston.
Loc. Bovey Tracey", in irregular no-
dules, in Lignite. Found also in Hano-
ver, with peat, and in the Uuited States.
RHODONITE.
[Siliciferous Oxide of Manganese.]
Oblique; isomorphous with augite
(Broulce), anorthic (Greg and Lettsom) ;
oryst ils very rare ; clea\ ag •* perfect clino-
diagonal ; usually massive ; compact or
granular ; brittle ; fracture flat conchoi-
dal or uneven ; translucent to opaque;
lustre vitreous to pearly ; rose-red to
reddish -brown, or greenish ; sometimes
a dark tarnish from exposure to light ;
streak very light or white ; H. 5-6 ; G.
3-4-3-7-
/?., etc. In matrass slightly darkens ;
on C turns brown, and fuses to a dark
globule with a strong heat ; with borax
gives Mn reactions ; soluble except the
silica in strong HC1 if finely powdered.
Comp. Anhydrous silicate of manga-
nese. With silica 46 '0 percent, and prot-
oxide of manganese 54 '0 per cent, the for-
mula may be written MuSi or MnSiO3 or
SiOMno".
Loc. At a manganese quarry, li mile
south-east of Callington ; Creva Wood,
I near Callington ; Trebartha ? Indian
| Queens? Veryan ? Blackdown, with
; manganite and psilomelane ; Upton
| Pyne. Found also in Germany, Italy,
Sweden, Siberia, and many other foreign
\ localities.
Rhomb. A four-sided plane figure,
. whose sides are equal straight lines, but
i whose angles are not right angles.
Rhomb Spar. See Dolomite.
Rhombic Dodecahedron. A solid
i twelve-sided figure, belonging to the
cubic, syxtem, in which each face is a
; rhomb (Fig. 3).
Rhombohr dral Iron Ore. See Hema-
tite.
Rhombohedral Iron Pyrites. See Pyr-
rhotite.
Rhombohedron. A solid figure, bound-
ed by six equal rhombs. See Fig. 197.
Rhomboid. A plane four-sided figure,
the opposite sides of which only are
equal, and whose angles are not right
angles.
ROOK COEK.
SCHEELITE.
Rock Cork, Taper, Wood, &c. See
Amphibole.
Rock Crystal. See Quartz.
Kock Marrow. See Lithouiarge.
Ruby Silver. See Pyrargyrite.
RUTILE.
Pyramidal ; in small prisms or pyra-
mids, often macled, striated, or uneven,
and having a general resemblance to
crystals of cassiterite (Figs. 61 to 71);
two tolerably perfect cleavages ; often
imbedded or massive ; brittle ; fracture
conchoidal or uneven ; translucent to
opaque ; lustre adamantine or sub-me-
tallic; splendant to glimmering ; brown-
ish, reddish, yellowish, or blackish ;
streak light brown; H. 6 '0-6 '5: G.
4-2-4-8.
B., etc. Like Anatase.
Comp. Titanic anhydride, like Ana-
tase and Brookite.
Loc. It is said to have been found in
the slate quarries of Delabole, in hair
brown threads, imbedded in quartz crys-
tals, or in four or six-sided prisms, lon-
gitudinally striated; and at Tintagel
cliffs, in brilliant prisms, imbedded in
transparent quartz.
8,
Saponite. See Steatite.
SA USSURITE.
Anorthic ? sometimes cleavable in two
directions, making angles of 124° ; tough ;
fracture splintery or uneven ; translucent
to opaque ; lustre glimmering ; greyish-
white, green, red, brown ; streak white ;
H. 5-6; G. 2-7-3-4.
B. , etc. In matrass unchanged ; on C
fuses at 4 to a greyish enamel ; insoluble
in acids except HF.
Comp. Anhydrous silicate of alumina,
lime, and magnesia. The following analy-
sis of a specimen from Coverack, is by
Dr. Thomson : —
Silica 82168
Alumina 5'072
Oxide of iron and manganese 2 "880
Lime 5'520
Magnesia 4'520
Potash . trace
Total 100160
Loc. Coverack and Kynance Coves,
and Gwinter, in the Lizard district, with
diallage rock. It is, perhaps, the so-
called Jade of that neighbourhood.
Scalenohedron. A solid figure, bound-
ed by twelve equal scalene triangles, as in
Fig. 217. It is a common form of calcite
in some districts.
SC A POLITE.
[Meionite. Wernerite.] Pyramidal,
with perfect prismatic cleavage ; often
massive and compact ; brittle ; fracture
conchoidal ; translucent to opaque ;
lustre vitreous, resinous, or pearly on
cleavage ; colourless, white, grey, green-
ish, reddish, brownish ; streak white ;
H. 5-0-5-5; G. 2 "6-2 '8.
B., etc. In matrass unchanged ; on C
melts at 3 to a transparent glass ; treated
with Co turns blue ; soluble with effer-
vescence in borax or micro. ; decomposed,
in powder, by HC1.
Gomp. Anhydrous silicate of alumina
and lime. No analysis of a British spe-
cimen is known to the author, but foreign
specimens contain from 37 to 54 per cent,
of silica, 25 to 35 per cent, of alumina,
and 9 to 24 per cent, of lime.
Loc. A little south of the village of
Chagford, in a narrow vein of granite,
with felspar, schorl, quartz crystals, and
calcedouy. It was found in the year
1868, by Mr. G. W. Ormerod, F.G.S.,
and occurred in a mass as large as the
palm of the hand (Rep. Dev. Assoc,, vol.
III., p. 80, 1869).
SCHEELITE.
[Tungstate of Lime.] Pyramidal; in
attached or imbedded four-sided prisms,
usually more or less modified (Figs. 86,
87, 88); with some faces striated,
rough, or curved; sometimes reniform,
columnar, or massive ; brittle ; fracture
conchoidal or uneven ; translucent to
opaque ; lustre vitreous, resinous, or
adamantine; colourless, greyish, yellow-
ish, reddish, brown, or green ; streak
white or slightly tinged; EL 4-4 "5; G.
5-9-6-2.
B. , etc. In matrass no change, or de-
crepitates only ; on C decrepitates and
becomes opaque ; fuses at 4, or infusible ;
soluble in HC1 or HNO3, except yel-
low tungstic anhydride, which sepa-
rates ; soluble, except the lime, in KHO ;
yellow tungstic anhydride is precipitated
on addition of HC1 or HNO3.
Comp. Anhydrous tungstate of lime.
A specimen from Pengelly Croft yielded
to Klaproth the following results, viz.: —
Lime 18'70
Tungstic anhydride 75 '25
Silica 1-50
Peroxide of iron 1"25
Peroxide of manganese 0 "75
Total 97-45
With tungstic anhydride 81 '0 per ceiit.
90
SCHEEL OEE.
SCOKOBITE.
and liine 19 per cent, the formula may
be written CaW or CaWO4 or W02Cao".
Loc. Pengelley Croft, Breage, former-
ly, in a tin lode ; Huel Maudlin ; Huel
Friendship, in fine octahedrons of a rich
yellow colour, imbedded in chlorite, and
occasionally associated with wolfram —
the crystals formerly met with at this
locality were sometimes 1£ inch long. It
is found also in many foreign locali-
ties.
Obs. Like other ores of tungsten,
Scheelite is characterised by a high sp.
gr. It was in this mineral that tungstic
anhydride (acid) and tungsten were first
discovered by Scheele.
Anqles.
PP = 100° 40'
PF 129 02
Pe 140 10
Px 151 34
Scheel Ore. See Wolfram.
ee = 108° 12'
ee' 112 02
e y 171 30
SCHILLER SPAR.
[Diallage-metalloide. Bastite .] Oblique,
or anorthic ; one very perfect cleav-
age ; brittle ; fractuie uneven or splin-
tery; translucent to opaque; lustre
pearly, sub-adamantine, or sub-metallic ;
greenish, yellowish, or brownish ; streak
nearly white ; H. 3 '5-4; G. 2 '6-2 '8.
/?., etc. In matrass yields water,
which has often an alkaline reaction ; on
C becomes brown and often magnetic ;
fusible at about 4 ; with borax gives re-
actions for iron or chromium ; decom-
posed by H2SO4 ; less completely by
HCL
Coinp. Hydrated silicate of magnesia
and other bases. No analysis of a Bri-
tish specimen is known to the author,
but foreign specimens contain about 43 0
per cent, of silica, 26 '0 per cent, of mag-
nesia, 12 '0 per cent, of iron, and 12 '0
per cent, of water.
Loc. Coverack, Gwinter, Kildown
near Cadgwith, Kennick Sands, and
other parts of the Lizard district, im-
bedded in a serpentinous rock.
Obs. Its composition and peculiar
properties, need special investigation. It
should, perhaps, be regarded as a sub-
species of Pyroxene. Perhaps several
distinct minerals have been described
under this name.
Schist. An imperfectly foliated rock,
which splits up into thin irregu'ar plates.
The Cornish and Devonshire killas is
Schist. Mica-Schist occurs in the neigh-
bourhood of St. Ives and other places.
Schorl. See Tourmaline.
SCHROTTERITE.
Amorphous ; compact ; massive ; brit-
tle ; translucent to nearly transparent ;
lustre resinous or greasy ; white, more
often greenish, yellowish, or spotted with
brown ; streak white ; H. 3-3 "5; G. T9-
21.
B. . etc. In matrass yields much water ;
on C becomes a white opaque infusible
mass ; with Co turns a fine blue colour ;
decomposed by HC1.
Comp. Hydrated silicate of alumina,
like Allophane, but with less silica.
Dana gives about 12 per cent, of silica
for Schrotterite, and 20 '0 per cent, for
Allophane.
Loc. Cornwall (Dana). See remarks
on Allophane, p. 3.
SCORODITE.
[Martial Arseniate of Copper.] Rhom-
bic ; in globular groups of small crystals,
shewing faces of the prism and pyramid
(Fig. 244); perfect cleavage parallel to
M ; often drusy on other minerals ; rarely
compact ; brittle ; fracture uneven ; se-
mi-transparent to translucent on edges
only ; lustre vitreous, resinous, or ada-
mantine ; streak white or nearly so ; pale
green, bluish, brownish ; dichroic ; H.
3-5-4; G. 31-33.
J3., etc. In matrass gives off water and
turns yellowish ; with a strong heat
yields a white crystalline sublimate ; on
C melts to a grey magnetic slag with
metallic lustre ; gives off strong alliaceous
fumes ; soluble in HC1 ; partly soluble
in KHO, the residue turning brown.
Comp. Hydrated arseniate of iron.
A Cornish specimen yielded the follow-
ing results to Damour : —
Arsenic anhydride 51 "06
Peroxide of iron 32 '74
Water 15'68
Total 99-48
With arsenic anhydride 49 "8 per cent.,
peroxide of iron 347 per cent., and water
15 "5 per cent, the formula may be written
Fe2As24H2 or FeAsO4 + 2H2O or As2O4
Feo"2 + 4OH2.
Loc. Huel Muttrell, Huel Unity, Huel
Gorland, Carharrack, and Tincroft (Phil-
lips's Mineralogy, 1823, p. -321); recently
in minute pale greenish blue crystals, on
calcedony, from Pednandrea ; St. Aus-
tell, lining cavities ("vugs'r)in tin lodes,
in pale bluish-green radiating groups ;
Crinnis. Found also in France, Ger-
many, Brazil, and other foreign localities.
Obs. It may be readily distinguished
from the arseniates of copper, some of
SEOTILE.
SERPENTINE.
91
which it much resembles, and with which
it is often associated, by its blowpipe
re-actions.
Angles.
M M' = 98° 02' M r = 145° 29'
Ma 130 59 r r' 114 34
Mb 130 09
Sectile. Those minerals are termed
sectile from which when cut with a knife
the fragments do not fly away in powder.
They are midway between brittle and
malleable. Ex. Chalcocite.
Selenite. See Gypsum.
SENARMONTITE.
Cubic ; usually in octahedrons, like Fig.
1, more or less modified ; brittle ; frac-
ture uneven or lamellar ; transparent to
translucent ; lustre resinous to adaman-
tine ; colourless ; streak white ; H. less
than 3; G. 5 '2-5 '3.
B., etc. In matrass sublimes com-
pletely with a strong heat, depositing a
white sublimate ; on C volatilizes, and
deposits a white crystalline coating ; in
K, F is reduced to a brittle metallic bead,
especially if mixed with soda or cyanide
of potassium; tinges the flame green ; solu-
ble in Aqua Regia, but precipitated from
the solution on addition of much water ;
with H2S yields an orange red precipi-
tate.
Comp. Anhydrous oxide of antimony.
Sb2 or Sb2O3 with, when pure, antimony
84 '3 per cent, and oxygen 15 '7 per cent.
Loc. Some of the antimony mines in
the east of the county, on Jamesonite,
with Bleinierite. It was first observed
by Mr. Davis, of the British Museum,
who found it in opaque regular octahe-
drons in a cavity of Jamesonite, accom-
panied with Bleinierite and minute crys-
tals of Cerussite, but the author has since
found it on specimens of his own.
Obs. It is best distinguished from
Valentinite by its crystalline form.
SERPENTINE.
[Ophiolite. Ophite; &c.] Amorphous;
massive; fibrous, foliated, granular, or
compact ; sectile ; tough ; fracture con-
choidal, uneven, or splintery; translu-
cent to nearly opaque ; lustre resinous,
vitreous, glimmering, or dull ; various
•shades of green, red, brown, yellow,
or nearly white ; often mottled, and con-
taining disseminated crystals of Bron-
zite or Diallage, and particles of chro-
mite or other minerals ; streak white, or
slightly tinged as the colour ; H. 2*5-4
(5'5 Bowenite); G. 2 '4-2 '6.
Var. The following are the chief of
those described by Dana and others,
some are, perhaps, distinct species : —
1. MASSIVE:—
a. Noble or Precious Serpentine has a
rich oil-green colour and considerable
lustre. It is translucent, even in thick
pieces. H. 2 '5 to 3'0.
b. Retinalite is honey-yellow to light
oil-greea ; H. 3'5 ; G. 2 "47 to 2 '52.
c. Common Serpentine is sub-translu-
ceut, or nearly opaque ; the colours are
often dull red or brown ; H. 4'0.
d. Porcellaphite is earthy; very soft
when first obtained ; smooth porcel-
lanous fracture ; H. 3'5 ; G. 2 '48.
e. Bowenite. Apple-green to green-
ish-white ; fine granular structure ; H.
5'5-G; G. 2-59-279.
2. LAMELLAR : —
a. Antigorite. Thin, easily separable
laminae ; translucent or semi-transpa-
rent ; smooth, but not unctuous ; H.
2 '5. It will sometimes cleave into rhom-
bic prisms.
b. Williamsite. Apple-green > H. 4 '5;
G. 2-59-2-64.
3. FOLIATED :—
a. Maumolite. Thin folise, brittle ;
easily separable, or passing into an almost
compact variety ; lustre pearly ; green-
ish-white or bluish ; G. 2 41.
b. Thermophyllite. Small scaly ag-
gregations ; light brown, yellow, or sil-
very-white; lustre of cleavage pearly;
H. 2-5; G. 261.
4. FIBROUS:—
a. Picrolite. Almost columnar; not
flexible ; not often easily separable ; long
splintery fracture ; dark green, greenish-
giey, or brown. Metaxite is very similar,
but separable into brittle greenish-while
columns.
b. Chrysotile occurs in easily separable
flexible fibres of a greenish- white, yel-
low, or brownish color, and silky or sub-
metallic lustre ; G. 2 "2. It includes
much of the so-called asbestos of ser-
pentine rocks.
Very many other varieties are de-
scribed, mostly from their external char-
acter alone. Some writers include Schil-
ler-Spar or Bastite with Serpentine.
B., etc. In matrass always gives off
water, and usually darkens ; on C turns
white ; fuses at 4, or is infusible ; with
Co often indicates Mg; with borax or
micro, yields reactions for Fe, Ni, or Cr ;
decomposed by HC1 or H2SO4, leaving
powdery or slimy silica.
Comp. Hydrated silicate of magnesia
and various other bases, with from 11 '0
i to 16 -0 per cent, of water, 39 '0 to 44 '0
92
SEBPENTINE.
SILICATES.
per cent, of silica, and 30 '0 to 44 '0 per
cent, of magnesia. Of the following
analyses a. and b. are of dark green ser-
pentine from the Lizard district. "The
specimen is of a very dark green colour,
in places verging upon black ; it is thickly
spotted with red, and has a coarsely gra-
nular structure. . . . massive, with-
out any indication of foliation." "The
microscope shows this rock to consist of
a crypto-crystalline base, spotted by
oxide of iron, &c., and enclosing indis-
tinct green or yellowish-brown crystalline
forms, pseudomorphs after pyroxene?"
(J. A. Phillips, Phil. Mag., Feb., 1871):—
a. b.
Silica 38-86 ... 38'58
Alumina 2'95 ... 3'06
Ferric oxide 1'86 ... T95
Ferrous oxide 5 '04 ... 510
Chromic oxide 0 '08 ... 0'08
Oxide of nickel 0'28 ... 0'30
Oxide of manganese trace ... trace
Lime trace ... trace
Magnesia 34'61 ... 34'52
Potash 033 ... 0'30
Soda 077 ... 076
Water 15'52 ... 15'52
Total 10030 ». 99-97
Sp. gr 2-59 ... 2-59
With 43-7 per cent, of silica, 43 '3 per
cent, of magnesia, and 13 "0 per cent, of
water the formula may be written
3Mg2Si2H2 or 2MgSiO3 + MgH2O2 + H2O
orSi2Mgo"gHo2 + OH2.
A dark green serpentinous rock from
Clickor Tor yielded to the same che-
mist : —
a. b.
Silica 36-60 ... 38'80
Titanic acid trace ... trace
Phosphoric acid ... trace ... trace
Alumina 17 '58 ... 17'CO
Ferric oxide 141)8 ... 1510
Ferrous oxide 4 "52 ... 4 '50
Chromic oxide 014... 014
Oxide of manganese trace . . . trace
Lime 5'04 ... 4'92
Magnesia 5'97 ... 6 '04
Potash trace ... trace
Soda 0-84 ... 0-85
Water 10 '66 ... 10'46
Total 98-43 ... 98'41
Sp. gr 277 ... 277
Mr. Phillips observes : — " The micro-
scope shews this to be a highly metamor-
phosed rock, consisting of an amorphous
matrix porphyri tic ally enclosing yellow-
ish-brown or green patches with indis-
tinct crystalline forms, which are evi-
dently pseudomorphs. There are also '
many black grains of magnetite, and
crystals of some pyroxenic minei-al— pro-
bably Schiller-spar or diallage (ibid).
Loc. Cadgwith, Kynance, Goonhilly
Downs, Coverack, and many other lo-
calities in the Lizard district yield good
specimens ; Duporth, west of Charles-
town ; Tregarthen; Gorran ; St. Cleer
and Clickor Tor, near Liskeard ; Polla-
phant, near Launceston ; &c. It occurs
also in Anglesea, Scotland, Ireland, and
many foreign localities.
Obs. Serpentine should, perhaps, be
regarded rather as a rock than a mineral.
It often contains veins of steatite or cal-
cite, and its joints often contain native
copper. Crystals of Diallage or Bron-
zite, and minute particles of Chromite,
Magnetite, Pyrites, and other minerals
are often disseminated through it.
Siderite. See Chalybite.
Silicates. Compounds of silica with
various metallic oxides are so called.
They are very numerous, and often very
difficult to distinguish from each other
by any means short of chemical analysis.
Dana divides the silicates into groups
according to the oxygen ratio for the
" bases " and silica, into —
Base. Silica.
1. Uni-silicates =11
2. Bi-silicates =12
3. Sub-silicates = 1 i J, f, &o.
In the blowpipe or pyrognostic exami-
nation of silicates the chief points to
be noted are : —
1. Whether moisture is given off on
heating in matrass (hydrated silicates).
2. Whether the moisture has an acid
reaction (Fluorine) or alkaline (probably
some altered mineral). For fluorine, test
specially with "Brazil- wood paper," and
also observe whether the inside of the
tube is roughened, &c.
3. Whether the specimen is fusible
when heated on charcoal, and in what
degree, or remains infusible. (If it be-
comes magnetic, iron is indicated; such
silicates are usually fusible).
4. Those which leave a white or nearly
white residue after heating on charcoal,
or in forceps, may be treated with Co.
for detection especially of alumina and
magnesia. If a blue colour is produced,
alumina is indicated ; if .pink or red,
magnesia ; if green, zinc.
5. When the specimen is neither colour-
less nor nearly white after strong heat-
ing, it should be tested for metallic
oxides by means of borax or micro.
6. Silicates of copper (Chrysocolla and
Dioptase) will yield a bead of copper if
treated with soda.
SILICATE OF TIN.
SMALTITE.
93
7. Sulphur may be detected in sili-
cates by fusion with pure soda, after
which the moistened assay is to be laid
upon a polished plate of silver, or sil-
ver coin, when a dark spot will be pro-
duced if sulphur is present.
8. In forceps observe whether the tip
of the OF is coloured (Soda, Potash,
Lithia, Baryta, Strontia, &c.)
9. For fusibility try both OF and RF.
Many silicates which are infusible_ in
OF are fusible in RF by the peroxides
changing to protoxides.
10. Many silicates are soluble in HC1
if finely powdered, except a quantity,
more or less, of silica, which separates
as a gelatinous mass or slimy powder.
11. Nearly all silicates effervesce when
heated with soda. Most are freely solu-
ble in borax, but leave a skeleton of silica
if heated with micro. Upwards of 40 of
the Cornish and Devonshire minerals are
silicates. A few, such as Orthoclase and
Chlorite, are very common ; but very
many, as Topaz, Beryl, Stilbite, &c., are
extremely rare.
Silicate of Manganese. See Rhodonite.
Silicate of Tin. A massive and crys-
tallized pseudomorph after Quartz, from
Huel Primrose, St, Agnes (J. Garby,
Trans. R. G. S. 0., vol VII., p. 85).
Siliceous Oxide of Copper. "Has been
found at South Basset, imbedded in gra-
nite close to the vein, or in a quartzose
rock occurring in the vein. It is black,
with a flat coiichoidal fracture, very much
resembling flint, and of equal hardness.
Before the blowpipe a button of pure
copper is, without much difficulty, pro-
duced, leaving a siliceous skeleton of great
whiteness." (J. Garby, Trans. R. G. S. C.,
vol. VII., p. 89.) What mineral is here
referred to it is difficult to say, as the
characters set down do not agree with
those of any of the recognised Cornish
minerals.
SILVER.
[Native Silver.] Cubic; sometimes
in cubes or octahedrons variously modi-
fied (Figs. 1, 2, 8, 9, 10, 11, &c.); often
macled ; more usually arborescent, fili-
form, or reticulate ; sometimes massive;
malleable ; fracture hackly ; opaque ;
lustre metallic; silver-white, but often
covered with a yellow, brown, or black
tarnish ; streak light and shining ; H.
2'5-S-O; G. 101-11.
B., etc. In matrass no change ; on C
fuses readily to a very bright white me-
tallic bead, depositing a dark red coating
on the charcoal ; insoluble in HC1 ; solu-
ble in HNO3 ; the addition of HC1 re-pre-
cipitates it as a white curdy chloride,
which is soluble in ammonia.
Camp. The purest specimens almost
pure silver. No analysis of a British
specimen is known to the author.
LOG. Fine specimens were formerly
obtained, associated with other silver
ores, at Levant ; Huel Herland, Gwin-
ear, in a soft rock ; Huel Alfred and
Huel Ann, Phillack ; West Huel Dar-
lington : Dolcoath ; North Dolcoath ;
Huel Basset ; Huel Mexico ; Huel Gold-
en Consols ; Great Retallack ; Crinnis ;
Huel Ludcott, filiform, with stephanite,
recently ; Fowey Consols ; Holmbush ;
Huel Duchy ; Huel St. Vincent ; Huel
Brothers ; Willsworthy Mine, near Ta-
vistock, with erythrite and chalcopy-
rite ; Combemartin, in small filaments
with galena. It occurs in most foreign
localities of silver ores.
Obs. It may be readily distinguished
from all other minerals by the reactions
given above.
A ngles.
oo = 109° 28' a a 90° 00'
o a 125 16 &c.
Silver Black, Silver Glance, Silver
Mulm. See Argentite.
Silver White Cobalt. See Cobaltite.
Slate Spar. See Calcite (Schiefer-Spar).
SMALTITE.
[Smaltine. Tin-white Cobalt. Arseni-
cal Cobalt.] Cubic; in octahedrons or
cubes variously modified (Figs. 1, 2, 8,
16, 18, &c.); sometimes macled ; also re-
niform, botryoidal, arborescent, reticu-
late, disseminated, or massive; brittle;
fracture uneven ; opaque ; lustre metal-
lic ; splendant to glimmering, or dull ;
tin-white to steel-grey; often a dark
grey or iridescent tarnish ; streak black,
or very dark grey; H. 5 '5-6; G. 6 '4-77;
yields an alliaceous odour when broken.
Far. Smaltite is the pure cobaltic
variety; G. 6 '3-6 '6.
Chloanthite is a variety in which the
Co is largely replaced by Ni ; G. 7-7 '7.
It is often described as a distinct species.
B. , etc. In matrass gives a white crys-
talline sublimate ; on C fuses atl to a grey
brittle bead of metallic appearance;
gives off an alliaceous odour, and depo-
sits a white coating on the charcoal ;
with borax or micro, yields a deep blue
bead in both flames ; soluble except ar-
senic in HNO3, forming a pink (Smal-
tite) or green (Chloanthite) solution.
Comp. Anhydrous arsenide of cobalt.
No analysis of a British specimen is
known to the author. With cobalt =
28'23per cent, and arsenic = 7177 per
cent, the formula may be CoAs2.
94
SMARAGD.
SPECIFIC GRAVITY.
Loc. Botallack (qy. cobaltite); Wher- ,
ry Mine ; Huel Herland ; Dudman's ]
Mine, Illogan ; Roskrow United, Ponsa- j
nooth ; Huel Sparnon, ou quartz, arbo- ;
rescent and reticulated ; a solid mass of
cobalt ore, probably smaltite, was raised i
in Huel Sparnon about the year 1820, I
which weighed 1,333 Ibs. (Man. of Min.
Truro, 1825, p. 52); East Pool, recently,
massive ; Pednandrea ; Dolcoath ; St. j
Austell Consols ; Polgooth ; Huel Trugoe, j
near St. Columb Major; Huel Huckwor- :
thy, Sampford Spiney ; &c. It is also i
found in considerable quantities in Ger-
many and other foreign localities.
Obs. It may be best distinguished j
from cobaltite by the grey colour of the
crystals, or of a fresh fracture, the ab- ;
sence of distinct cleavage, and the ab- j
sence or small proportion of sulphur.
Angles.
oo = 109° 28' a a = 90° 00'
ao 125 16 ad 144 44
&c. Mostly the same as Pyrites.
Smaragd. Smaragdus. See Beryl.
Smaragdite. A grass -green variety of
pyroxene. Said to have been found at
Coverack (J. Garby, Trans. K G. S. C.,
vol. VII. , p. 76).
Smell. A character of but little im-
portance in determinative mineralogy.
Chrysocolla may often be distinguished
from malachite by its earthy smell when
breathed upon. See also Odour.
SMECTITE.
[Fuller's Earth.] Amorphous; mas-
sive ; sectile ; opaque ; glimmering or
dull ; white, grey, green, or brown ;
streak white, shining ; xinctuous ; non-
adherent ; softens if placed in water ;
very soft; G. T2-21.
£., etc. In matrass gives off much
water; on C infusible (dark varieties
fusible); decomposed by HC1.
Comp. Hydrated silicate of alumina,
magnesia, iron, lime, &c., of very uncer-
tain composition. Rather a rock thau a
mineral.
Loc. Carn Brea, in a copper lode?
(J. Garby, Trans. K. G. S. C., vol. VII.,
p. 76). A similar mineral mass was
found at Huel Penrose, Sithney, a few
years ago.
Sooty Silver Ore. See Argentite (Sil-
ver Black).
Solubility. A character of very general
application and much importance in the
discrimination of minerals. A few mi-
nerals are soluble, more or less readily,
in water. These may be at once known
by their possessing a distinct taste.
To ascertain the solubility of a miner-
al, a little of its powder should be placed
in a test-tube and treated with a few
drops of the solvent. For general analy-
sis, substances which have not a metallic
appearance should be treated with vari-
ous solvents in the following order until
the proper solvent is found.
1. Water.
2. Dilute hydrochloric acid.
3. Strong hydrochloric acid ; warmed
if necessary.
4. Dilute nitric acid.
5. Strong nitric acid ; warmed if ne-
cessary.
6 Aqua Regia,
7. Dilute sulphuric acid.
8. Strong sulphuric acid.
In some cases special solvents, such as
caustic potash, caustic soda, ammonia,
hydrofluoric acid, &c , may be used. A
watch-glass is, for very minute quanti-
ties, sometimes more convenient than a
test-tube.
To ascertain whether any portion of
the substance is dissolved in cases where
it is not freely soluble, a drop of the sol-
vent should be evaporated to dryness on
clean glass, or platinum foil, when, if there
be any fixed residue, it will be evidence
of a certain amount of solution, as these
solvents are all volatilized completely
by heat : unless, indeed, they be impure.
In the case of substances of metallic
appearance much time may often be
saved by using nitric acid — dilute or
strong — before the other solvents.
Any eflervescence, peculiar odour,
change of colour, or appearance should be
carefully noted. Any undissolved or al-
tered insoluble residue must be carefully
examined by the blowpipe and other
means.
Many sulphides, arsenides, or silicates
leave residues which are easily recog-
nised by their appearance or by a few
simple tests.
Solvents. See Solubility.
Spar. A Cornish term for Quartz.
The true spars are such minerals as Cal-
cite, Dolomite, Chalybite, Fluor Spar,
Barytes, Celestite, &c.
Sparable Tin. See Cassiterite.
Sparry Iron Ore, Spathose Iron. See
Chalybite.
Spear Pyrites. See Marcasite.
Specific Gravity. This term is used to
express the weight of a substance com-
pared with some other substance. In
mineralogy distilled water at the tem-
perature of 60° F. or 15 '55 C. or some-
times 4° C. is taken as the standard.
Thus the sp. gr. of water is said to be 1 ;
that of silver about 10.^ ; meaning that
silver is about 10^ times heavier than
an equal bulk of water.
SPECIFIC GKAVITY.
STALACTITES.
95
The specimen to be examined should
be free from foreign matter, from disin-
tegration, or decay (unless it is the sp.
gr. of such a specimen which is especially
wanted), and should contain no cavities;
when these are suspected the mineral
should be powdered.
The following methods will suffice for
most minerals, the first for such as are
in compact masses, the second for small
fragments or fine powder: —
1st Method :—
a. "Weigh the fragment as carefully as
possible in an ordinary pair of scales.
b. Suspend it by a horse-hair from be-
low the scale-pan, let it dip under the
surface of water contained in any con-
venient vessel, and again weigh it. It
will be found that fewer weights will be
sufficient to balance it.
c. Substract the weight indicated in
b. from that in a. ; the difference will be
the weight of a quantity of water equal
in bulk to the specimen.
d. Divide the weight a. by the dif-
ference, c. ; the quotient will be the
specific gravity.
Example 1 — A specimen of white cal-
cedony, from Huel Kitty, St. Agnes : —
a. Weight in air 431
b. Weight in water 27'2
c. Difference 15'9
431 -T-15'9 = 271, the sp. gr. of the
specimen.
Example 2 — Green fluor, from Gwen-
nap : —
a. Weight in air 135'3
b. Weight in water 92'0
c. Difference 43'3
135-3
= 3 "125, the sp. gr. of the specimen.
43-5
2nd Method :—
Procure a small specific gravity bottle,
a light glass bottle with a mark on the
neck ; or, better, a stopper perforated
with a fine hole.
a. Fill it with water, insert the stop-
per, and wipe it dry. Make a counter-
poise the exact weight of the bottle so
filled.
b. Weigh off any convenient quantity
of the substance to be examined, such
that it may be afterwards introduced into
the bottle.
c. Put the weighed fragments carefully
into the bottle, taking care that none be
lost. Of course, as the bottle was pre-
viously full of water, some will now run
out. Having again inserted the stopper
and wiped the bottle, it will be found
that the counterpoise, together with a
smaller number of weights than those
mentioned in b., will be sufficient to ba-
lance it ; the difference will be the weight
of the displaced water, i.e., of a bulk of
water equal to the specimen.
d. Divide the weight of mineral in b
by the difference ; the result will be the
sp. gr.
Example 3 — Fine sand from Marazion.
301 grains were carefully weighed out.
They were then introduced into a spe-
cific gravity bottle ; counterpoised as
described ; when it was found that 185
grains were sufficient to produce equili-
brium. Then the weight of mineral =
301 grains ; weight when placed in bottle
= 185 grains. Difference, or weight of
an equal bulk of water — 116 grains.
Then 301 -^ 116 = 2'6 the sp. gr. re-
quired.
Specular Iron. See Hematite.
Sphene. See Titariite.
Sphenoid. A solid figure resembling
a tetrahedron, but the sides of which are
not equilateral triangles. The hemihe-
dral forms of the tetragonal, rhombic,
and oblique pyramids are called sphe-
noids.
The tetragonal sphenoid is bounded
by four equal isosceles triangles.
The rhombic sphenoid is bounded by
four equal scalene triangles.
The oblique sphenoid is bounded by
four scalene triangles, two larger and
two smaller.
Spherical. A term applied to those
mineral specimens which occur in a form
approximating to a sphere, as some va-
rieties of Aragouite or Malachite. It is
an extreme mammillary form.
Stalactites. The cylinders or cones
which hang from the roofs of some ca-
verns, especially limestone caverns, are
so-called. They are deposited by the
water which percolates through the roof.
As it evaporates, the dissolved carbonate
of lime remains behind and so forms
a hanging mass.
Some havs a granular, some a crystal-
line, fibrous, or radiating structure, while
some are quite hollow. Fine stalactites
of calcedony have occurred in many
Cornish mines, especially at North Pool
and Huel Alfred, many years ago ; and
quite recently at Pednandrea. At the
latter locality some of the specimens are
surrounded with minute crystals of ordi-
nary quartz, so that they have been mis-
taken for stalactitic quartz.
Stalactites of hydrous oxide of iron are
very common in the old workings of
many mines.
Stalactites of sulphate of iron have oc-
curred at Huel Prosper, in old workings.
96
STALACTITIO.
STEATITE.
Stalactites of psilomelane have oc-
curred at Kestormel Eoyal Iron Mines,
associated with lithomarge.
Stalactitic Minerals which occur in
forms resembling icicles are said to be
stalactitic.
Stalagmites are formed in the same
manner as stalactites, but they occur on
the floors of caverns. Large dome-shaped
masses are sometimes found in old work-
ings, and in limestone caverns the cone-
shaped stalagmites sometimes so ncrease
in size as to meet and join the stalactites
depending from the roof, so forming rude
pillars.
Stanniferous. Containing tin.
STANNITE.
[Stannine. Tin Pyrites. Bell Metal
Ore, &c.] Cubic? pyramidal? or amor-
phous; mostly occuring in compact or gra-
nular masses ; sometimes disseminated ;
brittle ; fracture uneven or granular ;
opaque ; lustre metallic ; steel-grey to
iron-black ; sometimes yellowish; streak
black; H. 4 ; G. 4 "3-4 '6.
B., etc. In matrass decrepitates and
gives off a yellow sublimate ; in open
tube gives off SOg, and often deposits a
white incrustation of Sn02 ; on C fuses
readily to a brittle magnetic bead, deposit-
ing a white incrustation ; with borax yields
the reactions for copper ; decomposed by
HNO3, forming a green solution, with
separation of S and Sn02.
Comp. Anhydrous sulphide of copper
and tin, with some iron. Many miner-
alogists regard it as an intimate mixture
only of oxide of tin and chalcopyrite.
Of the following analyses a. and b. are
of specimens from St. Agnes, by Klap-
roth ; c. is from St. Michael's Mount, by
Mallet ; d. from St. Michael's Mount, by
Johnston ; e. from Huel Rock, by Ku-
dernatsch : —
a. b. c. d. e.
Tin 84-0 26-5 26 -85 31 '618 25'55
Copper 36-0 30'0 2918 23'549 29'39
Iron 2'012-Q 673 4791 12'44
Zinc — — 7-26 10113 177
Sulphur 25-030-529-46 29 '929 29 "64
Gangue — — 016 — 1-02
Total 97-0 99-0 99'64 lOO'OOO 99'91
Loc. Botallack ; St. Michael's Mount ;
South Huel Crofty, Cam Brea, and East
Pool, recently; Barrier (?) Mine, Gwen-
nap; Scorrier Consols; Huel Rock and
Huel Primrose, St. Agnes ; Stenna
Gwynn; St. Stephens; Lanescot It has
been found also in Ireland and in Ger-
many.
STA UROLITE.
[Staurotide.] Rhombic; in six-sided
prisms (Fig. 116, &c.); orinmacles inter-
secting each other, as in Figs. 117, 118 ;
brittle ; fracture conchoidal or uneven ;
translucent to opaque ; lustre vitreous to
resinous ; dull reddish-brown or black ;
streak white or greyish ; H. 7-7 '5 ; G.
3-4-3-8.
B., etc. In matrass no change ; on C,
in fine powder, fuses at 4 to a black or
dark green slag; with borax slowly forms
a dark green glass ; with micro, a glass
almost colourless ; insoluble in HC1 ;
partly decomposed by H2SO4.
Comp. Anhydrous silicate of alumina
and iron. No analysis of a specimen
from Devon or Cornwall has been made,
but foreign specimens contain from 28
to 40 per cent, of silica, 44 to 53 per
cent, of alumina, 14 to 18 per cent, of
peroxide of iron, with, frequently, small
quantities of manganese, lime, or mag-
nesia.
Loc. It is said to have been found in
the clay-slate of Cornwall and Devon
(T. M. Hall, F.G.S., Min. Direct., pp.
52-63). The figures given may, perhaps,
lead to its re-discovery.
Obs. It has been found in Scotland,
Ireland, and many foreign localities,
usually in mica-slate, talc-slate, or clay-
slate, with garnet, kyanite, and tourma-
line.
STEATITE.
[Saponite, Dana. Soapstone; &c.]
Amorphous ; massive ; sometimes nodu-
lar; compact or foliated; sectile; fracture
splintery, slaty, uneven, or flat conchoi-
dal ; translucent to opaque ; lustre waxy,
glimmering, or dull; white, or various
tints of grey, yellow red, brown, green,
blue, &c.j H. l-2'5; G. 2 '2-2 '8 ; unctuous.
Far. The softer varieties are specially
called Saponite.
B. , etc. In matrass gives much water,
and sometimes turns darker; on C fuses
at about 4 to a vesicular glass or white
enamel ; some varieties infusible ; with
Co the infusible varieties often turn
reddish ; insoluble in HC1 or HNO3 ; de-
composed by hot H2SO4, with separation
of silica.
Comp. Hydrated silicate of magnesia
and alumina. Of the following analyses
a. and b. are by Klaproth, from the
Lizard ; c. and d. by Svanberg ; e. ,
by Houghton, from Gue Grease, a., c.,
and e. are given on the authority of
Descloizeaux : —
STEPHANITE.
STILBITE.
97
Silica
Magnesia
Alumina
Peroxide of iroi
Lime
a. b. c. d. e.
45-00 48-00 46-8 4219 42 "28
24-75 20-50 33'3 30'57 2970
9-25 14-00 8-0 7-67 7'21
l 1-00 1-00 0-4 — —
— — 07 — —
the solution yields a curdy precipitate
on addition of common salt or HC1.
Cornp. The author is not aware of any
analysis of a British specimen, but a
specimen from Schemnitz yielded to H.
Potash
"Water
075 — — — —
18-00 15-50 ll'O 18-46 18 '92
Ro>e 68*52 per cent, of silver, 0'64 per
cent of copper 14 '68 percent of anti-
Total . . .
98-75 99-00 100'2 98'80 98'11
mony, and 16 '42 per cent, of sulphur.
With silica 50*4 per cent., magnesia 34 "1
per cent., and water 15 '5 per cent, the
formula may be written MgSiH2 or
MgSiW3 + H2O or SiOMgo" + OH2. In
this case the alumina must be regarded
as replacing part of the silica. Dr.
Frankland gives the formula of steatite
as Si4O5Mgo"3, which is, perhaps, a va-
riety of talc, since it is anhydrous and
contains no alumina. Probably many
different minerals have been described
as steatite.
Loc. Kynance Cove, Mullion, Pedn-
boar, Cadgwith, Coverack, and other
parts of the Lizard district, in veins, in
serpentine ; near Trelowarren, in green-
ish-blue veins in olive-green serpentine ;
Penmare Point ; " In a tin lode in Carn-
yorth Moor, and in small veins in slate
to the south of Pendeen Cove;" "Bo-
tallack, in a tin and copper lode, with
oxide of iron ;" St. Ives ; Cook's Kit-
chen (lithomarge ?) St. Cleer, and near
the Cheesewring ; Pollaphant ; Clickor
Tor, in joints of impure serpentine, &c.
It occurs also in Cumberland, Wales,
Scotland, Ireland, and many foreign
localities.
Obs. It is best distinguished from
Lithomarge by the reactions for magne-
sia obtained by means of the blowpipe,
or in humid analysis. It may be distin-
guished from Agalmatolite in the same
manner, and by its inferior hardness.
Stellate. Occurring in the form of a
star, as is often seen in specimens of Py-
rolusite and other minerals.
STEPHANITE.
[Brittle Sulphuret of Silver. Black
Sulphuret of Silver.] Rhombic; in tabu-
lar or short columnar crystals ; or globu-
lar, massive, disseminated, or investing ;
sometimes drusy ; brittle, or sectile ;
fracture imperfect conchoidal to uneven ;
lustre metallic ; iron-black ; streak the
same; H. 2'5; G. 6 '2-6 '3.
B., etc. In matrass a white or yellow-
ish sublimate ; on C alone melts to a
dark grey bead, and deposits a white in-
crustation ; sometimes gives off an ar-
senical odour ; with soda or borax RF
yields a malleable bead of silver ; de-
composed by -warm HNO3, leaving oxide
of antimony and sulphur undissolved;
With 69'7 per cent, of silver, 131 per
cent, of antimony, and 17 '2 of sulphur
the composition will be Ag6SbSi0 or
Loc. Huel Ludcott, recently, with
fibrous native silver and beautiful half-
inch cube-octahedrons of argentite, in
brilliant crystals of 1£ lines long. (Davies'
Geol. Mag.)
STIBIGONITE.
[Stibiconise. Stiblite. Antimon-ochre
in part.] Amorphous, brittle ; fracture
uneven or earthy ; opaque ; dull or glim-
mering ; colour yellowish ; streak yel-
lowish-white, glimmering; H. 5'5 (?)
Greg and Lettsom, and Bristow); G.
5-28.
B., etc. In matrass yields water ; on
C is readily volatilized, depositing a
white coating on the support; with soda
is easily reduced to a white brittle me-
tallic bead ; soluble in warm HC1.
Comp. Hydrated antimonic oxide.
With antimony 71 '2 per cent., oxygen
23 '2 per cent,, and water 5 '6 per cent.,
which is not far from the composition of
some foreign specimens, the formula may
be written Sb2H2 or Sb2O5 + H2O.
LOG. "The antimony ochre accom-
panying Bleinierite and Jamesonite, at
Trevinnock, near Endellion. appears to
be this variety." (Greg and Lettsom,
p. 372.)
Stibine.
Stibium. V See Antimonite.
Stibnite.
t'4.)
bibine. \
tibium. \-
bibnite. J
STILBITE.
[Desmin. Foliated Zeolite. Sphsero-
stilbite.] Rhombic ; in modified prisms;
(Figs. 108, 109), the faces often curved,
striated, or rough ; cleavages highly per-
fect, parallel to a ; imperfect, parallel to
b ; often in groups of imperfect crys-
tals, laterally aggregated; also massive;
compact, columnar, or radiating ; brit-
tle ; fracture uneven ; semi-transparent
to translucent ; lustre vitreous, pearly
on cleavage planes ; white, grey, yellow,
brown, red, &c.; streak white; H. 3 '5-4;
G. 2-2-2.
B. , etc. In matrass gives off water ;
on C fuses with intumescence to a
98 STILPNOSIDEKITE.
SULPHIDE.
blistered glass or enamel ; -with Co. turns
blue ; slowly but completely decomposed
by HC1, leaving gelatinous silica.
Comp. Hydrated silicate of alumina
and lime. The Cornish specimens have
not been analysed, but foreign speci-
mens yield about 56 per cent, of silica,
15 '9 per cent, of alumina, 8 '6 per cent.
of lime, and 19 '5 per cent, of water.
"With these proportions the formula may
be written Al2Ca6Si-l- 7H2 or Al23Si03 +
CaSiO3 + 2H2SiO3+5H2O or Si6O6Al2Oiv
Cao" + 70H2.
Loc. The rocks between Botallack
and Huel Cock, " crystallized in flat
four-sided prisms, with wedge-like sum-
mits," with Prehnite and Mesotype (J.
Came, Trans. K. G. S. C., vol. II).
Found also in Scotland, Ireland, and
many foreign localities.
Obs. It usually occurs in granitic,
basaltic, or highly altered schistose
rocks, or in cavities of amygdaloidal
rocks ; sometimes, however, in veins or
"vugs."
Angles.
O a = 90° 00' r r' = 119° 16'
ab 90 00 Or 132 00
Ma 132 52
Stilpnosiderite. See Limonite.
Stream Tin. See Cassiterite.
Streak. The colour of the powder of
a mineral, a character of very consider-
able value in discrimination. Thus
Hematite may be distinguished from
Limonite by the redness of its streak ;
Wolfram may be readily distinguished
from Blende by its much darker streak.
This test admits of being tried in cases
where the sp. gr. cannot be easily deter-
mined, as in imbedded crystals, &c.
The colour of the streak is best deter-
mined by rubbing the specimen on a
slightly roughened plate of white porce-
lain, when, if not too hard, some of it
will be rubbed off. Very often a scratch
with a knife suffices, or rubbing with a
file, but the mark made in the mineral
— the scratch— must then be distinguished
from the colour of the abraded particles
— the streak.
Striated. Minerals which have small
channels on their crystalline surfaces are
said to be striated. The striations are
usually confined to certain planes, and
are often of value in discriminative
mineralogy. Thus in quartz the stria-
tions are horizontal, or across the
prisms ; while in topaz they are vertical,
or lengthwise. They are produced by
partial and interrupted changes in the
crystalline form.
Structure. This term relates to the
internal characters of minerals. It pro-
perly includes cleavage, and the various
kinds of fractures produced when miner-
als are broken. They are often very
characteristic. See page 34, Cleavage ;
and page 48, Fracture.
Sublimate. A vapour condensed to a
solid. "When fragments of Pyrites, or of
many other minerals, are heated in a ma-
trass, sulphur, &c., rises in vapour, and
is condensed on the cool part of the tube,
thus affording evidence of its presence.
The colours of sublimates, appearance
(crystalline or amorphous), and volatility
are characters of importance.
Sub-phosphate of Alumina. See Wa-
vellite.
Sulphates. Salts composed of sul-
phuric anhydride and a metallic oxide,
or sulphuric acid, in which the hydrogen
has been replaced by a metal. The sul-
phates occurring in the two counties are
the following : —
Anglesite, Johannite,
Barytcs, Kalinite,
Celestite, Langite,
Gypsum, Linarite,
Bruchantite, Melanterite,
Cyanosite, Woodwardite.
Goshirite,
Of these the first three are anhydrous,
the rest are hydrous. Connellite is a
sulphate-chloride.
Sulphate of Alumina and Potash. See
Kalinite.
Sulphate of Barytes. See Barytes.
Sulphate of Copper. See Cyanosite,
Brochantite, Langite, "Woodwardite.
Sulphate of Iron. See Melanterite.
Sulphate of Lead. See Anglesite and
Linarite.
Sulphate of Lime. See Gypsum.
Sulphate of Strontia. See Celestite.
Sulphate of Uranium. See Johannite.
Sulphate of Zinc. See Goslarite.
Sulphide. A non-oxidised compound
of sulphur and any metal.
The chief sulphides occurring in the
two counties are : —
Antimonite, Galena,
Argentite, Jamesonite,
Berthierite, Marcasite,
Bismuthinite, Millerite,
Blende, Molybdenite,
Bournonite, Pentlandite,
Chalcocite, Pyrites,
Chalcopyrite, Pyrrhotite,
Covellite, Stephanite.
Srubescite,
All the above are anhydrous. Besides
these there are the following sulphan-
timonides and sulpharsenides : —
SULPHIDE OF ANTIMONY.
TALC.
99
Cobaltite, Polybasite,
Fahlerz, Pyrzrgyrite,
Mispickel, Tennantite,
These are all anhydrous.
Sulphide of Antimony. See Antimo-
nite.
Sulphide of Bismuth. See Bismuthi-
nite.
Sulphide of Copper. See Chalcocite
and Covellite.
Sulphide of Copper and Iron. See
Chalcopyrite, Erubescite, and Fahlerz.
Sulphide of Iron. See Pyrites, Mar-
casite, and Pyrrhotite.
Sulphide of Iron and Antimony. See
Berthierite.
Sulphide of Iron and Nickel. See
Pentlandite.
Sulphide of Lead. See Galena.
Sulphide of Lead, Copper, and Anti-
mony. See Bournonite.
Sulphide of Lead and Antimony. See
Jamesonite.
Sulphide of Molybdenum. See Molyb-
denite.
Sulphide of Nickel. See MiUerite.
Sulphide of Silver. See Argentite.
Sulphide of Silver and Antimony. See
Stephanite.
Sulphide of Tin, Copper, and Iron. See
Stannite.
Sulphide of Zinc. See Blende.
SULPHUR.
Rhombic ; in modified pyramids, often
macled ; some of the planes striated ;
also drusy, globular, reniform, stalacti-
tic, investing, or massive ; brittle ; frac-
ture conchoidal or uneven ; transparent
to opaque ; lustre resinous to adaman-
tine ; yellow, or sometimes reddish,
brownish, greyish ; streak light yellow ;
H. 1-5-2-5; G. 2 -0-21.
J5., etc. In matrass sublimes in brown-
ish-yellow drops ; on C burns away with
a blue flame and a strong sulphureous
odour ; insoluble in HC1 ; scarcely acted
upon by HNO3.
Comp. The purest specimens almost
pure sulphur.
Loc. Formerly at Nangiles, in cavi-
ties of Pyrites, as a greyish pulverulent
deposit (J. Garby, Trans. R. G. S. C.,
vol. VII., p. 92); Poldice; more recently
by Mr. Davis, of the British Museum,
and by Mr. Tailing, of Lostwithiel, in
minute crystals, in the neighbourhood
of Liskeard or Lostwithiel.
Obs. Sulphur is often found as a
greenish -yellow efflorescence on the
ground in Carnou Valley after a long
continuance of dry weather. The author
saw it in many large patches in the sum-
mer of 1869 and also in 1870.
Sulphuret. See Sulphide, with which
it is synonymous.
Swamp Ore, Swampy Iron Ore. See
Limonite (Bog Iron Ore).
Swimming Quartz. See Quartz (Float-
stone).
Symbols. See Table of the Elements
in Part I.
T.
Tabular. Crystals which are nearly
flat are said to be tabular, whatever the
system of crystallization. The term is
also used to express a variety of struc
ture. Thus minerals which will cleave
into plates of a moderate degree of thin-
ness only, as Barytes, Wolfram, &c.5 are
said to be tabular.
TALC.
[Soapstone, in part.. Talc Steatite.
Lapis Ollaris.] Hexagonal ; very rarely
in six-sided tables, with perfect cleav-
age ; sometimes in thin pearly six-sided
plates ; more usually massive ; foliated,
slaty, granular, earthy, or compact ; sec-
tile, thin laminae flexible, but not elas-
tic ; semi-transparent to opaque ; lustre
pearly or waxy ; light-green, white, red-
dish, brownish; streak white, or much
paler than colour ; unctuous; H. 1-1 '5 ;
G. 2-6-2-8.
£., etc. In matrass usually gives off
a little water ; on C hardens, but remains
infusible ; often glows with an intense
light in a strong flame ; sometimes ex-
foliates or falls to pieces ; treated with
Co turns reddish ; with micro, forms a
turbid glass, leaving a siliceous skeleton ;
insoluble in HC1 or HNO3.
Comp. Silicate of magnesia, with a
little alumina and a small proportion of
water. No analysis of a specimen from
Cornwall or Devon is known, but a
Scottish specimen yielded to Lychnell,
64'53 per cent, of silica, 27 70 per cent,
of magnesia, 6 '85 per cent, of protoxide
of iron (a much larger proportion than
usual), and no water at all. With silica
69 "3 and alumina 30*7— regarding the
oxide of iron as accidental— the formula
would be 3Si2Mg or 2MgSiO3+SiO3 or
Si3O4Mgo"2.
Loc. It is said to have occurred at
St. Just; it is common at Kynance
Cove, and other places in the Lizard dis-
trict ; St. Stephens ; Beam Mine ; Stenna
Gwynn ; and St. Cleer.
Obs. Steatite may, possibly, have
been mistaken for Talc in the localities
100
TALLINGITE.
TIN PYEITES.
above mentioned. Steatite usually con-
tains a considerable quantity of water
and alumina, by the presence of which
it may be readily distinguished.
Tallingite. A variety of Atacamite
found at Botallack, and analysed by
Professor Church (Journ. Chem. Soc.
II., III., p. 77). See Atacamite.
Taste. A character of very limited
application in the discrimination of mi-
nerals, but very precise when applicable.
Thus, cyanoxite, goslarite, mclanterite,
halite, kalinife, &c., may be at once re-
cognised by their taste. The first three
have what is called a metallic taste ; the
others are saline.
TAVISTOCKITE.
[Soft Wavellite?] Rhombic ? in small
stellate aggregations of microscopic
acicular crystals ; brittle ; transparent
to translucent ; lustre pearly ; white ; H.
and G. unknown.
B. , etc. In matrass gives off water ;
on C incandesces and becomes opaque,
tinging the flame greenish ; with Co
turns blue ; with borax forms a colour-
less bead ; soluble with difficulty in HC1
or HN03.
Comp. Hydrated phosphate of alu-
mina and lime, as appears from the fol-
lowing analysis of a recently-discovered
specimen from the neighbourhood of
Tavistock by Professor Church (Journ.
Chem. Soc., II., III., p. 263, 1865):-
Phosphoric anhydride 30 '36
Alumina 22'40
Lime 36 '27
Water 1200
Total 101-03
Loc. Near Tavistock, in cavities on
Quartz, with Pyrite, Chalcopyrite, and
Churchite. The so-called Wavellite from
Stenna Gwynn was probably this miner-
al, as it was certainly not the true Wavel-
lite. It is described by Mr. Michell as
follows :— " Soft Wavellite, an assem-
blage of minute crystals, attached to
tufts of quartz, radiating sometimes like
a fine powder of down; colour white"
(Man. of Min. Truro, 1825, p. 157). It
was accompanied by Fluor, Cassiterite,
and Chalcopyrite in granite, while the
true Wavellite is on slate.
TENNANTITE.
Cubic ; in small dodecahedrons, octa-
hedrons, tetrahedrons, cubes, &c., usually
more or less modified (Figs. 3, 8 to 15,
37, 42, &c.); sometimes macled ; rarely
massive j brittle ; fracture uneven, im-
perfectly conchoidal, or laminated ;
opaque ; lustre metallic ; lead-grey to
iron-black ; streak dark reddish-brown ;
H. 4; G. 4-3-4-5.
B. , etc. In matrass decrepitates and
yields a reddish sublimate ; on C burns
with a blue flame, deposits a white in-
crustation, and melts to a dark brittle
magnetic bead or slag, giving off sul-
phureous and arsenical odours ; with
borax and micro, yields reactions for Cu
and Fe : after well roasting yields, with
soda, a bead of copper, but not readily ;
soluble in HNO>
Comp. Sulpharsenide of copper and
iron. Of the following analyses a. is by
Klaproth, of a specimen from Tresavean ;
b. by Kudernatsch, from the same loca-
lity ; c. by Phillips, from Cornwall ; d.
is the composition of an arsenical Fah-
lerz, by Hemming, from Gwennap, in-
troduced for comparison : —
a. b. c. d.
Copper 4770 48 '94 45 '32 48 '40
IroQ 975 3-57 9'26 14'20
Arsenic ... 12 '46 19 '10 11 '84 11 '50
Sulphur ... 30-25 27 '76 28 '74 21 "80
Silver — trace —
Silica . — 0-08 — 5 '00
Total... 10016 99'45 95 16 100 "90
With copper 42 6 per cent., iron 13 '2 per
cent., arsenic 17 '7 per cent, sulphur
26*4 per cent, the formula may be writ-
ten Cu3FeAsS7 or 2(Cu3Fe)S4 + As2S5.
With a substance of such variable com-
position many other formulae might be
made to serve.
Loc. Dolcoath ; North Roskear ;
Cook's Kitchen ; Tincroft ; Cam Brea ;
Huel Jewel ; Huel Unity ; Tresavean ;
Trevascus ; East Relistian, &c., but not
recently.
Obs. It is sometimes regarded as an
arsenical Fahlerz.
A ngles.
o o (Fig. 42) = 70° 32' a a = 90° OO7
oo' 109 28 dd 120 00
&c.
Mr. Greg's collection contained speci-
mens from Cornwall exhibiting the fol-
lowing forms, viz., d ; o d ; ad; m d ;
a o d ; o o' d ; a o d n.
Tetrahedrite. See Fahlerz.
Tetrahedron. A solid four:sided figure.
The regular tetrahedron is bounded by
four equal equilateral triangles (Fig. 33).
Tile Ore. See Cuprite.
Tin Hematite. See Cassiterite (Wood-
tin).
See Cassiterite.
Tin Pyrites. See Stannite.
TIN STONE.
TORBEKNITE. 101
Tin Stone. See Cassiterite.
Tin-white Cobalt. See Smaltite.
Titanite. See Ilmenite.
TITANITE.
[Spheue.] Oblique ; in modified pris-
matic or tabular crystals, often macled,
or imbedded ; sometimes granular, fo-
liated, or disseminated ; brittle ; fracture
conchoidal or uneven ; translucent to
opaque ; lustre resinous, vitreous, or
adamantine ; grey, yellow, brown, green,
black ; dichroic ; streak greyish ; H.
5-5-5; G. 3-4-3-6.
B., etc. In matrass unchanged; on
C swells up, or fuses slightly on thin
to a ds
lark glass ; with borax forms
a transparent yellow glass ; soluble, ex-
cept silica, in HC1; the solution if boiled
with tin-foil becomes violet ; decomposed
by H2SO4 with deposition of gypsum.
Comp. Silicate and titanate of lime.
With titanic anhydride = 41 '33, silica
30-45, lime 28-22, which is not far from
the composition of some foreign speci-
mens, the formula may be written
CaSiO3 + SiO2 + CaTiO3 + TiO2.
LOG. Virtuous Lady Mine, in small
yellowish crystals, imbedded in chlorite
with anatase. Found also in Scotland,
Wales, and Ireland, at many localities,
but always rare, and usually in gneiss or
syenite. It also occurs at many foreign
localities.
TOPAZ.
Khombic ; in modified prisms, usually
striated longitudinally, attached or
imbedded (Figs. 148, 149); perfect
cleavage parallel to O ; sometimes in
druses ; rarely massive, or disseminated,
in roundish grains, in veins or water-
worn pebbles ; brittle ; fracture uneven
or conchoidal ; transparent to translu-
cent ; lustre vitreous to pearly ; colour-
less, yellow, brownish, bluish, or green-
ish ; streak white; H. 8 ; G 3 '4-3 '6;
pyro-electric.
B . etc. In matrass no change ; on C
infusible, or fusible at 4 to a blistered
enamel; with borax melts slowly to a
clear transparent glass ; with Co turns
blue ; with micro, in a matrass yields
distinct fluorine reactions ; insoluble in
HC1 or HNO3 ; partly decomposed by
H2SO4, with evolution of HF.
Comp. Anhydrous silico-fluoride of
alumina. No British specimen has been
analysed, but foreign specimens yield
about 38 per cent of silica, 56 of alu
mina, and 16 of fluorine. All the for-
mulse given are exceedingly long, and
useless as aids to the memory. Professor
4. r. Gregor first detected
potash in the Cornish topazes (Ann
Phil., vol. VIII., p. 276).
Loc. St. Michael's Mount, in colour-
less or bluish crystals, much like Fig.
148, with lepidolite, tourmaline, cassi-
terite, fluor, apatite, &c., in the joints
of the granite ; Lamorna Cove, under
similar circumstances ; Constantine and
Mabe, in small bluish crystals in granite ;
Huel Kind, Trevaunance, and Seal Hole
Tin Mines, St. Agnes, in slate; St. Kea;
St. Austell Hill Mine, in a lode, in gra-
nite, with cassiterite, quartz, tourmaline,
felspar, &c. It is also said to have been
found on Lundy Island. It occurs at a
few localities in Scotland and Ireland,
but is never plentiful. Very fine speci-
mens occur at many foreign localities,
especially in Saxony and Brazil.
Obs. It may be readily distinguished
from quartz and other minerals which
somewhat resemble it by its perfect and
easily obtained basal cleavage, longitu-
dinal striation, and hardness. It mostly
occurs associated with other minerals
containing fluorine, in granitic or schis-
tose rocks.
A ngles.
M M' = 124' 19' O k = 116° 12'
MO 90 00 Oi 119 05
Ma 117 50 ki 155 13
Oa 90 00 kkf 130 27
Oe 147 41 IT 86 52
On 136 29 o o' 141 07
Oy 117 47 nn' 87 01
Oo 134 32
TORBERNITE.
[Uranite, in part. Chalcolite.] Py-
ramidal ; usually in thin tables, more or
less modified on the edges and angles
(Figs. 74, 75, 76, 84); perfect basal cleav-
age (O); sectile ; transparent to translu-
cent ; lustre vitreous to adamantine,
pearly on cleavage ; green of various
shades, sometimes yellowish-green; streak
light green; H. 2-2 '5; G. 3-3 '6.
B., etc. In matrass gives off water
and becomes dark and opaque : on 0
swells slightly and fuses to a dark mass,
which, on cooling, presents a crystalline
surface ; with soda yields with some
difficulty a small bead of copper ; with
borax and micro, yields Cu reactions;
soluble in HNO3, forming a green solu-
tion.
Comp. Hydrated phosphate of ura-
nium and copper. Of the following
analyses of Cornish specimens a. is by
Phillips ; b. by Berzelius ; c. from Gun-
nislake, by Werther; d. by Pisani;
102 TOEBERNITE.
TOUEMALINE.
e. by Prof Church (Chemical News, XII.,
183):—
a. b. c. d. e.
Phosphoric
anhydride.. 16'00 15'57 14'34 14'00 13'94
Oxide of ura-
nium ...... 60-00 61-39 59-03 59-67 61 "00
Oxide of cop-
per ........ 9-00 8-44 8'27 8'50 8'56
Water ...... 14'50 15'65 15 -39 15 '00 1410
Silica ........ — — 0-49 0"40 —
Earthy mat.. — — 0'41 — —
Arsenic anhy-
dride ...... — — — — 1-96
Lime ........ — — — — 0'62
Total.... 99-50 100-45 97 '93 97 '57 100 "24
With oxide of uranium = 61 '2 per cent.,
oxide of copper = 8 '4 per cent., phos-
phoric anhydride 15 '1 per cent., and
water 15 '3 per cent, the formula may be
written Cu, 2U2, PjSH, or CuO, 2U2O3,
P2O5 + 8H2Oor2U2O3, P2O5 + CuH2O2 +
7H20.
LOG. Huel Edward, St. Just, formerly,
with autunite ; Huel Trenwith ; Provi-
dence Mines ; Huel Buller, in dark green
crystals ; South Huel Basset, with autu-
nite ; South Huel Frances ; Tin croft ;
Tolcarne, with autunite ; Huel Gorland ;
Huel Unity ; Ting Tang ; Huel Jewell ;
St. Agnes ; Stenna G-wynn, in small pale
crystals, with fluellite ; St. Stephens ;
Huel James Copper and Iron Mine,
Withiel, in very fine dark green crystals,
in gozzan ; Gunnislake, very fine, form-
erly, in large thin aggregated plates,
with smoky grey quartz, at about 90
fathoms from the surface. Many years
ago very many specimens were raised
and sold from this locality.
Bedford United Mines, near Tavistock,
formerly, in small crystals.
It also occurs in Ireland, and in many
foreign localities.
Obs. It may be distinguished from
chalcophyllite by the form of the crys-
tals and the absence of arsenic ; from
autunite by its green colour and Cu.
reactions. J. Garby states that speci-
mens of "Chalcolite" were found at
" Huel Basset and Huel Buller which
were very phosphorescent when first dis-
covered, so that after the lights were
extinguished many of the crystals might
be discovered in situ." (Trans. R. G. S.
C., VII. , p. 86.)
Angles.
OM
MM
a a
Oa
Ma
Ot
90°
90
90
90
135
134
00'
00
00
00
00
50
O s =
Oo
Or
Ou
140°
136
111
109
Ov 107
07'
45
45
34
35
The Cornish forms observed are, ac-
cording to Greg and Lettsom, e, e O,
evO, evOt, rO, rsO, rsOa, rsOt,
rvOt, oO, uoO, xoO, MoO, SuO,
sOa, MrO, MrOa, MrsOt, MusOl,
MusOa. Most of these were in Mr.
Greg's collection.
Touch. A character of some import-
ance in the discrimination of some
minerals. Thus Graphite feels unctuous,
while Pyrolusite feels harsh.
Tough. Not easily broken. Ex. Horn-
blende. The term is used in contradis-
tinction to brittle.
TOURMALINE.
[Schorl.] Hexagonal ; in longitudinally
striated prisms, usually imbedded, or
ining nests or " vugs ;" often acicular
and interwoven ; sometimes in distinct
crystals, the termination at least like
those shewn in Figs. 212, 215, 216;
often massive ; columnar, fibrous, par-
allel, or divergent ; or compact ; very
brittle ; fracture sub-conchoidal or un-
even ; semitransparent to opaque ; lustre
vitreous, often splendant, sometimes
only glimmering ; sometimes white, red,
blue, pink, or mottled, but more usually
brown, green, or black ; streak white ;
H. 7-7-5 (if Zeuxite is a variety the H.
is as low as4); G. 2 '9-3 '3; pyro-electric ;
frictio-electric.
Var. 1. Schorl is the dark coloured
and nearly opaque variety, containing a
large proportion of iron, which is com-
mon-in many of the granites of Devon
and Cornwall.
2. Zeuxite is, perhaps, a variety. It
occurred in translucent, four-sided green-
ish-brown prisms.
3. Kubellite is a red and semitrans-
parent variety.
4. Indicolite is blue and semitrans-
parent.
5. Peridot is yellow and semitranspa-
rent.
6. Achroite is colourless and trans-
parent.
These last four are all foreign.
B., etc. In matrass no change; on C
fuses at about 3 to a dark usually mag-
netic slag ; with fluor and bisulphate of
potash melts and colours the flame green;
with borax and micro, the dark varieties
usually give reactions for iron ; insoluble
in HC1 or HNO3; the powder slowly de-
composed by H2SO4.
Comp. Anhydrous silico-borate of
alumina and various bases. Of the ac-
companying analyses a. and b. were fine
black specimens from Bovey Tracey,
analysed by Mitscherlisch, and Gmelin ;
TOUEMALINE.
UMBEE.
103
•c. is the analysis of
Unity, by Thomson,
Silica
Boric anhydride...
Alumina
Peroxide of iron ...
Protoxide of iron..
Oxide of manganese
Magnesia
Lime
Soda
Potash
Phosphoric anhyd.
Fluorine
"Water and loss ..
Zeuxite, from Huel
for comparison : —
b. c.
35-20 33-48
411 —
35-50 31 -85
a.
37-00
7-66
33-09
9'33
619 26-01
- 1-43 -
2-58 0-70 —
0-50 0-55 2-46
1-39 2-09 —
0-65 — —
012 — —
1-49 — —
— — 5-28
Total lOO'OO 97-44 99'08
With silica = 39 '3 per cent., alumina
45 '0 per cent., and protoxide of iron 15 '7
per cent, the formula might be written
Fe2AL3Si or FeSiO32Al2SiOg or AIS
(SiO3)3 + (A12O3 + B2O3) + FeO. It would,
however, tlms become necessary to re-
gard part of the alumina as being re-
placed by boric anhydride. A general
formula for all the tourmalines is some-
times given as (3R, R2 Ba)f Si. Dana
gives a very large number of analyses
of tourmalines, from many localities.
LOG. CORNWALL — a. Black or very
dark green Tourmaline (Schorl). — Fine
specimens have occurred on Roscommon
Cliffs (Figs. 215, 216), Botallack Mine,
the Crowns, Boscaswell Downs, Bos-
cawen Cliffs, Cape Cornwall, Pendeen
Cove, with fine crystals of felspar,
in schorl rock, and many other loca-
lities in St. Just ; the Land's
End, brownish and radiating; Wicca
Cove, near Zennor ; Kosemergy and
Morvah United ; near the Logan Kock ;
Ding Dong; St. Michael's Mount ; Huel
Darlington; Great Work, Breage, in
fine dark brownish-green radiating
masses ; Constantine ; Mabe ; Trevalgan,
St. Ives Consols, and other places in St.
Ives ; Providence Mines ; Herland and
Relistian, in Gwinear; Huel Druid,
Dolcoath, Cook's Kitchen, Cam Brea,
Ting Tang, West HuelJewell, and many
other localities in Gwennap ; Carclaze,
and other localities near St. Austell ;
Luxulyan, in porphyry, near the Via-
duct ; St. Cleer, in granite ; Kit Hill
United, &c.
DEVON — Very fine black crystals, like
Fig. 212, occurred many years ago in a
quarry of red granite at Chudleigh ; near
Bovey Tracey, associated with fine crys-
tals of white and translucent apatite.
Good specimens, not distinctly crystal-
lized, have occurred near Chagford;
Birch Tor Mine, North Bovey ; Bovey
Heathfield ; Haytor ; near Okehampton ;
Blatchford, near Corn wood ; Holme Lee ;
Buckfastleigh ; TJgborough Beacon ;
Bowdley, near Ashburton ; generally on
the flanks of the granitic mass of Dart-
moor ; and Lundy Island.
b. Green Tourmaline occurs on the
flanks of Cam Marth, and in white gra-
nite at Okehampton.
c. Achroite (?) occurs at Roscommon
Cliffs, St. Just, in "small transparent
colourless crystals, "associated with black
crystals, like Figs. 215, 216, and with a
massive variety, with finely laminated
aad radiated structure.
d. Zeuxite occurred in the year 1814
at Huel Unity, in small translucent
greenish-black crystals, much interlaced.
(See PhiUMag., August, 1855.)
The foreign localities of the various
forms of tourmaline are exceedingly
numerous.
Obs. Tourmaline may be easily dis-
tinguished from substances which some-
what resemble it by its specific gravity,
longitudinal striations, brittleness, pyro-
electricity, and by the form of the crys-
tals when distinctly crystallized.
Angles.
R R = 133° 08' a t = 142° 26'
R'e' 156 34 a a' 120 00
R o 152 40 a b 150 00
Rs 141 30 bb 120 00
Ra 113 26 so 134 02
as 128 30 ee' 154 59
Towanite. See Chalcopyrite.
Translucent. See Diaphaneity.
Transmitted Light. See Reflected
Light.
Transparent. See Diaphaneity.
Tremolite. See Amphibole.
Truncated. A term which is used in
the same sense as Modified, which see.
Tungstate of Iron. See Wolfram.
Tungstate of Lime. See Scheelite.
Tungsten. See Scheelite and Wol-
fram.
Tungstic Acid. }
Tungstic Anhydride. > See Wolframite
Tungstic Ochre. J
U.
Umber. See Limonite.
Uncleavable Fluor. See Fluor (Chlo-
rophane).
Uncleavable Manganese Ore. See
Psilomelane.
Uncleavable Uranium Ore. See Pitch-
blende.
104
UNCTUOUS.
YINIANITE.
Unctuous. Such minerals as feel slip-
pery when handled are said to be "unc-
tuous." Ex. Graphite, Lithoraarge,
Steatite.
Uneven. See Fracture.
Uranite. See Torbernite and Autu-
nite.
Uranium. "I
Uranium Ochre. V See Pitchblende.
Uranium Ore. J
Uran Mica. See Autunite and Tor-
bernite.
V.
VALENTIN1TE.
[Oxide of Antimony, in part.] Khom-
bie ; in prisms, with some faces curved
or rough ; longitudinal cleavages, very
perfect ; sectile ; fracture not observ-
able ; semitraosparent to translucent ;
lustre adamantine or pearly ; white, to
grey, yellow, brown, or red ; streak
white; H. 2'5-3'0 ; G. 5 '5-5 "6.
B., etc. In matrass sublimes com-
pletely ; on C melts at 1, and deposits a
crystalline white incrustation on the
support ; if mixed with soda and cyanide
of potassium is readily reduced to a grey
brittle bead, tinging the flame green ;
with borax forms a glass, which is yellow
while hot, nearly colourless on cooling,
like senarmontite ; soluble in Aqua Be-
gia, and re-precipitated on addition of
water, if the solution be concentrated.
Comp. Anhydrous oxide of antimony
like senarmontite. Sb2 or Sb2O3, which
.is, therefore, dimorphous.
Loc. It is said to have occurred in
white, fibrous, and radiated masses, with
other antimony ores, at Lee, near Cal-
lington. It occurs also at several locali-
ties in Bohemia, Germany, France, &c.
06s. It is to be distinguished from
senarmontite by its crystalline form.
Variegated Copper Ore. See Erubes-
cite.
Variegated Vitreous Copper is a mix-
ture of Chalcocite and Chalcopyrite,
found in some copper mines. It has the
colours of tempered steel.
Vesicular. See Cellular.
Vitreous. See Lustre.
Vitreous Copper Ore. See Chalcocite.
Vitreous Silver Ore. See Argentite.
VIVIANITE.
[Phosphate of Iron. Blue Iron Earth.]
Oblique ; in prisms more or less modi-
fied (Figs. 168, 169, &c.); with perfect
clino-diagonal cleavage (b) often acicular,
aggregated, or divergent ; also globular,
reniform, fibrous, or earthy ; sometimes
investing other ores of iron ; sectile, thin
plates flexible ; transparent to opaque ;
lustre pearly, vitreous, or sub-metallic ;
pale green to deep blue ; crystalline or
foliated specimens dicbroic, often red-
dish or yellowish in some directions, and
sometimes much like some micas ; earthy
varieties a very pui'e blue colour ; streak
bluish white, darkens on exposure, colour
of powder liver-brown when dry ; H.
1-5-2 ; G. 2-6-2 7.
Var. a. Crystallized Vivianite, often
green, sometimes emerald-green and
transparent.
b. Blue Iron Earth. Soft, earthy, and
without lustre ; colour a very beautiful
pale blue. It is sometimes nearly white
when first obtained.
B., etc. In matrass gives off much
water ; on C melts at 1 to a grey shining
magnetic bead, colouring the flame bluish-
green ; with borax and micro, gives Fe
reactions ; soluble in HC1 and HNOs.
Comp. The following analysis of a
specimen from St. Agnes is by Stro-
meyer : — •
Phosphoric anhydride 31 "18
Oxide of iron 41 '23
Water 27'48
Total
99-89
Loc. Botallack and Huel Edward,
St. Just, formerly, and again at Huel
Edward, recently, in fine foliated masses
of greenish, reddish, yellowish, and
brownish colours, also in acicular crys-
tals, and as Blue Iron Earth ; Park-
noweth, formerly, compact and earthy ;
Huel Gorland ; Huel Jane and Huel
Falmouth, in fine flat crystals on pyrites
and pentlandite ; Huel Kind, formerly,
in the finest crystals ever found, some
two inches long and three-quarters of an
inch across, on pyrrhotite with chaly-
bite ; Huel Betsy and Huel Friendship,
near Tavistock. Found also in alluvium
near Bristol, and in mud in the Isle
of Dogs, London, as well as in several
other British and many foreign locali-
ties.
Obs. The Cornish crystals are not
often distinctly terminated.
Angles.
O M = 117° 40' v b = 120° 25'
Oa 125 47 y y' 154 14
Ov 149 35 ya 167 07
MM' 111 12 br 109 34
Ma 145 36 bz 105 19
Mb 124 24 na 144 20
WAD.
WAVELLITE. 105
w.
"Wad. A Cumberland name for gra-
phite.
WAD.
[Earthy Manganese. Bog Manganese.]
Amorphous ; often reniform, botryoidal,
arborescent, pulverulent, or investing;
occasionally so full of cavities as to ap-
pear frothy ; sometimes with a curved
lamellar structure ; sectile or brittle ;
fracture earthy ; opaque ; lustre sub-
metallic, glimmering, or dull; dark
brown or nearly black ; streak dark
brown ; scratch shining ; soils the fingers ;
H. 0 to 3-0; G. 2-37.
B. , etc. In matrass yields much water ;
on C infusible ; with borax or micro,
gives reactions for Mn ; soluble in warm
HC1, giving off Chlorine.
Comp. Impure hydrated manganic
oxide, with often a proportion of oxide
of cobalt, in which case it may be re-
garded as passing into asbolane. Some-
times a quantity of black oxide of copper
is present. The following analysis of a
specimen from Upton Pyne is by
Turner :—
Manganic sesquioxide 79 12
Oxygen 8'82
Water 10'66
Boric oxide.... 1'40
Total 10000
LOG. Huel Bucketts ; Pednandrea ;
South Tolgus ; Gerrans ; Lifton, near
Launceston, in botryoidal masses ; Upton
Pyne, in dark brown masses of very low
specific gravity. It occurs also in Der-
byshire and Scotland; and in Germany,
France, and other foreign localities.
Warringtonite. See Brochantite.
WA VELLITE.
[Hydra rgillite.] Rhombic; usually in
hemi-spherical or globular masses, with
radiated structure ; brittle ; fracture un-
even or sub-conchoidal ; translucent ;
lustre pearly, ailky, or vitreous ; yellow-
ish, greyish, greenish, bluish ; sometimes
a brown or black tarnish ; streak white ;
H. 3*5-4 ; G. 2 "3-2 '4.
B., etc. In matrass yields water and
turns white ; on C fuses with intumes-
cence to a white opaque mass, tinging
the flame bluish-green ; with Co turns
blue ; soluble in HC1, HNO3 and KHO ;
with micro, yields traces of fluorine.
Comp. Hydrated phosphate of alu-
mina, as appears from the following
analyses of specimens from Barnstaple.
a, and b. by Fuchs, c. by Berzelius :— •
Phosphoric anhyd... 3512 34 *84 33 '40
Alumina 37'20 3716 35 "35
Fluorine — . 2'06
Peroxides of iron &
manganese — 1-25
Lime _ __ Q'50
Water 28'00 28 "00 26 "80
Total 100-32 lOO'OO 99'36
With phosphoric anhydride — 35 1 per
cent., alumina = 33 '2 per cent., and
water = 26 '7 per cent, the formula may
be written 3A122P2 + 12H2 or 3AL,O,2P,
05 + 12H20 or P40(A1206)3120H2.
The following analyses, d. from Barn-
staple, by Klaproth ; e., ditto, by Davy;
f., Cornwall, by Gregor, are given in
Jameson's Mineralogy, I., p. 334, 1816:—
(Phosphate) alumina 71 '50 70 "0 58 '70
Oxide of iron 0'50 — 019
Lime — 1-4 0-37
Silica — — 612
Water 28'00 26'2 3075
— 2-4 3-87
Total lOO'OO 100.0 lOO'OO
Loc. It is said to have been found at
Beam Mine ; at StennaGwynn, on decom-
posing granite, in greyish-green radiated
masses, about as large as peas ; and at
Kit Hill, on elvan. The best known lo-
cality is Filleigh, near South Molton,
near Barnstaple, on clay-slate.
Obs. " It was first discovered about the
year 1785, by Mr. I. Hill, of Tavistock,
and, being mistaken for a pure hydrate
of alumina, it was called Hydrargillite,
until Dr. Wavell, of Barnstaple, about
thirty years afterwards, shewed that
phosphoric acid was present in large
quantities, and the substance, which
thus constituted a new species, was
named Wavellite. The usual form of
this mineral is that of a hemisphere,
varying in size from ene-twentieth of an
inch to one inch in diameter. When
broken, the internal structure is found
to be composed of acicular crystals,
finely radiated. Wavellite is also found
frequently filling small crevices in the
slate rock, and not having had sufficient
space to crystallize in its primary form,
it has accommodated itself to the breadth
of the fissure, spreading out and covering
the surfaces of the rock with a profusion
of radiated circles, which are sometimes
two inches in diameter, and vary in
thickness from one-eighth to a film not
more than l-200th of an inch " (Trans.
Dev. Assoc., vol. II., pt. II., p. 341
1868). Wavellite has also occurred in
106 WHEEL OEE.
WOLFRAM.
Northumberland, Scotland, Ireland, and
many foreign localities.
Wheel Ore. See Bournonite.
"White Antimony Ore. See Senarmon-
tite and Valentinite.
White Arsenic. See Arsenolite.
White Cobalt. See Cobaltite and
Smaltite.
White Lead Ore. ) « rpr.18site
White Lead Spar, f b lte>
White Mundic. See Leucopyrite, Mar-
casite, and Mispickel.
White Iron Pyrites, White Sulphuret
of Iron. See Marcasite.
White Vitriol. See Goslarite.
Wild Lead. An old term for Blende.
WITTIGHENITE.
Rhombic, in small, nearly square
prisms ; more usually in imperfect ag-
gregations of acicular crystals with one
perfect vertical cleavage ; or massive,
with coarse columnar cleavage ; also dis-
seminated ; brittle ; opaque ; lustre me-
tallic ; tin-white to steel-grey ; readily
tarnished by exposure to light or air
streak black ; H. 3'5 ; G. 4 '3-5.
S., etc. In matrass yields a light sub-
limate ; in open tube gives a white sub-
limate and a strong sulphureous odour ;
on C fuses at 1, giving off brilliant sparks
and coating the support dark brownish-
yellow ; with soda yields a globule of
copper ; soluble in HC1 or HNO3 ; the
solution yields a white precipitate when
largely diluted with water.
Comp. Anhydrous sulphide of bis-
muth and copper. A specimen from
Baden yielded to Klaproth 47 '24 per
cent, of bismuth, 34 '66 per cent, of cop-
per, and 12 '58 per cent, of sulphur.
Loc. The " Cupreous Bismuth,"
formerly reported from Botallack, Le-
vant, and Huel Buller may, possibly,
have been this species. That from Huel
Buller occurred " in perfect hexagonal
prisms, tin-white and lustrous when first
raised, but soon becomes dull and tar-
nished." (Garby, Trans. R. G. S. C.)
WOLFRAM.
[Tungstate of Iron.] Rhombic ; some-
times in crystals, like Figs. 118, 119,
with perfect and easily obtained cleav-
age parallel to M ; less perfect par-
allel to b u ; crystals are usually im-
bedded, and often striated, curved, or
macled ; sometimes in acicular crystals;
often massive ; brittle, fracture uneven ;
opaque ; lustre metallic or sub-metallic,
brilliant on freshly exposed surfaces ;
dark greyish or brownish-black, not un-
frequently with an iridescent tarnish ;
streak dark reddish -brown; H. 5-5 "5 ;
G. 7-7 '6 ; some specimens feebly magne-
tic.
J5., etc. In matrass decrepitates
strongly and breaks up into thin flakes,
but is otherwise unchanged ; on C fuses
at 4 to a black magnetic mass, sometimes
crystalline on the surface ; fused with
soda forms a green mass ; with borax
and micro, gives Fe and Mn reactions ;
slowly decomposed by warm HC1, more
readily with Aqua Regia, with deposition
of yellow tungstic anhydride.
Csmp. Anhydrous tungstate of iron,
with some manganese, as appears from
the following analysis of a specimen from
Godolphin Bal by Kerndt, the specific
gravity of which was 7 '21 : —
Tungstic anhydride 75 '92
Oxide of iron 19'35
Oxide of manganese 4'73
Total lOO'OO
With tungstic anhydride = 7710 per
cent., oxide of iron = 18'27 per cent.,
and oxide of manganese = 4 '63 per cent.
the formula might be written 4Fe,
Mn5W or (4-5 Fe 1-5 Mn)WO4.
Loc. St. Michael's Mount, with cas-
siterite, fluor, topaz, &c. ; Godolphin
Bal, Breage ; Huel Prospidnick, Sithney ;
Herland; Dolcoath; Cook's Kitchen;
Tincrof t ; Cam Brea ; East Pool, in aci-
cular crystals, and in large macles, with
striated or curved surfaces, imbedded in
quartz or chlorophane ; Pednandrea, im-
bedded in chlorite, both massive and
crystalline ; Huel Fanny, in prisms
(Figs. 245, 246); Huel Harmony ; Pol-
dice, massive and acicular, in quartz and
chlorite; Cligga; Stenna Gwynn, crys-
tallized ; Beam Mine ; Gobnbarrow ;
Gunnislake ; Drake Walls, fibro-lamel-
lar and massive ; Kit Hill ; &c. Wol-
fram has also been found at Huel Friend-
ship and several other mines near Tavis-
tock.
06s. The Cornish specimens, although
often very fine and pure, are seldom dis-
tinctly crystallized, they are frequently
imbedded in quartz, in large cleav-
able masses or imperfect tabular crystals.
Wolfram may be distinguished from Cas-
siterite by its perfect cleavage, inferior
hardness, and dark streak ; from Blende
and Schorl by the colour of its streak,
and by its sp. gr.
Angles.
M M = 101° 05' b a = 90° 00*
Mt 110 46 bt 117 20
Mb 140 32 uu 99 12
The plane M is striated vertically.
WOLEKAMITE.
ZIPPJEITE.
107
WOLFRAMITE.
[Wolframine. Wolfram Ochre.] Cubic?
in earthy or pulverulent masses, invest-
ing wolfram ; opaque ; dull ; yellow,
greenish, or brownish ; H, 0-1.
B., etc. In matrass gives off water and
turns black ; on C infusible ; with borax
forms a colourless bead, unlike the other
minerals with which it may be confound-
ed (Yellow Ochre, Zippseite, &c.); inso-
luble in HC1; soluble in caustic alkalies.
Comp. Hydrated (?) oxide of Tungs-
ten, or, more probably, tungstic anhy-
dride which has absorbed some moisture
from the air.
LOG. East Pool, Poldice, Drakewalls,
and Huel Friendship, investing wol-
fram. Found also in Cumberland, France,
and the United States.
Wood Arseniate of Copper. See Oli-
venite.
Wood Iron Ore. See Limonite.
Wood Tin. See Cassiterite.
Woodwardite, An impure Langite, or
mixture of Langite and Allophane. It
occurs in minute concretions of a tur-
quoise-blue or greenish-blue colour, and
is translucent or almost transparent ;
sp. gr. 2*38. It is soluble, almost com-
pletely, in dilute HC1 or HNO3. Of the
following analyses the first, a., is by
Professor Church; b., c. are by War-
rington ; d. is a very similar mineral,
analysed by Pisani. In a., b., c. there
were traces of silica, lime, magnesia, and
phosphoric anhydride :— -
a. b. c. d.
Sulphuric anhy. 13'95 13 '04 12'54 11 '7
Oxide of copper 48 "34 48'67 4680 46'8
Alumina 17 '97 18 '64 17 '93 13 '4
Silica — — — 1-2
Water 18 '48 19 '65 22 "73 26 '9
Total 98-74 100 '00 100 '00 100 '0
Another mineral, much resembling
Woodwardite, yielded to Pisani : —
Sulphuric anhydride 4 '7
Oxide ot copper 17 '4
Alumina 33'8
Silica 6'7
Water 38'7
Total 101-3
M. F. Pisani therefore regards both
Woodwardite and this new mineral as
mixtures, in very different proportions,
of Langite and Allophane.
A specimen of a similar Cornish
mineral, examined recently by Professor
Maskelyne and Dr. Flight, had the com-
position given below. " It occurs in very
thin crusts, of various shades of yellow
and green, the surface exhibiting a wavy
appearance. Though the outer surface
is occasionally somewhat compact, the
mass is loose, and some of the layers pul-
verulent, a. shews the composition of
the inner layer, and b. that of the outer
crust": —
Ox. of copper.
Alumina
Lime ....
Magnesia
Soda ....
Sulph. anhyc
Silica
Oarb. anhyd.
Water: Lost a
ord. temp. .
100° . . .
1200-260" .
over 260<> .
a.
24-561
23-063
0-749
6-775
b.
10-255
27-250
1-403
6-183
0-640
2-433
7-538
0-528
15-390
10-413 )
7-333 |
5-392 6-167
38-528
23-864
Total .... 100-451 100-199
For further information see Church,
Chem. News, XIII., 85, 113, 1866, and
Journ. Chem. Soc., II., iv., 130; Pisani,
Phil. Mag., April, 1868, p. 320 ; Maske-
lyne and Flight, Journ. Chem. Soc.,
Jan., 1871, p. 1. See also Langite.
Y.
Yellow Copper Ore. See Chalcopyrite.
Yellow Ochre. See Limonite.
Yellow Oxide of Tungsten. See Wol-
framite.
Yellow Oxide of Uranium. See Zip-
Zeuxite. See Tourmaline.
£ gfij
Zinc Spar. See Calamine.
Zinc Vitriol. See Goslarite.
ZIPP&ITE.
[Uranochre, &c.] Amorphous : earthy
or pulverulent ; opaque ; dull ; lemon,
or sulphur-yellow, or sometimes brown-
sh-red; H. 0-1.
£., etc. In matrass yields water and
darkens in colour ; on C turns green but
does not fuse ; with borax and micro,
yields uranium reactions ; soluble in
ENO3, forming a yellow solution.
Comp. Oxide of uranium, probably
lydrated.
Loc. Huel Edward, St. Just; St.
108
ZIPP^ITE.
ZIPP^ITE.
Michael's Mount, coating mica on quart-
zose rock. "A specimen given to Mr.
Greg by Mr. Nuttall appears to be slightly
crystallized in plates, as if the result of
the decomposition of uranite ' " (Greg
and Lettsom, p. 382). Formerly in small
green earthy globules, on pitchblende,
at Huel Buller ; Carharrack ; more re-
cently at Pednandrea and Clyjah Mine ;
and at Goonbarrow (?); "Wlthiel Iron
Mine, Kestormel. Formerly in consider-
able abundance at a tin mine in Calling-
ton. Zippseite has also been found in
several foreign localities.
THE END.
TRURO :
PRINTED BY HEARD AND SONS,
BOSCAWEN-STREET.
ADDENDA.
ANTHKACITE.— The Author has found
thin layers in the joints of the rocks at
Pednandrea Mine, andatRoscrow United
Mines, Ponsanooth.
AXINITE.— Additional localities to
those on p. 12, Pt. II :— Old Treburgett,
St. Teath ; and Ivy Tor, Copper Hill
Mine, Huel Forest, Fursdon Manor
Mine, Meldon Quarry— all in Devon.
See Trans. Dev. Assoc., vol. II., Pt. II. ,
p. 344, 1868.
EL.EOLITB. — (Nepheline) Hexagonal ;
Brittle ; fracture conchoidal or uneven ;
transparent to semi-translucent; lustre
vitreous to resinous; colourless, grey,
red, brown, or bluish green ; streak
white, H. 5-5—6-0, G. 2 '58— 2 '64.
.B., etc. Infusible or fusible with diffi-
culty ; with Co. turns blue ; translucent
splinters become opaque if treated with
HNO3, Powder decomposed by HC1.
Comp. Anhydrous Silicate of Soda,
Potash, and Lime.
Loc. The Wolf Rock, nine miles S.E.
of the Land's End— with glassy Felspar
and green Hornblende in yellowish grey
masses of imperfect Crystals. "The
greater part of the mass of the rock is
seen to consist of 'Nephelinp,' the
1 "
Crystals varying in size' from the — -
1 " 150
to — across." S. Allport, F.G.S., in
310
Geol. Mag., June, 1871.
EPIDOTE. — A specimen from Old Tre-
burgett Mine, St. Teath, associated with
Axinite, is in the Museum of the Royal
Institution of Cornwall.
PITTICITE. — The following is an an-
alysis of a specimen from Redruth (Dol-
coath?) by Professor A. H. Church,
M.A.:-
" Carefully selected homogeneous por-
tions of a fine specimen of this mineral
from Cornwall were submitted to analy-
sis, after having remained a year or more
in my cabinet. They evidently still
contained a considerable amount of
hygroscopic water.
Water lost at 100° C 876
„ lost at 175° 7-53
„ retained at 175° 8'63
Ferric oxide..., 32'54
Arsenic pentoxide 33'99
Phosphorus pentoxide 1"27
Sulphur trioxide 7'28
100-00
Regarding the water lost at 100° as
non-essential or accidental, we may re-
calculate the above numbers as follows :—
Water 17'71
Ferric oxide 35'67
Arsenic pentoxide 37 '25
Phosphorus pentoxide 1 '39
Sulphur trioxide 7'98
lOO'OO
I fear that these numbers throw no
fresh light upon the constitution of this
very variable mineral, and that no satis-
factory formula can be deduced from
them. One peculiarity of the Cornish
specimens consists in the high proportion
of arsenic pentoxide which they contain,
a proportion which is greater than that
in this mineral as derived from any other
recorded locality. But, on the other
hand, the Cornish Pitticite shows a
smaller quantity of ferric oxide than
other analysed specimens. It does not
appear that phosphorus pentoxide has
been previously detected in this mineral.
I ought to add that the Cornish mineral
was straw to ochre-yellow in colour,
subreniform and massive in form, and in
great part opaque. The softest, palest,
and most homogeneous portions were
selected in preparing the sample for
analysis. It is not improbable that the
darker and less opaque portions would
have shown a higher percentage of iron.
ORTHOCLASE.— The following analysis,
by Professor Church (who has favoured
the author by communicating it), is of
ADDENDA.
an Orthoclase from a quarry near Roche,
where it occurs as a rock, in large sub-
opaque white masses, with thin veins of
wuite Quartz and white Mica. Its
specific gravity is 2 '56.
Silica 6370
Alumina 1976
Ferric oxide '71
Lime trace.
Potash 13-61
Soda .. 2-26
100-04
SILVER. — The following is an analysis
of a specimen from Huel Ludcott, by
Professor Church. Sp. gr. 10 '26.
Silver 97-86
Chloride of Silver '71
Gold and Antimony
Iron *15
Metals precipitable by H2S '10
Loss "97
100-00
PSEUDOMORPHS.— A fine specimen of
Calcedony in cubes — probably Pseudo-
morphous after Fluor — is in the Museum
of the Royal Institution of Cornwall.
It is believed to be from Beeralston.
HEMATITE occurs in irregular nodules
in brownish red clay near Totnes,
Devon.
Plata 1.
PLATE I.
CUBICAL SYSTEM.
Fig.
1. OCTAHEDRON. Cuprite, Fluor.
2. CUBE. Pyrites, Cuprite, Fluor.
3. KHOMBIC-DODECAHEDRON. Garnet, Cuprite.
4. TRIAKIS-OCTAHEDRON. Pyrites, Galena.
5. DELTAHEDRON. Garnet, Argentite, Analcite.
6. HEXAKIS-OCTAHEDRON. Fluor.
7. TETRAKIS-HEXAHEDRON (FOUR-FACED CUBE.) Fluor, Cuprite.
8. Kerate, Argentite, Cobaltite, Fluor, Galena.
9. Kerate, Argentite, Fluor, Galena.
10. Fluor, Blende, Galena, Silver.
11. Galena, Cuprite, Silver.
12. Galena, Cuprite.
13. Galena, Cuprite.
14. Galena, Cuprite.
15. Argentite, Cuprite.
16. Fluor, Cuprite, Pyrites.
17. Fluor.
18. Fluor, Smaltite.
19. Argentite, Analcite.
20. Argentite.
21. Fluor.
22. Fluor.
23. Fluor.
24. Fluor', Cuprite.
25. Garnet.
26. Garnet.
27. Fluor.
28. Fluor.
PLATE II.
CUBICAL SYSTEM (Cont.)
Fig.
29. Galena, Fluor.
30. Fluor.
31. Fluor, Garnet.
32. Pyrites, Fluor.
33. TETRAHEDRON. Fahlerz.
34. DELTOID-DODECAHEDRON. Fahlerz.
35. TRIGONAL-DODECAHEDRON. Blende, Fahlerz.
36. Diamond.
37. Blende, Tennantite.
38. Fahlerz.
39. Blende, Fahlerz.
40. Fahlerz.
41. Fahlerz.
42. Blende, Fahlerz, Tennantite.
43. PENTAGONAL-DODECAHEDRON. Pyrites, Cobaltite.
44. Pyrites, Cobaltite.
45. Pyrites, Cobaltite (very rarely.)
46. Pyrites, Cobaltite.
47. Pyrites.
48. Pyrites, Cobaltite.
49. Pharmacosiderite.
50. Pyrites, Pharmacosiderite.
51. Pharmacosiderite.
52. Pyrites, Blende.
53. Fluor.
late 11.
Plate #/.
PLATE III.
CUBICAL SYSTEM ( Cont.)
Fig.
^' | Illustrations of Macles. (See page 65)
55. Fluor. (Macled Octahedrons.)
56. Macled Octahedrons, Magnetite.
57. Macled Cube-Octahedrons.
58. Pyrites, Erubescite (Made.)
59. Copper.
60. Copper.
PYRAMIDAL SYSTEM.
Fig.
61. Cassiterite.
62. Cassiterite.
63. Cassiterite.
64. Cassiterite.
65. Cassiterite.
66. Cassiterite.
67. Cassiterite.
68. Cassiterite (Macled.)
69. Cassiterite (Macled.)
70. Cassiterite (Macled.)
71. Cassiterite (Macled.)
72. Anatase.
73. Anatase.
74. Torbernite.
75. Torbernite.
76. Torbernite.
77. Cassiterite (Macled.)
78. Cromfordite.
PLATE IV.
PYRAMIDAL SYSTEM (Cont.)
Fig.
79. Chalcopyrite.
80. Chalcopyrite.
81. Chalcopyrite.
82. Chalcopyrite.
83. Chalcopyrite.
84. Torbernite, Chalcopyrite (Macled.)
85. Chalcopyrite (Macled.)
86. Scheelite.
87. Scheelite.
88. Scheelite.
KHOMBIC SYSTEM
Fig.
89. Fluellite.
90. Mispickel.
91. Mispickel.
92. Mispickel.
93. Mispickel.
94. Andalusite.
95. Andalusite.
96. Prehnite.
97. Antimonite.
98. Bismuthinite.
99. Bismuthinite,
Pla^V.
102
120
PLATE V.
RHOMBIC SYSTEM (Cont. )
Fig.
100. Chalcocite.
101. Chalcocite.
102. Chalcocite.
103. Chalcocite (Macled.)
104. Chalcocite (Macled.)
105. Chalcocite.
106. Chalcocite (Macled.)
107. Chalcocite (Macled.)
108. Stilbite.
109. Stilbite.
110. Manganite.
111. Finite.
112. Natrolite.
113. Natrolite.
114. Wavellite.
115. Leucopyrite, Staurolite.
116. Staurolite (Macled.)
117. Staurolite (Macled.)
118. Wolfram.
119. Wolfram.
120. Bournonite.
121. Bournonite (Macled.)
122. Bournonite, Antimonite.
123. Bournonite.
PLATE VI.
RHOMBIC SYSTEM (C<mt.)
Fig.
124. Goethite.
125. Goethite.
126. Goethite.
127. Anglesite.
128. Anglesite.
129. Anglesite.
130. Anglesite, Barytes, Celestite.
131. Anglesite, Barytes, Celestite.
132. Anglesite, Barytes, Celestite.
133. Anglesite, Barytes.
134. Anglesite, Barytes.
135. Anglesite, Barytes.
136. Olivenite, Barytes, Pyrolusite.
•
137. Olivenite, Barytes, Pyrolusite.
138. Olivenite.
139. Libethenite.
140. Cenissite.
141. Cerussite.
142. Cerussite (Macled.)
143. Childrenite.
144. Childrenite.
145. Childrenite.
146. Childrenite.
147. Brookite.
PLATE VII.
RHOMBIC SYSTEM (Cont.)
Fig.
148. Topaz.
149. Topaz.
150. Marcasite.
151. Marcasite.
152. Marcasite (Macled.)
153. Chondrodite.
OBLIQUE SYSTEM.
Fig.
154. Chessylite.
155. Malachite.
156. Malachite.
157. Malachite.
158. Gypsum.
159. Epidote.
160. Pyroxene.
161. Pyroxene (Macled.)
162. Clinoclase?
163. Clinoclase.
164. Clinoclase.
165. Clinoclase, Liroconite.
166. Clinoclase.
167. Lunnite.
168. Valentinite, Vivianite.
169. Valentinite, Vivianite.
170. Erythrite.
171. Erythrite.
172. Orthoclase.
173. Orthoclase.
Fig.
174. Albite.
175. Albite.
Fig.
176. Orthoclase.
ANOKTHIC SYSTEM
OBLIQUE SYSTEM.
PLATE VIII.
OBLIQUE SYSTEM (Cont.)
Fig.
177. Orthoclase.
178. Orthoclase.
179. Orthoclase.
180. Orthoclase.
181. Amphibole.
ANORTHIC SYSTEM
Fig.
182. Albite.
183. Cyanosite.
184. Axinite.
185. Axinite.
186. Axinite.
187. Axinite.
HEXAGONAL SYSTEM
Fig.
188. Beryl, Calcite, Mimetite, Pyromorphite.
189. Apatite.
190. Apatite, Miraetite, Pyromorphite.
191. Apatite.
192. Pyromorphite.
193. Beryl.
194. Beryl.
195. Calcite, Chalybite.
196. Apatite.
197. Quartz, Calcite, Dolomite.
198. Calcite.
199. Chalybite.
200. Calcite, Ilmenite.
201. Calcite, Chalcophyllite.
202. Chalybite.
Plcute VM,
200
XT
Z06 ^
206
PLATE IX.
HEXAGONAL SYSTEM (Cont.)
Fig.
203. Bismuth.
204. Quartz.
205. Quartz.
206. Quartz.
207. Quartz.
208. Quartz.
209. Quartz.
210. Quartz.
211. Quartz.
212. Tourmaline.
213. Pyrargyrite.
214. Pyrargyrite.
215. Tourmaline.
216. Tourmaline.
217. Calcite, Chalybite.
218. Calcite.
219. Cronstedtite.
220. Chalybite.
221. Antimony, Arsenic.
222. Calcite.
223. Calcite.
224. Chalybite.
225. Chalybite.
226. Calcite, Hematite.
227. Calcite.
PLATE X.
HEXAGONAL SYSTEM (Cont.)
Fig.
228. Connellite.
229. Connellite.
230. Hematite, Ilmenite.
231. Chalybite, Dolomite, Calcite.
232. Hematite.
233. Hematite.
234. Anatase (Pyramidal. )
235. Babingtonite (Oblique.)
236. Cronstedtite (Hexagonal.)
237. Cronstedtite (Hexagonal.)
238. Cronstedtite (Hexagonal. )
239. Muscovite (Oblique?)
240. Muscovite ( Ob lique?)
241. Muscovite (Oblique?)
242. Pyrolusite (Rhombic.)
243. Quartz (Hexagonal.)
244. Scorodite (Rhombic.)
245. Wolfram (Rhombic. )
246. Wolfram (Rhombic.)
PlateX
ZZ8
Z33
Z46
LIST OF SUBSCRIBERS.
ACL AND, the Late Sir T. D., Bart.,
Killerton Park, Exeter.
ADAMS, WM., Cardiff.
ANDREW, JAS., St. Austell (2 copies).
ARGALL, WILLIAM, Great Huel Vor,
Breage.
B.
BANNISTER, Rev. JOHN, LL.D., St.
Day.
BARCLAY, JOHN, Falmouth.
BARHAM, CHAS., M.D., Truro.
BARRETT, CHAS., Truro.
BATTEN, J. HALLET, Penzance.
BAWDEN, Capt. C., St. Day.
BAWDEN, CHAS., St. Day.
BEARDSLEY, AMOS, F.G.S., F.L.S.,
Grange, Lancashire.
BENNETTS, Capt., Spearn Moor.
BOASE, G. C., London.
BOLITHO, E., Penzance (4 copies).
BOLITHO, W., Polwithen.
BOLITHO, W. jun., Penzance.
BONE, C. B., Redruth.
BRAY, W. J., Chace water.
BRISTOW, H. W., F.R.S., London.
BROUGHAM, Kev. M. N., Cury.
BROWNE, J. T., St. Austell.
c.
CAMBORNE WESLEYAN INSTITUTE.
CAREW, W. H. P., Antony, Torpoint.
CARNE, Miss ELIZABETH, Penzance.
CARTWRIGHT, G. K., Camborne.
CHURCH, Prof. A. H., M.A., Ciren-
cester (3 copies).
CHURCH, Rev. G. L., Chacewater.
CLARK, RICHARD, Truro.
COLLINS, Rev. C. M. ED., Trewardale
(2 copies).
CORNISH, Rev. J. R., Truro.
COURTENAY, LEONARD, Penzance.
CUNNACK, JAMES, Helston (3 copies).
D.
DARLINGTON, JOHN, London.
DAVIS, Rev. EBENEZER, London.
Dix, W., Truro.
DYKE, ED. G., St. Austell.
DYMOND, W. P., F.M.S., Falmouth.
EDWARDS, Jos., St. Day.
ELLIOT, JOHN, Liskeard.
ENYS, JOHN S., F.G.S., Enys, Penryn.
EUDEY, JOHN, Germoe.
F.
FALMOUTH, Rt. Hon. Lord, Tregothnan
(2 copies).
FALMOUTH PUBLIC LIBRARY.
FERGUSON, H., C.E., Truro.
FORTESCUE, Hon. G. M., Boconnoc.
FOSTER, C. LENEVE, B.A.,D.Sc., &c.,
Piedmont.
Fox, R. W., F.R.S., Penjerrick (2
copies).
Fox, HOWARD, Falmouth.
Fox, ALFRED LLOYD, Falmouth.
FREEMAN, J. D., Penryn.
G.
GARBY, Captain, W.S., East Pool.
GRYLLS, WM., Redruth.
H.
HALL, T., F.G.S., Pilton, Barnstaple.
HANSON, SAMUEL, Todmorden.
HARRIS, Capt. S., Gt. HL Vor, Breage.
HARRIS, JOHN, Dolcoath.
HAWKE, E. H., Tolgulla.
HENWOOD, W. J., F.R.S., F.G.S.
Penzance.
HERNAMAN, J., Truro.
HEXT, Rev. G., St. Veep.
HICKS, E. W., Calstock.
HIGGS, SAMUEL, Penzance.
HILL, F., F.G.S., Helston.
HOCKING, SAMUEL, C.E., Rosewarne,
Camborne (2 copies).
HODGE, - , Providence Mines.
HOSKING, WM., Crava, Helston.
HUNT, ROBERT, F.R.S., &c., London.
HUSBAND, WM., C.E., Hayle.
HUSTLER, the Late WM., F.C.S.,
Falmouth.
J.
JAMES, STEPHEN HARVEY, Botallack.
JAMES, Capt. A. , Huel Basset.
JAMES, S. T., Huel Rose, Scorrier.
JEWELL, Capt. J., St. Day.
JOHNSON, M. H., F.G.S., London.
LIST OF SUBSCEIBEES.
KEMP, J., Dolcoath.
KITTO, B., Breage.
M.
MUBCHISON, Sir, E.I.M.,Bart.,F.K.S.,
London.
MASEY, T. A., F.G.S., London.
MATTHEWS, B., St. Day.
MAYNARD, Capt. JOHN, East Pool.
MAYNE, JAMES, St. Day.
MICHELL, STEPHEN, St. Day (3 copies).
MIDDLETON, RD., London (4 copies).
MlDDLETON, H., Burncoose.
N.
NETTELL, M., Illogan.
NOBLE, Capt. GEO., Constantino,
p.
PENZANCE PUBLIC LIBEARY.
PEARCE, GILBERT, Hayle.
PERKIN, F., Albert Memorial Museum,
Exeter.
PETER, J. T. H., Chyverton.
PETER, I. F., Redruth.
PHILLIPS, H. L. , London.
PHILLIPS, JOHN, St. Day.
POLKINGHORNE, W., Woodlands, Par.
POPE, Martin, Carharrack.
PROUT, Rev. EBENEZER, F.G.S., Fair-
field.
PROVIS, Capt. W., Dolcoath.
PROVIS, T. B., Brazil.
PROVIS, JOHN, Cam borne.
PROVIS, Joseph, Camborne.
PRYOR, Capt. Jos., Trefula, Gwennap.
R.
REEKS, TRENHAM, Jermyn-St., London.
REMFRY, G. F., Truro.
REMFRY, H. O., Truro.
RICHARDS, Capt. T., F.G.S., Redruth
(2 copies).
RICHARDS, Capt. R., Condurrow.
RIVERS, G., London.
ROGERS, JOHN JOPE, Penrose (2 copies).
ROGERS, Rev. SALTREN, Gwennap (2
copies).
ROGERS, Capt. HENRY, R.N., Hartley,
Plymouth (2 copies).
ROGERS, Rev. WM., M.A., Mawnan.
ROGERS, REGINALD, Carwinion.
ROWE, Capt. JAMES, Nangiles.
ROYAL GEOLOGICAL SOCIETY OF CORN-
WALL.
ROYAL INSTITUTION OF CORNWALL.
RUDLER, F. W., F.G.S., London.
RUSKIN, JOHN, M.A., D.C.L., London.
s.
ST. AUBYN, Sir EDWARD, Bart., St.
Michael's Mount (4 copies).
ST. AUBYN, JOHN, M.P., Pendrea (4
copies).
SHERIFF, J. D., C.E., Truro.
SIMMONS, J., Liskeard.
SMITH, W. B., Redbrooke, Camborne.
SMYTH, WARINGTON W., M.A., F.R.S.,
Marazion (2 copies).
T.
TREVELYAN, Sir W. C., Bart., Wal-
lington.
TAYLOR, RICHARD, F.G.S., London (4
copies).
TEAGUE, WM., St. Day.
THOMAS, Capt. JOSIAH, Dolcoath.
THOMAS, C., Dolcoath.
TONKIN, Capt. JOHN, Dolcoath.
TONKIN, W. H., Pool.
TREGAY, Capt. WM., Pednandrea (2
copies).
TREMENHEERE, H. S., London (2
copies).
TRUSCOTT, — , jun., Trevarrick.
TRUSCOTT, F., B.A., Falmouth.
TUCKETT, F. F. , Frenchay (2 copies).
TWEEDY, ROBERT (3 copies).
v.
VIVIAN, A. PENDARVES, M.P., South
Wales (4 copies),
w.
WILLIAMS, Sir F. M., Bart., M.P.,
Goonvrea (10 copies).
WILLIAMS, J. M., Carhayes Castle (2
copies).
WILLIAMS, Captain R. H., C.E., St.
Austell (4 copies).
WILLIAMS, H. , Alma, Truro.
WILLIAMS, A. Alma, Truro.
MR. BRISTOW'S DICTIONARY OF MINERALS,
In crown Svo. with 486 Figures on Wood,
price 6s. cloth,
A GLOSSARY OF MINERALOGY.
By HENRY WILLIAM BRISTOW, F.G.S.
Of tJie Geological Survey of Great Britain.
THIS work embraces the physical
characters and chemical composition
of all the known metalliferous and
earthy minerals, with a concise and
popular account of their history and ap-
plication. An alphabetical form has been
adopted, partly owing to the want of
agreement between various Authors with
regard to the classification of minerals,
and the practical inconvenience of a
purely chemical arrangement, and on some
other grounds, amongst the rest simplicity
and facility of reference. The Author has
purposely avoided the production of a
systematic treatise, but has endeavoured
to provide a handy book for general use,
available by any traveller or other person
unacquainted with the sciences of Minera-
logy or G-eology, who may desire to ascer-
tain something of the properties, uses, and
characters of the minerals with which he
may meet. With this view, a plain and
intelligible account of the external and
physical characters of the various minerals
is given (generally under the English
name of each), and illustrated by 48G
woodcuts representing their most common
crystalline forms. These figures of crys-
tals have all been carefully drawn on
wood, expressly for the work, by Mr.
J. B. Jordan, and cut by Mr. S. J. Mackie.
The formulae denoting the chemical com-
position of the minerals (on the supposi-
tion of their being free from extraneous
matter) are followed by analyses showing
their composition as they ordinarily occur
in nature. The action of blowpipe and of
acids upon each mineral is fully described.
Particular attention has been bestowed on
the lists of localities both abroad and in
the United Kingdom, and the latest dis-
coveries are mentioned in their proper
places. All these materials have
been carefully brought up to the
present time. The derivators of the
names of the various minerals arc-
also given ; and an account is added of
their history and application, and of their
uses in the arts and manufactures.
The introduction of a copious list of
French and German synonyms will, it is
believed, prove of great assistance to the
English student in reading the works of
foreign authors, and will also render the
book a useful travelling companion to
persons visiting museums, whether .at
home or abroad, or studying mineral
collections in private cabinets, according
to whatever system these may happen to
be arranged. In the INTRODUCTION the
terms made use of by mineralogists are
fully explained, as well as those employed
by lapidaries and jewellers. The modes
of distinguishing minerals are pointed out,
and the use of the blowpipe and of acids
in effecting that object is described in
detail. In order to enable persons to
make a systematic arrangement of their
own collections, a simple and easy mode
of classification is given in the Introduc-
tion, accompanied by a copious list of
minerals arranged in their proper order in
conformity with it.
In hope of facilitating the studies of
those who may be desirous of examining
the minerals in our national collections
with the book in their hand, and of com-
paring the printed descriptions with the
specimens themselves, references are given
(when practicable) to the Cases in which
each mineral may be found, both in the
British Museum and in the Museum of
Practical Geology.
London : LONGMANS and CO. Paternoster Row.
MR. BRISTOW'S DICTIONARY OF MINERALS.
OPINIONS OF THE PRESS.
* THIS is really a handy book.
A concise account of all known
minerals is given in alphabetical
order, and references are added to
the cases in which specimens may
be found in the British Museum and
the Museum of Practical Geology.
There is also a useful introduction
on the characters, properties, and
chemical composition of minerals.'
MEDICAX TIMES and GAZETTE.
' WE can recommend Mr.
BRISTOW'S Glossary of Minera-
logy to all geologists, as well as to
mining students, and the cadets of
Sandhurst and "Woolwich. It is a
real handy book ; the arrangement,
being alphabetical, is suited to every-
one's capacity As a work of
general utility, this book is the best
of its class, and the only one we
should ever think of opening by
way of amusement. We refer to
such articles as arsenolite, amber,
asbestos, asphalt, avanturine, &c.
or to that on the diamond.'
CHITIC.
1 THE student in physical
science has long desired a book
combining facility of reference with
a concise and familiar account of all
the known minerals. This want is
now fully supplied by the present
work, which is not a mere glossary,
as its title would imply, but is in-
termediate between it and a manual.
The first fifty pages contain a de-
scription of the general characters
of minerals, their various proper-
ties, composition, and classification ;
whilst the Glossary professes to give
information upon every known mi-
neral substance, and this informa-
tion is as complete as the present
[ state of our knowledge will
allow The Author's task
has been ably executed, and his
work will be much in request.'
LANCET.
'* THERE has been hitherto no
work in English at all answer-
ing to this Glossary of Mr. BRISTOW.
It is a Dictionary of Mineralogy of
the most complete kind, and yet in
the most portable form, and must
become a sine qud non to every
practical mineralogist. Unencum-
bered with any system of classifica-
tion, it describes every mineral
species or variety alphabetieally,
with reference to synonyms, Eng-
lish, French, and German. The
description of the minerals is at
once concise and yet sufficient for
practical purposes. It includes their
crystalline and physical character-
istics, chemical composition (shewn
both by formula and analyses), be-
haviour before the blowpipe, and
their principal localities and us~es.
It need scarcely be said that Mr.
BEISTOW, having the resources of
the Jermyn Street Museum at his
hand, as well as the assistance of
so eminent a mineralogist as Mr.
WARINGTON SMITH, has had great
opportunities of turning out a good
book. And he has certainly done
so Notwithstanding the great
body of information it contains,
this little volume has the advantage
of extreme clearness of type and
great portability. For tourists and
practical men interested in minera-
logy it will be indispensable; among
the former we expect Mr. BRISTOW'S
green book will be seen, often side by
side with Mr. MURRAY'S red volumes.'
MINING and SMELTING MAGAZINE.
London: LONGMANS and CO. Paternoster Row.
16 7734
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