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BRITISH MINERALOGY:

OR
COLOURED FIGURES

INTENDED. TO ELUCIDATE

THE MINERALOGY

OF

Great Mritaiir.

BY JAMES SOWERBY, F.L.S.

HONORARY MEMBER OF THE PHYSICAL SOCIETY OF
_GOTTINGEN, :

DESIGNER OF ENGLISH BOTANY, AUTHOR OF
ENGLISH FUNGI, ETC,

(With Assistance.)

As for the Earth, out of it ccmeth Bread, and under it is turned up as it
were Fire. The Stones of it aré the Places of Sapphires; and it hath
Dust of Gold. Jog xxviii. 5, 6.

VOL. IV.

LONDON:»
PRINTED BY
RICHARD TAYLOR AND CO., SHOE-LANE, FLEET-STREET 35
And sold by the Author, J. Sowersy, at No. 2, Mead Place, Lambeth:

and by Wuire and Co., Fleet-street; SHerwoop and Co.,
Paternoster-row; and all other Booksellers.

MDCCCXI,

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THE fluctuating state of Mineralogical knowledge makes
it commendable to postpone the Systematic Index that
might be expected to this Volume. It is therefore proposed
to give a general Systematic Index to the whole work, at
the end of the next volume. In the mean time, I beg leave
to say, that I have published the First Part of a Catalogue .
of British Minerals for public Criticism and Amendment ;
that it may be made by more help and experience—more
complete. This part contains the Combustibles and Earths,
with the specific names of most of the Exotic Minerals.
which are not known to this Country, to show their places
in the System. The British Minerals have references to

British Mineralogy and Habitats, &c.

Miioo- Ae

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301

feb 1 1809 Publish by Ja” Sowerby London

AWB. CCCI.

CUPRUM sulphureum.
Sulphuret of Copper ; Swimming Pyrites.

Div. 2. Imitative.

Ir is now no novelty to find Metals of very light specific
gravity, since Mr. Davy’s discovery of Sodium and Potassium,
yet we have no account of Swimming Copper Pyrites, that
I know of. I am therefore glad to treat the world with
this novelty. Some time ago Mr. Carne favoured me with
the Swimming Quartz which had some porous Sulphuret
and Oxide of Copper about it, which gave me reason to
suppose some Swimming Copper Ore might be found,
since which time he has kindly informed me that he has —
procured a specimen, and I have, by chance, received this
from the same place *.

It would seem from its appearance to have been formed by
passing among the irregular interstices of some shattered
part of arock which is completely gone in the same manner
as from the Quartz above. It is in somewhat plated
chambers irregularly angular of various dimensions. It is
extremely friable, and the tenuity of the plates or divisions
will scarcely allow of its being handled. It is a kind of
exception to the rule by which we judge of the specific
gravity or weight of Metals by the hand, to distinguish.
them from the Combustibles and Earths, and is a good
example of an argument regarding the gravitating principle,

* From Trelistian Mine, near Penzance in Cornwall.
VOL. IV. B

$

that, under certain circumstances, the Metals may lie above
the. Earths and Combustibles, when in a divided state.
Thus it is lighter than water in this porous form, although
its solid specific gravity in comparison to that of Water is
as 4°315 to 1000: so that, in judging of specific gravity,
the solid state of the substance must be attended to.

wise

ay
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poe Rhea x

Feb.1.2b09.Publish a by dat Sowerby Londen -

TAB. CCCII.

CUPRUM_ hyperoxygenizatum.
Peroxide or Hydrate of Copper.

Div. 3. Amorphous.

As it is interesting to Geologists to see what substances
come together, I figure this variety of Copper Ore mingled
with the black Oxide of Manganese in the same bed or
part of the vein. It is extremely curious to find it so clean
and bright among the loosely cracking, almost powdery
Manganese which is so liable to soil any thing near it.
Nature, here, however, shows us a striking example of
the inseparable connexion between the particles of certain
substances, so important to defend us from that chaos
which might otherwise ensue.

This is a variety of the same Copper Ore as ¢abs. 279 and
280, containing much Silex, and, having most of the different
appearances, as to colour, from nearly white to yellower
and blueish green, probably depending on the quantity of
water it holds. The dark green parts. are Carbonate of

Copper.

50.

)

Lond.

Jat Sower’y

Feb.2.2800,Publish@ br

Cr

TAB. CCCIII.

-. CUPRUM $s arseniatum.
Arseniate of Copper.

Class 3. Metals. Order 1. Homogeneous,
Gen. Copper. Spec. Arseniate of.

Iw addition to our former figures of Arseniate of Copper,
tals. 168, 169, 170, I am happy to figure these curious
varieties, not merely because they are rare, but as examples
that are of more consequence, as they will explain many
groups of this substance that are scarcely, if at all, under-
stood. The present rotate specimens, if I may so call
them, are, as it were, a congeries formed of the truncated
triédral column, chiefly like the left hand bottom outline.
The other outline shows, by the small dots, that one of the
solid angles is sometimes replaced by a new face, which
would give it a wedge form, very applicable to the rotate
formation of the upper specimen: they, however, seem
more perfect columns, and are placed among each other
somewhat upon the principle of the Galena in tab. 131.
The middle outline shows the columnar sides and the tri-
angular ends, nearly as they appear when magnified. Some .
are very small, and others larger and more irregular, some-

what approaching the broad faces, and even the mackles,
as in the next figure.

TAB. CCCIV.

A\r first sight this looks like a very different modification
from the last. It is, however, only more perfectly accu-
mulated on the periphery of a wheel, as it were, united
in large faces, either upon opposite ends of crystals, like
ihe right hand lower figure, or mackle, and is sometimes
formed of a variety composed of many, partly belonging
to the left hand bottom figure. The ends become small
and rough around the series of tab. 303, but large and
smooth around this; whilst, on the contrary, the radii of

the latter or column are generally most confused,

Feb.23509, Publish a by Jas dowerby London.

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9

TAB. CCCV.
CALX carbonata.
Crystallized Carbonate of Lime.

Class 2. Earths. Order 1. Homogeneous.
Gen. Calx. Spec. Carbonata.
Div. 1. Crystallized. Var. Hexaédral Prisms.

Syn. Chaux carbonatée prismatique. Haiiy, 2. 141.

Tue simple hexaédral column is among the scarcer forms
of this substance in Britain.

The present specimens came from Cumberland. Crys-
tals of this form more rarely occur in Derbyshire. In
Scotland they are found at Strontian with Stilbite on the
opposite side of the specimen, as figured at tab. 258. In
some instances the whole form of the crystals is very neat,
and every face is polished.

The upper specimen has not the end face polished, but
roughish.

The lower specimen is most extraordinary, as on it the
crystals have very short columns and lie in various di-
rections, having both ends opaque, but are smooth and
polished on all the faces. The cause of polished faces
might seem to depend upon the gradual separation of the
menstruum or solvent from which it crystallized; and a
great quantity might, by suddenly passing off, leave the
terminations of the crystals rough as in the upper specimens,
which are not finished at both ends ; the lower crystals
probably derive their opacity from a scanty supply of
water of crystallization at the ends.

Some of the crystals in the upper specimen have the ter-
minal edges bevilled towards the column which leads to
other formations—see the next figure.

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TAB. CCCVI.

CALX _ carbonata.
Carbonate of Lime.

Class 2. Earths. Order 1. Homogeneous.
Gen. Calx * Spec. Carbonata.

Div. 1. Crystallized. Var.

EE

Tu present modification is far from common, and has
so peculiar an appearance that it must attract the obser-
vation of the enlightened enquirer, showing how infi-
nitely various may be the modifications of this substance.
The edges of the three sides of the column are rounded
by repeated facets on that and on the pyramid, and the
other three sides of the column are bevilled laterally to-
wards the former three, making with them and the pyra-
mid a figure like the front of a Gothic arch. The thick-
ness of the column, and depth in the proportions of the
flatter, or rounding, facets, give this a variable appear-
ance. The pyramidal ends are often distinct, and nearly

correspond with the primitive rhomb.

306

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April 1 2809 Publishd by Ja” Sowerby London

ii

TAB. CCCVIT.

SILEX Quartzum, var.
Octaédral Calcedony.

Class 2. Earths. Order 1. Homogeneous.
Gen. 4. Silex. ~ Spec, Quartzum.

Div, 2. Imitative. Var. Octaédral,
Syn. Quartz Agathe. Hauy, 2. 424.

T was favoured with this fine specimen by Lord Heath-
field, who sent it from Beer Alstone in Devonshire. It is
a secondary crystallization, having taken the form of songe
other substance that was priorto it. It has here taken the
place of Fluor or Galzena, most probably Fluor somewhat
like that of tab. 26. Some of the casts are extremely neat,
others are somewhat hollow, and haye Quartz crystals

within them,

(ond

TAB. CCCVITII.

Cubic Calcedony.

Tus is commonly called Cubic Hornstone, but is truly
a Calcedony, as indeed are many things which are com-
monly called Hornstone, and it is hard to show their di-
stinguishing characters. This specimen came from Beer
Alstene, where the curious Octaédral Fluor is found on
what is also called Hornstone—see tab. 26. The crystals are
generally blunt edged, their solid angles truncated, and their
surfaces minutely mamillated, which helps to. distinguish
them. This secondary crystallization almost exclusively
belongs to this substance, although there are one or two
instances of its being found in other substances, as in
Steatite, but which is chiefly in the form of Quartz. All
are scarce.

The name Hornstone I suppose to be taken from the re-
semblance the stone hears to horn; a great variety of stones
have occasionally had that appellation given to them, which
probably vary much in their ingredients, as some little
mixture may help their appearance: thus we might possibly

find Lime, Fluor, and Clay Hornstones.

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April x i809 Fubliskd by Ja’ Sowerby London

TAB. CCCIX.

SILEX Quartzum, var. Stalactites.
Stalactitical Calcedony.

Div. 2. Imitative. Var. Stalactitical.

Syn. Quartz Agathe. Hauy, 2. 424.

‘Trevascus in Cornwall has afforded the finest examples
of this peculiar Stalactitical Calcedony. My liberal friends
the Hon. Charles Greville, Philip Rashleigh, Esq. and
Mr. Richard Phillips can show truly magnificent spe-
cimens, above a foot in diameter in some parts, and of |
every varied form, including the following examples.

The upper figure serves to express the more usual stalac-
titical formation, and the somewhat undulating mamillated
appearance common to Calcedony, besides the blunt,
heavy, and inosculating varieties.

The lower figures show what is commonly called Bony
Calcedony, and have some of the usual appearances ac-
companied by the more unusual ones of slender thready
plates, forming the foraminous appearances which dis-
cover to us something more than what is merely stalacti-
tical, and peculiar to the substance itself; probably de-
pending on the nature of the solution, like most Flints
and flinty substances; but it never crystallizes as they
do, having that appearance only because it has been

cast into the places where crystals haye been.

14

TAB. CCCX.

SILEX Quartzum, var.
Shell-formed Cs

Div, 2. Imitative. Var. Shell-like.

Tau obliged to the generosity of Mr. Milne of Fonthill
for this Spec imen. That place and the neighbourhood often
afford Cornua Ammonis of very y extraordinary dimensions.
I was told of one that was at Tisbury nearly ag big as the
Jargze wheel of a coach. I have one ef 21 inches in diameter,
and my friend Mr. W. Cunnington has one larger, They
are often of Sandy Limestone, or Limestone w ith crystals
within, and now and then there are found the remains of
stmilar shells in Flint with the chambered divisions paftly
caicedonized, if I may use the expression, and containing
Quartz crystals; but the most curious specimen ever seen
is the present, except one as nearly like it as possible,
which I am told is in the possession of Sir Edward Hulse
of Salisbury. It is perhaps as extraordinary a geological
specimen as any that have been seen. The mass is
chiefly Flint; but the shell has been lined, and having’ sub-
equently decayed, left the Calcedony of ‘the. most delicate
and exquisite structure. <The peculiarly regular folding
manner of the divisions, and their uniformity, : are no where
disturbed. The Caleedony is placed distinctly around
where the shell originally was. There are other minute
shells about the specimen, and also some Carbonate of
Lime, both crystallized and amorphous.

The lower figure exhibits one of the partitions, showing
the tube which passes round the shell, different from what
is usual, as not being a continued channel, but divided into
short tubes, each ot which communicates by its openings
with two chambers.

Geologists, as they contemplate the changes which have
here taken place, may well join with David, Linneus, and
all true philosophers, in exclaiming, * Oh! JEHOVAH,
great and manifold are thy works in wisdom hast thou
made them all; the Earth is full of thy riches.”

Sir H. C. Englefield showed mea beautiful specimen of a
spiral shell with the end passing from Calcedony to Opal.

2h O

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April 1 1809 Publishd by Ja” Sowerby London

3S/

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TAB. CCCXI.

STRONTIA sulphata.
Stellated or radiated Sulphate of Strontian,

Div. 2.- Imitative,

Ts elegant variety of Sulphate of Strontian was found ia
sinking a foundation for buildings at Bristol. I do sot
know that such has been met -with elsewhere. Besides
these stellated ones, there were manv very beautifully spicu- |
lated. The noble appearance of this, relieved so conspi-
cuously, being formed over Metastatic Carbonate of Lime,
enhances its curiosity. The stellz or radii so much repre-
sent those in general executed by sculptors, that we might
imagine they had had some such an original to imitate ;
and as, { believe, they borrow from antiquity, so I should
imagine the antique models are borrowed from something
in Nature, which indicates that the ancients were not only
eapable of taking a proper advantage of what was useful or
instructive to them, but that they probably paid much at-
tention to such subjects, and were not at a loss for originals
to facilitate their study, and help their inventions.

This substance is described at tab. 117, and in form
much resembles the Lepastrum or Stellated Sulphate of

Barytes—see tal. 173.

16

TAB. CCCXIT.

STRONTIA sulphate.
Brush-like Sulphate of Strontian:

Bausu Iron Ore is spoken of in many authors, but I do
not know of any mention having been made of Sulphate of
Strontian in that form. The specimen here figured, how-
ever, 1s so perfectly described by that appellation, that very
few will not assent to it. It came from the same place
as the last, and is formed altogether of smaller spicule.
The bundled and, sometimes, twisted elongated arrange-
ment admits of not only a picturesque effect, but exhibits
the pleasing graceful line of beauty so universally attractive
in Nature, that, ever since our Hogarth observed it, we may
he said to have been indulged with a new sense for abstract

beauty,

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Apri 1 1809 Publish ty Ja” Sowerby London

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17

RAB, COCKIL

CARBON . vegeto-bituminosus.
Vegetable Coal.

Class 1. Combustibles. Order 2. Compound.

Gen. 5. Carbon. Spec. 2. Combined with bie
tumen and a small portion
of vegetable matter.

Div. 2. Amorphous.
Syn. Bituminous Schistus. Hatchett in Linn. Trans.
4, 136.

-

Kimmenipee Coal, as spoken of by Mineralogists, is ne-
vertheless not very generally known, nor would the sub-
stance, if found in any other place, from its aspect, be
suspected as a Coal, and therefore has been casually over-
looked by those who wanted specimens. It varies some-
what in appearance, as it sometimes divides with a very re-
gular schistose fracture, and it is at other times more
massive and earthy. The same is found a little above the
level of the sea on the eastern side of Portland Island, as
well as at Swanage in Dorsetshire, where itis met with at
the same level. It is used at Swanage, and in some parts
of Portland, for heating ovens; and although the Bitumen
gives an uncomfortable odour if burned in a common fire,
it does not, I am told, give any effluvia to affect the bread
in the oven.

It may be known by its lightness, and taking an easy
gloss with rubbing the nail over it; but more particularly —

VOL, III. D

18

by its strong blaze in a common fire. It is sometimes sold
for a guinea per ton, and is often in large broad masses,
three or four feet in diameter. It is also sometimes dug
from the rock with a clay shovel.

The upper specimen 1s somewhat slaty in fracture, though
rather more earthy. It is a softish clayey Shale with much ,
Petroleum, and emits the smell peculiar to the latter sub-
stance when heated.

The lower specimen is still more earthy, but somewhat
fissile, and is, as it were, interrupted with regard to its
parallels by partly curving round an irregular ball of earthy
Pyrites. It is a curious specimen ;—sometimes Carbonate .
of Lime or Chalk intervenes, which is soft. Many other
varieties occur, some of which are more slaty, some more
earthy, and others of different colours.

The Isle of Wight, opposite Alum Bay, affords Bitu-
minous Carbon in great variety. My kind friend Mr. Lyell
favoured me with some that seems to point out the progress
of the Bitumen passing from the vegetables and im-
pregnating the substances near them. Liancolnshire affords
a similar substance, with Lime of shells remaining betwixt
the laminz. I have some sent me by the Rev. R. B. Francis.

A mixture of Bitumen with Lime, Clay, &c. is some-
times found in Essex, nearly resembling this. I have been
favoured with it by Colonel Walford.

J Sowerly; Mead Place.

by

lished

Apr. 1,18 09, Tub

19

TAB. CCCXIV.

CALX carbonata, var. metastatica.

Metastatic crystallized Carbonate of Lime.

Div. 1. Crystallized.

EEE

Tuts noble specimen of crystallized Carbonate of Limeis
curious, as a variety leading to a kind of Mackle that does
not seem to have been suspected ; but is not rare as to its
formation, for we often see ordinary specimens that partake
of it, having two of the opposite faces of each pyramid
much widened, forming a base to each parallel to the edge
of the primitive nucleus: this will be seen in the next
figure, which may be compared with éab. 33, the usual Meta-
static Mackle. The two facets, fig. 1, are primitive, and fig. 2
are the same as those of tab. 34, dower figure, equiaxed ;
but having those very obtuse-angled faces that so often
produce a rounding form, which help so much in the
humerous varieties of crystals in this substance, and are
extremely curious. vg. 3 is a somewhat rounded edge
nearly on the angle of the pyramid. The facets, fig. 4, and
that opposite, are of the hexaédral column. = Frig. 5, a facet
nearly on the edge of the nucleus.

The rounded facets in Crystals are sometimes very de-
ceiving ; and the comparing this with the next plate will
prove the necessity of this leading specimen, which shows
the dividing angle of the natural face of the pyramids
parallel with the primitive edge, that divides the two pri-

D&

20

mitive facets at 1. 1. A little rounding face on the acute
angles of the broader planes of the pyramid towards the fa-
cets of the prism, jig. 4, alters the parallelism of the edges, so
that by turning round the two halves, as in the next figure,
is formed the puzzling appearance so proper to be cleared up,
on: account of being totally new in Crystallography, and
extremely curious.

This noble, beautiful, and singular Crystal is from Derby-
shire, and is so suitable to precede the next figure, that I
thought it quite proper to place it here, though indeed it is
only the metastatic formation, as in fab. 353 but the
breadth of two of the faces would disguise it to many,
and more so if mackled as in the next figures, with the two
faces still broader, and which this happily serves so clearly
to elucidate, and, by the illinitions of the fractures, helps.
to point out the mutual base of the mackling parts; which
is, I believe, both new and extraordinary, as it coincides
with a plane drawn through the longer diagonal of the
primitive rhomb.

Its colour seems clearly to depend upon the Oxide of
fron, which is partly mixed and partly chemically com-

bined.

ILD

June 1 1809 Publishad by Ja” Sowerby London

21

TAB. CCCXYV.

Tue present curious production is one of those things
that few can expect to possess; therefore it is, like many
others in this work, a pleasant proof of the utility of ficures,
which is certainly next to the possession of the object, as to
the instructive information it gives, and the making public
those beauties of Nature that must otherwise be ever lost
to the scientific world.

I do not know that this formed Crystal has yet been
spoken of: Romé De Lisle and Haiiy do not mention it.
It is in the shelly Limestone which forms one of the upper
strata of Derbyshire that this has been formed, hid from
mortal ken, within one of the most remarkable species
of shells I ever knew, Conchyliolythus productus of Mr.
Martyn’s most ingenious work, plate 22. f. 1, 2, 3.

The reason why the primitive molecules should so form,
remains a desideratum. We have but just cot a notion of
the subject, but diligence in this discovering age may yet
learn more of Nature’s ways, and even this may be the
leading cause: the equally contrariwise attraction of the
particles may be governed by the equal evaporation of the
fluid in contrary directions, and the gravitation of the sol-
vent medium may poise them to that angle which so nicely
replaces them.

One great curiosity of this Mackleis, that the lateral notch

22

at the junction of the two halves at the upper end of the
column is very deceiving, being formed from somewhat
rounding facets, often scarcely discernible, but by these
means become more conspicuous—see the last description.

This specimen was lent me by my friend Mr. Lowry,
who met with it last summer, and first discovered this
remarkable Mackle.

It is prettily placed in the hollow of the shell among
the Limestone, which has on the left hand somewhat en-
veloped the mineral pith, and crystallized about the bub-
bles.

310

J

June 2 18¢c9 Publishad by Ja” Sowerby London

23

TASB. CCCXVI.

CALX carbonata, var.
Carbonate of Lime.

Dw. 1. Crystallized.
Syn. Chaux carb. analogique. Hazy, 2. 252.

EEE

Common things are often esteemed by common persons
because they look brilliant, and Quartz and Mundic have
been thus vulgarly called Diamonds; and Diamonds in
themselves of real value, in rude fragments, without a
proper knowledge, might be cast away as rubbish. It is
so lately that the instructive lessons of Nature have been
consulted on the useful and elegant study of Mineralogy,
that those who have taken advantage of this growing know-
ledge only know the benefit of it; they can appreciate
what is to be esteemed valuable; they enjoy that eminence
that sanctions a due value on what is most explanatory of
true science.

The present specimen is very rare and valuable; it shows
that the attraction that brings two crystals regularly together
is confined to one particular side, and not disposed around
the apex of the nucleus, as in the common Mackles ; and
it is new, as it is connected with the columnar modification ;
for we do not know that the columnar crystals of Car-
bonate of Lime have been mentioned as mackled in any
publication before, except the Count de Bournon’s ela-
borate Treatise, plate 24, fig. 388.

Mr. Hewland, who possesses this crystal, sets an addi-

24

tional value upon it, as it was a favourite of his late uncle
Mr. Forster, and was given him by the late Right Hon.
Charles Greville, in whose collection is the only one known
besides. It was an unfortunate jealousy in Romé de Lisle
that hindered its being published long since in his work as
an extraordinary production. I hope such pitiful jealousy
will no longer be an obstacle to the elucidation of science.

f to deli |
vo: ae ( it

317

25

TAB. CCCXVII.

CALX carbonata.
Carbonate of Lime.

Div. 1. Crystallized. .
— EEE

Mneratocicat Nomenclators have given titles to crystals
under various circumstances, such as Mackles or Twins;
and I have exhibited crystals upon crystals which might |
have some corresponding or expressive term. The present
is peculiar as to its structure, and is as it were seamed, and
although now perhaps newly noticed, is certainly of as much
consequence as many others, especially as it will furnish
two very instructive and useful examples in Crystallography,
which captivates the fancy so many ways. Here is a
half of the Metastatic * Crystal covered on the three obtuse
angles of the pyramids by a thick coat spreading on either
side, till 11 meets nearly on the acute angles, forming upon
-them a plane with a line or seam in the middle of it, which
makes the modification more conspicuous, at the same
time it is helped by a difference in the inner crystal, which
is somewhat more opaque and whiter than the outer cover-
ing; and in many lights we see the white reflection between
the two surfaces. The three varied quadrangular faces are
belonging to the common prism of this substance; those with
the seams form somewhat rounding curved truncations to

® Metastatic means the transposition that happens of the angles of the
pucleus on to the secondary crystal.

26

the three solid angles of the pyramid ; the terminal faces are
those of the equiaxe and primitive.

The lower is a group of nearly the same nature with the
seams, if I may so call them, more closed, except in
some places where there are small crystals formed, so as to
appear as if bursting out of the cover, on which the py-
ramids rest, or from which they are a continuation. |

The lower part of the upper figure has the nucleus very
distinctly in its place, and the diagonal fracture is very
distinct, and serves to show the base of the pyramid. The
Earl of Dartmouth brought me some opaque Limestone
from Lord Dudley’s mine with these fractures very distinct.

JLE

erby, Mead Place.

j

Ji

pr; 1,1609, Publishd by

bo
=~!

TAB, CCOXNV ELL

SILEX Quartzum, cryst.
Crystallized Quartz.

Div. 1. Crystallized.
$$

I prac this as a most curious example of Quartz new to
the mineralogical writers, the six vertical edges of the co-
iumns of the crystals being truncated, doubling the num-
ber of the faces, as well as those of the pyramid, which
also show the manner of the nuclei accumulating to form
various sportive modifications ; and some of these plates
meeting in seams, as I have called them, tab. 317, di-
stinctly show their nature. Another curiosity attached to
this group is a rotate accumulation of the columnar garnet-
formed Carbonate of Lime, or perhaps Magnesian Pearly
Spar.

Dr. Turton has long deserved my best acknowledgements,
as well as those of the public, not only for his literary ta-
lents in the translation of Linneus’s Systema Nature, but
in his other endeavours to assist in the general knowledge
of Natural History ; nor does he omit to collect specimens
that are useful to those engaged in pourtraying any parti-
cular branch. Among many other kindnesses I am glad
to acknowledge the present most valuable specimen, for its
novelty and very instructive formation. I should think it
were a loss to the public, in a work that is to serve in many
instances instead of an expensive cabinet, to omit the whole

28

specimen, although more really valuable than glaring ; and
besides, a book of crystals merely cannot be so valuable,
and can convey no idea of the specimen it was taken from,
and which it ought to elucidate.

The right hand middle figure shows the Quartz crystal
magnified, and the left hand one shows a crystal detatched
from the group of Garnet-like crystals of Carbonate of
Lime.

The Quartz is extremely rich externally with iridescent
colours; but this is lost in smallness.

&

9 circa a

809 Published by J. Sowerly Mead Place,

June,z1

29

TAB. CCCXIX.

STRON TIA sulphata.
Stellated Sulphate of Strontia.

Div. 2. Imitative.
ee

Turs is rather a geological specimen, and may be useful
as an example of the black rock of Bristol, with the hol-
low showing Carbonate of Lime, Fluate of Lime, and
Sulphate of Strontian, and the rocky mass or gangue is
in this instance of the same formation as that of Derby-
shire, dark Limestone, and like that is a variety of Stink-
stein holding entrochi, shells, &c., as the present spe-
cimen does: it is also analogous to that of Ireland. Having
thought it more essential to figure the substances, that they
may be known first, it may be presumed I need but in a
few instances repeat them in the form of rocks, as the
gangue in many instances, or the whole in some, form
the rocks already, as the Micas and Feldspars in Granite ;
the Analcime, &c. in other rocks.

I was favoured with this specimen by Mr. Herbert, a

very ingenious collector, of Bristol.

ha ssi ee ie lait bined so ia agli:

re veer ete our

Wares i das

ar ae Tt Miots b bene 7 a es i ‘i pd ’ @ his pe
} iy RE qo sic wit”

x
E~
aut

Juner21b04,FPublisha by Sowerby, Loniion .

31

TAB. CCCXX;
SILEX axinimorphum.

Violet Schorl, or Thumerstone.

Class 2. Earths. Order 1. Homogeneous.
Gen. Silex. Spec. Thumerstone.
Syn. Schorl violet. Journ. de Physique, 1785, Janv.

p- 66.

Schorl transparent lenticulaire. De Lisle, 2. 353.

Yanolithe. Lametherie, Sciagr. 1. 287.

La Pierre de Thum, ou Le Thumerstein. Broch.
1. 236.

Thumerstone. Kirw. 1. 273.

Axinite. Hauy, 3.22. Karst. p. 22.

[ po not know of this substance being found in Great
Britain, excepting in the parish of St. Just in Cornwall.
It is found in many places abroad, as in Siberia, Norway,
Dauphiny, and at Thum in Saxony, whence its name
Thumerstein, it having been first discovered at that place.

We find it crystallized in very oblique rhombs—see the
right hand lower figure. Its primitive is a rhomboidal prism,
similar to that of the Sulphate of Barytes—see the left
hand figure. It is mostly of a dull purplish colour, whence
its name Violet Schorl; though it is sometimes blueish,
brownish, or grayish.

In all the British specimens the crystals are confusedly
grouped and small, the foreign ones being often as large as

32

the geometrical outlines. The fracture is small, rather irre-
gularly conchoidal, and has aglassy appearance. Thumer-
stone is more or less transparent, breaks easily, is rather
brittle, may be scratched with difhculty by a knife, and
melts easily without addition by the blowpipe into alightish
green glass. Spec. Grav. 3*113—3-300.
Analysis by Vauquelin :

SHU PME eis: om eimmeec eile

Aamnme: (i iow). ee eee nee

d Wha uyeteaneeey HenRiey We op benvies pagan 11 (0)

Oxidevot Irons.) . se

Oxide of Manganese . 4
Toss Se ce ee 1
100

The crystals are found in hollows in an earthy matrix of
itself, often having a fine Asbestus covering them which
looks like Clay, but may be easily detected by being
wetted, as it is composed of extremely fine fibres. I find
also some crystallized Carbonate of Lime with the
rhombic fracture.

I am obliged to Mr. Penneck, Mr. Trevillian, and
Mr. Rashley, for specimens.

F21

lishell by J Sowerby, Mead Place.

Aug.1,1809, Pub

33

TAB. CCCXXI.

CALX carbonata, var. magnesiata.

Magnesian Carbonate of Lime with Iron.

Div. 1. Crystallized.
Syn. Sidero-Calcite. Kirw. 1.105.

‘Tuts curious Mineral was long since in Mr. W. Day’s col-
lection, and I have had specimens sent me by P. Rash-
leigh, Esq. from Tincroft in the parish of St. John, Corn-
wall, as well as by another friend from that neighbourhood.
All are related to each other in the form of their crystals,
and instruct us in a series of modifications upon an acute
rhomb; showing some very distinctly, and the manner of
accumulation necessary to form others: a very natural les-
son in Crystallography. In the upper figure are some mi-
nute perfect rhombs, resembling Haiiy’s contrastante var.
of Carbonate of Lime—see the bottom left hand figure ;
while others are larger with the three faces of the primitive
remaining on the acute points or pyramids.

The middle figure shows a small truncation on the apex
of the rhomb, forming a triangular facet, which in some
Crystals is enlarged so as to cut off the obtuse lateral angles,
thus producing hexangular faces at each end. The next
magnified figure to that on the right hand shows an accu-

VOL, IV. E

34

mulation of flat or plated rhombs, forming truncations upon
all the edges. The other figure shows them produced very
widely, with the sharper angles accumulating in a triangle
at both ends. This is exemplified in the lower part of
the specimen fig. 2. The Crystal in the middle geome-
trical figure is also on a large specimen that was in Mr.
W. Day’s collection. ee

This is the Braunspath of the Germans; but has, how-
ever, been sometimes taken for a Tin Ore in Cornwall.

Mr. W. Day observed that it did not effervesce with acids.
It is one of its characters, as a Magnesian Iron Ore, to -

effervesce very slowly.

cer Wh

bo

TAB. CCCXXII.

CALX carbonata, var. dodecaédra.
Dodecaédral Carbonate of Lime.

Div. 1. Crystallized.
ee

Narurez, ever instructing us with useful lessons, at first
sight often puzzles us. I had long since seen Quartzose
mixtures cast, as it were, over tabular Sulphate of Barytes,
forming a very accurate mould of them, small or large.
Such are commonly called Hacked Quartz, irom the no-
tion that they resembled a substance partly chopped or
hacked with a hatchet or sharp instrument; and taeir for-
mation was long left unaccounted for.

It is not uncommon to find Quartz moulds, if I may so
call them, of the Cubic Fluor*, on which it often forms,
coats; and I have a very curious specimen of white semi-
opaque Quartz having formed over the Metastatic Carbonate
of Lime, from Polgooth in Cornwall, with which I was
favoured by Phil. Rashleigh, Esq.: but I had not seen Car-
bonate of Lime forming the mould of Sulphate of Barytes
till very lately. I received it from Alstone Moor in June,
1809. The specimen represented in the figure is crystallized
in the equiaxe form; and I had another specimen sent at
the same time, which was cast over larger Sulphate of Ba-
rytes, crystallized in dodecaédrons with rhomboidal faces—
see tab. 128—which is very rare: but a still rarer form is

* Sulphuret of Iron often forms a mould fram Cubic Fluor, &e.
E2

36

when truncated at the edges, as they are in the specimen
spoken of—see the right hand outline.

It is a curious lesson in the study of Chemistry to search
for the menstruum in which the Sulphate of Barytes may
he dissolved without hurting the Carbonate of Lime; for it is
too much undercut, as the workmen would say, to deliver
the cast whole; and the facets of the Barytes are very sharp
in the mould, and indicate some rare ones that appear to
have been extremely smooth with bright and polished sur-
faces. Whether the Ochre, or other pulverulent matter
which is about the specimen, helped it to separate, I dare
not say; but I scarcely think that would have been suffi-
-cient of itself.

WA) Last ba
a fr)
ah 4

eee)

erly Lnilin.

f/
SH

37

TAB. CCCX XIII.
CALX _ carbonata.

Coralloid Limestone.

Div. 2. Imitative.

Sreepie-AsuTon, Calne in Wiltshire, and the neighbour-
hood, afford vast quantities of Coral Rock, most of which
has the common appellation of Coral Paste. It is frequently
semi-transparent with a waxy appearance, and the Corals
impregnated or cast in it often help the deception. In well-
chosen pieces it takes a fine polish, and often exhibits the
structure of the Corals and other things which it contains,
very beautifully, either like those found in Flint, ¢ad. 291,
or some other species, of which there seems to be a great
number. The present specimens somewhat resemble, and
are even more instructive than those from St. Peter's
mountain near Mestricht, which seem to have been con-
- tained in a very similar stratum. It appears that the nature
of these Coralloid Fossils has not been determined—see
Parkinson’s Organic Remains, Pl. xu.1.2. This speci-
men shows that they ought to be considered as casts with
regard to the Coral, which is evinced by the sted/@ on the
case of the Mytilus, which, for the sake of distinction, I shall
call M. tunicatus. On uncovering some of these I found
specimens sufficiently perfect to develop the truth, they
having been often considered as Pholades, and lately as
Alcyonia; but we must not allow of too much latitude for
hypothesis,

The upper corner figure is one of the cased Myiili co-
vered with remarkably formed crystals of Carbonate. of

38

Lime—see the outlines near the bottom of the plate—often
having the facets, as on the outdine below, mostly convex
and rounding,

ping the case like the left hand figure. This specimen bas,

and sometimes bending round or enwrap-

in common with others, the granule that betray the Bath
Limestone, tal. 8, and the partly Stalactitical Lime, as
in tab. 1, of a very white colour, and paper-like form—
see the middle figure of the second row from ihe bottom of
the plate—or with the fibrille*, some tolerably distinct,
and others very minute and very beautiful; these often re-
semble worms, and we occasionally find the remains of
true Serpule, or a kind of worm-shell like those often
found on oysters.

The large upper figure evidently shows great variety of
easts ; the Madrepore often forms six cordate appearances
placed star-wise, with or without a column, and other
whimsical deceptive appearances. The Mytzlus has its
dwelling among these, its case is variously ornamented with
them, either as stars which are the ends of the Corals, or
as strie, which are the sides of them. Within one of the
coats the hinge end of the Muscle is very distinct. The
Muscles are occasionally larger. The specimen below shows
a number of smaller ones in a smaller Coral. Both these
specimens came from Calne. The lower bottom figure was
taken out of a Steeple-Ashton turbinated Coral, the shell
having the stri@ and appearance of a fresh bivalve. The
next figure is from one taken out of the small specimen,
magnified; and the left hand one is a cast of Carbonate of
Lime, such as is found within the shells, which determine
them to be Mytili. This is covered with an Ochre, as are
most of the specimens of Corals from Steeple-Ashton.

* These, Mr. Parkinson thinks, argue against the stellated appearances
being the remains of Coral casts; they are partly Stalactitical, produced since
the formation of the Coral, and partly the casts of minute worm-holes.

S24

Aug. 11699Publishia by J Sowerby. Loniion.

3g

TAB. CCCXXIV.
Chlorite Marle.

Wuen at Sidmouth I found on the shore, nearly under the
marley rocks, a Limestone of some tons in weight, replete
with shelly remains like this specimen, which is part of
an English Boulder. This was in Mr. Day’s collection,
and he used to admire it for its singularity. It is composed
of Marle and Chlorite with the Carbonate of Lime shells ;
and the chain-shot appearance of the sections of the shells
is always presented, let the stone be broken or cut on which
side it may ; which, in most other stones from Devonshire —
containing shells of a similar structure, seldom happens ;
for these generally break parallel with the sides of the
shells showing their volution. The Marley Chlorite includ-
ing the shells is rather the less compact, and takes a bad
polish, as in the attempt it becomes rather browner. Upon
being fresh broken, it presents a greenish tinge, which is,
I presume, owing to the Chlorite.

41

TAB. CCCXXV.
Cotham Marble.

Syn. Argillo-Calcite. Kirw.

Coruam, near Bristol, affords this remarkably figured
Marle, which, according to the Bristol Guide, you may
often imagine is a fine drawing. It is a curious formation
of Marle and Clay, chiefly stained by Iron, and perhaps
occasionally by Manganese, forming, by settling in
moisture under peculiar circumstances, the top undula-
tions, sometimes representing clouds in a sky, while the
bottom imitates earth and water as in landscapes. The
fanciful figure to themselves in this something like a boat
and men in one part, and hedge-rows in another, with trees
in full foliage. The appearance of the different parts seems
in a great measure to point out the different substances.
The whiter part is softer, and has most Lime; the bluer or
grayer have a dilute mixture of the black Oxide of Iron; the
browner part being still harder in consequence of the state
of the Oxide of Iron, and the quantity of Clay or Alumine ;
for it must be remembered that Clay often has much Silex
mixed with it. The deposition indicates the mass to have
been more fluid in some parts than in others ; and perhaps
some conjecture might be formed as to the trees having
distilled in drops from the upper waved surface; but at
present we must rest with the theory, the practice of which
may lead to useful ad certain truths. This substance is
found in broad slabs, and is cut transversely from the
thickness of an inch to a foot or more. It is sometimes
adinired for ornamental chimney pieces, and the masons in
the neighbourhood have used a geat deal of it for such pur-
poses.

Sg 1160, niblidhd by fe hiner by Lindon.

to

43

TAB. CCCXXVI.

COBALTUM._ arseniatum.
Arseniate of Cobalt.

Class 3. Metals. Order 2. Oxygenized Compounds.
Gen. 7. Cobalt. Spec. 1, Arseniate.

Gen. Cuar. Cobalt united to Oxygen.
Spec. CHar. Oxide of Cobalt united to Arsenic
Acid.

Fyowers of Cobalt; commonly so called, are found at
Bruton quarry near Edinburgh, and at Alva mine in Stir-
lingshire. The beautiful soft and tufted spicule of the
upper specimen were, when fresh gathered, of a most bril-
liant satiny appearance, reflecting a fine light or dark rose
colour. The little tufts radiate from a centre nearly ina
globular form. They are extremely tender to the touch,
and lose their brilliancy in a lighter powder. Sometimes
the spicule have a flattish reflecting side or surface, and
spread in broader masses, somewhat resembling crimson
velvet or plush: they are occasionally nearly white. The
middle left hand figure represents the little spicule spread-
ing in tufts. The right hand ones are of the same mag-
nified. The lower figures have the spicule somewhat la-
minated; the left hand one being magnified. Cobalt Flowers
have lately been imported, and are very valuable. They
were first discovered in the quarries near Edinburgh by
Dr. Smith, P.L.S., when a student at Edinburgh, in 1781.

OBEN AUD
BRS) fe
A NO

327, *

A5
TAB COCX X VIL

ARGENT U M nativum.
Crystallized Native Silver.

Class 3. Metals. Order 1.
Gen. 14, Silver. Spec. 1. Native.

Div. 1. Crystallized,

Syn. Argent natif octaédre. Haty, 3. 385.

Tus specimen of Crystallized Native Silver, accompanied
by Flowers of Cobalt, was sent me from Alva minein Stirling-
shire by my kind friend formerly mentioned in this work by
the name of G. Laing, Esq. It is a very useful specimen, as
exhibiting a very elegant arrangement of the primitive nie
clei, if I may so call these minute octaédrons, to see which
the help of a magnifying glass is required ; and we may in-
dulge a conjecture that the Silver settled from its solvent,
whatever that was, at the time the mass was soft, which,
when hard, retained it in this state for our instruction.—
Thus we see the nuclet arranging themselves from loose or
distant order, as if preparing to form the close and com-
pact order that is sometimes seen. There being small
octaédrons placed at right angles, and then others arranging
in the intermediate spaces, is admirable. We are here in-
formed, as it were, that an accumulation of octaédrons may

be so minute as nearly to fill the interstices, seeming to

46

exclude the necessity of the tetraédrons, which, I believe,
have not been found in Silver.

Thus we have a British specimen of what is reckoned the
primitive form of Silver. The matrix of the upper specimen
is chiefly Quartzose, with some grey Silver having the Na-
tive Silver in spots or blotches, and the Cobalt in a white
and husky powder. The lower specimen consists chiefly of
Limestone, with minute crystallized Silver among the grey
Silver which is represented larger. The rose-coloured and
whiter parts are Flowers of Cobalt, or pulverulent Arseniate
of Cobalt. .

fea
1h ¥
+
K ?
\ ts . ‘
i *. '
‘ A
‘ F é 4
aL -
~ , ‘
‘ sf
a ac
Fy .
o% ‘
‘
‘ i me
_ q

eae ee

AG

TAB. CCCXXVIIL.
Hornblend.

Syn. Common Hornblend. James. 1.357. Kirw. 1.
213,

Gemeiner Hornblende. Emmerl. 1. 322. 3. 267.

Hornstenp is common in some of our rocks in various
amorphous forms. In this specimen, where it occurs in
its close, very compact state, it is of a greenish black co-
lour; but as it seems to spread and become less compact, the
green hue grows more and more sensible. It issaidby many ~
authors in this latter state to form Greenstone with Quartz
and Feldspar, or Grunstein of the Germans; but other
substances may form Greenstones : hence the necessity of
noticing it. Chlorite may be often confounded with it
when the Hornblend is divided ; but Chlorite is never so
dark, hard, or compact as Hornblend, which can with
difficulty be scraped with a knife, and composes the darker
parts in this specimen. It takes a good polish as well as
the white parts, which are hard Feldspar. The green
mixture is rather granular and softer, containing Feldspar.
This Stone has several conspicuous particles of Sulphuret
of Iron, and of Magnetic Iron. It was part of a Boulder
from a gravel-pit near York, and may be called an Horn-
blend Porphyry with Pyrites and Iron.

Oct 11e0g pllish dl by Shower y Lindon.

AQ

TAB. CCCXXIX.

CARBO. bituminosus.
Staffordshire Coal,

Iw Coals we see an astonishing contrivance, not only to
preserve ancient and vast woods and forests to provide for
future contingencies, but, as it were, to the very produce
of each successive term of the former vegetable surface ;
thus acres ‘are piled upon acres and laid up in the grand
storehouse of Nature, that poring may be lost to all-fa-
youred Mankind! i

The present Coal is perhaps little else than the remains
of wood, and is comparatively but little altered in its con-
struction from situation. The more charcoal-like parts are
rather less distinct than in the Newcastle Coal, and the
bituminous part mixed more confusedly with it, and. it
upon the whole contains less foreign ingredients, as every
one may experience in the burning it. If slowly burned it
will produce ashes which exactly resemble burnt wood,
with very little chemical difference. The figure represents
the progress from the Coal at the bottom through the
cinder to the white ash. The watery parts go off in steam,
and the most volatile, the hydrogen and oleaceous parts
succeed ; then follow the more bituminous, leaving either
carbon or ash, according to the degree of heat and time of
exposure; or if burned very briskly and in a strong heat,
it might become a clinker. Thus I conceive that we have
a sort of analysis.

‘That Coals differ much under certain circumstances
there is little doubt ; this kind is apparently nearest re-

VOL, lV. F

50

lated to the Cannel Coal by the present analysis, only
instead of being somewhat slaty and very compact, it
has an external resemblance to Newcastle Coal, which,
however, always produces a more perfect cinder irregularly
formed, while this in the process divides into rhombic
shapes, splitting and curving into branch-like appearances
as a cinder, and becoming sometimes blunter and varie-
gated, passing totally into the shaley ash, outwardly re=
sembling wood ash, and like that very light, as it is
extremely pulverulent. I should consider this, nearly as
Mr. Mushet’s Derbyshire Cannel Coal, to contain

Volatile matter, geese tee sen «. -(- 447

Carbon... :.:.jauel dete mes pee 2S

Ashiesi 00/4 %.,.7 Seltyyes seme ni A

DOSS i <:; <8he liniaulines teieeanae VL

Great varieties of Coal may be found in the same bed,
consequently differing in analysis, some containing Sul-
phur, more or less Earthy Matter, Iron, &c.

fot 120g fubla thd by j? Fienty Li Whit.

51
TAB. CCCXXX.

CALX Fluor, var. arenacea.
Arenaceous Fluate of Lime.

Div. 2. Imitative.

Syn. Bab. p. 24s

Fivor is not only found crystallized in company with
Quartz, Sulphate of Barytes, Galena, &c., in aggregate
groups, but detached in very small cubic Crystals scattered
in the Lime rock—see the upper figure, where the Fluor is
seen in dark cubes scattered among brown Limestone.
Fluor is also found stratified in cubes smaller and smaller
until the eye cannot discern them, being in sand-like
grains, and finally pulverulent and undistinguishable from
their fineness, even passing dendritically among the Car-
bonate of Lime or Sulphate of Barytes. The noble-spirited
Dr. Jackson, who, will always sacrifice the best of his
collection for public use, was so good as to give me a beau-
tiful large specimen of this kind with Calamine and
Galena, the latter of which is often found in small de-
tached Crystals in the same rock with the Fluor.

The lower figure is granular and pulverulent Fluor, re-
peatedly stratified with Sulphate of Barytes, which is not
very common in an earthy form. Fluor is often of a fine
colour when the Crystals are transparent, their transpa-
reucy often giving great brilliancy to their colour. The
middle specimen is a good example of a tolerably fine purple
in the granular or dusty form, which form is seldom ad-
vantageous te colour.

The specimens are chiefly from the neighbourhood of
Castleton in Derbyshire: such are indeed found in other
parts, but not frequently.

BR,

Ye St vow: tsto0t

re

Hie AE braagills ocean Rat, vader tort ai

Ge Spann

HORT EIES Ct i coat
Boat AER

2

swiss) Ss we ‘st oe a

ied is ‘ is F x PERN) =
ANSI RR ANNE ss) So BSS int! wie. I
ei mel Oa ayes}

dap eee ssa iia oy

Ke ie sitchaeb “ isd
. 7 Beat oldie risinrgutine’l, at
ae tO ican galore ‘lial
\ bate sidan of seoreust 10 nigga lite ey 8 |

> ik Ye dart 3 ay wrth IPA ve Hite: ne eis! — ine uM

‘ - ,
al OE PES whe oy on ‘call wm regs ‘i <y

d'&
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eine aay Lgrete D el ik ) peyetlee
‘ ae -¥9 TH - ni : i | big
tori #i ' ote é. arp 9 ae a te tos ae Lire
ont & hy afte ef soit
(ya — <a if cfietepaciet HR BIR PS yt % nal i Wi

i ak}. canton. wate 0} voeemltrige Share - Bete aD

Vs - ‘ < TP : ; '
hg aren Die ont Vidierstel «te dldenans haog, gt Hoe
é 3 L ef ‘ ‘ , , mae

- hs colle i ori Ho:tha,.fi4 plenty
j 1 ‘ 3 $ be ur 2 : 7
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seed " am: ar, ‘ + ¢ 2 aha
; i } boorandigret at den gh uid IR LILES,

ov

7eato at fy iim bashes

331.

af Sf
4, weity Laitten ‘

fA by

58

TAB. CCCXXXI.
ARGILLA electrica.

White Tourmaline.

Tuts substance, which seems almost new to the whole mi-
neralogical world, not being spoken of by any author, was
sent me in 1804. ‘It was said to be found ina mine in
St. Justs in Cornwall. I speak of it as new, being really
a white Schorl or Tourmaline; for though Tourmaline is
said to occur of all colours included in mixtures of yellow,
red and blue, yet it is not mentioned as ever having been
found colourless or white until now ; therefore this is the
rarest known. It is transparent in the fragments, but is
so divided by cracks and flaws in general as to appear of an
opaque whiteness in parts. The form of the Crystals
agrees with that of Schorl. Their position, lying ex-
posed among Quartz Crystals, is rather new, as Tourmaline
mostly occurs imbedded in Quartz and Petuntse or Feld-
spar.

The late Hon. Charles Greville, who is much to be la-
mented from a loss I particularly sustain in the intimate
recourse he allowed me to his specimens, pointed out the
idea of my specimen being a white Schorl at the time I
first showed it to him; even that recollection adds value to
the specimen by putting me in mind of a valuable friend.
I never could procure a second specimen, or he would have
possessed it. I do not know that he ever procured any. I
believe Mr. Herbert, who kindly presented me with this,
has one also.

Among the small Crystals on this specimen is one that
most happily shows the primitive on its end almost de-

54

tached, as if it were done on purpose, nearly as figured in
the outline, which gives it the appearance of lying fitted
on the column; indeed the two acuie ends are partly trun-
cated by the narrower faces of the octagonal column. |

The right hand outline shows the faces of the pyramid
and column, which are very distinct.

The left hand figure represents the modifications of
some of the other small Crystals, with three oblique faces
not before observed by any author,—the thin outline and
shining part shows one of them: it was done thus, in order
that it might be known most distinctly.

Dane nay
pb AL Me Aut

352-

th G y Jat Ton e7by Linton

VE

TAB. CCCXXXTT.

Granite.

Class 2. Earths. Order 2. Aggregate.
Gen. Petuntse. Spee. Granite.

Syn. Roche Feldspathique. Hazy, 4. 430.

‘Tuts Granite is considered as of the primitive formation ; it
was once brought from Siberia as a great rarity, and cut for
seals, &c., at a handsome price, though not perhaps ex-
travagant, being brought so far: it however happens in this
instance, as in many others, that where curious minerals
are sought for abroad, the same are to be found at home.

Monymusk in Scotland affords many beautiful varieties.
One of the characters of Primitive Granites is the crystal-
lization of its component substances; the two of which
this is composed are, as it were, coeval in the act of crystal-
lizing, and each in part prevented the other, which gives it
the particular appearance in these varieties, said to re-
semble the letters of the Greek alphabet, though to me
they rather represent in form the Hebrew characters :—they
have, however, been termed Graphite and Siberian Greek
Stones most commonly.

The crystals of the Quartz occasionally terminate in such
a manner as to show their facets, and they often present
themselves remarkably flat, with a perfectly concordant
structure, and even new facets :-—-thus the shaded face in the.
upper left hand outline is at present new to this substance,
more particularly as being placed on the middle of one of

56

the pyramidal faces:—there is some indication of it in
some of the Crystals of tab. 319.

The position and angles of these Crystals caught in the
fracture of the Petuntse give the curious appearance. The
Petuntse has rather an amorphous appearance in general,
but is all crystallized; and when the large primitive sides
are reflected to the eye, they show its beautiful and peculiar
lustre. It sometimes shows the terminations. The Quartz
varies in colour from transparent to gray brown and nearly
black—the Feldspar, from white to reddish and brown.
Micais found in moderate-sized specimens. Two of the in-
gredients would constitute it a Granitel ; three, a Granitine
of Kirwan: but these distinctions are not really of conse-
guence ; and I am afraid the term Sienite is not much
better, unless perhaps as an original term used by Pliny.
It is understood chiefly to consist of Feldspar inclining to
red, and Hornblende, and sometimes are added Quartz and
Mica, as I and others have it from Egypt; myself by fa-
four of Mr. W. Morel, being detached from one of the
pillars at the entrance of the temple of Isis in the ancient
Canopus near the fort of Aboukir. Its structure is that of
Granite with the addition of Hornblende in a small propor-
tion,

0g full ished by far Somerby London.

BSS:

57

TAB, CCCXXXIFI.

Stenite.
Class 2. Earths. Order 2. Aggregate.
Gen, Petuntse. Spec, Sienite.

Turs, although very different in appearance from what is
to be expected in Sienite, agrees as to the ingredients,
especially as being composed chiefly of Feldspar and Horn-
blende ; the latter being more or Jess in partly formed black
Crystals. The Feldspar is grey with a blue iridescence,
which is better conceived than figured. The iridescent
faces of the Red Feldspar sometimes possess this lustre
most beautifully, and I have specimens which I picked up
in the road in my neighbourhood, which I suppose to be
more rare than the present, which I purchased at the late
museum at Yarmouth, as brought from near Aberdeen in
Scotland. This is, according to some, a Porphyritic Gra-
nite; the Feldspar being relieved by the dark ground gives
it a porphyritic appearance.

This is sometimes called Scotch Labradore Stone, on
account of the iridescence, which is of the same nature in
the grey Feldspar of Labradore, though they are much

more brilliant and yaried in their colours.

dtd sepsis

wets anf ae

“Oe DTU aA
Bre

Let est

oy oe

sy qhoehk ite boie

a Vy
¥

thashdt by J Somerty Lenin

59

TAB. CCCXXXIV.
Schiller Stone.

Syn. Schiller Spath. Lmmerl. 3. 340.
Spath chatoyant des Allemands. Hauy, 4. 395.
Schiller Stone. Jameson, 1. 428.

A reapy mentioned at tab. 221. This substance is not
much known, and although tolerably easily detected when
in Serpentine, is not otherwise much unlike some sorts of
Hornblende; it is, however, much softer, and is rather easily
scratched with a knife, giving a white streak somewhat
metallic in lustre, and having a plated appearance. In
the British specimens, either from Cornwall or Scotland,
the plated structure is more or less readily seen in numerous
brilliant specks, from the tenth of an inch to upwards of
half an inch in size: the larger plates have frequently a
broken or ragged appearance, with holes in them penetrated
by the duller Serpentine, or its flat surface forming round
about the rugged earth, which often accompanies the dark
brick-coloured Serpentine.

The plates seem very thin, and accumulated upon each
other ; and this is partly seen in some rhombic sides, re-
sembling some slaty structures: on the other sides it is
not at all discernible. The substance on the whole is of a
dull blueish green, or middle greenish grey—see my Elu-
cidation .of Colours, tab. 5 and 6, No. 47*, The plated

* It is usually called Olive green ; but olives differ very much. I feel con-
fident that a table for colours and reference will be most exact.

60

faces reflect yellowish and reddish illinitions, probably from
the position and colour of the matrix. Its peculiar glance
is pretty well represented when we see the whitish shining
appearance of the print. The substance itself is chiefly
recognizable by this glare. On Charcoal with a blowpipe
it melts into a black enamel, difficultly when compact, but
more easily when in a looser and rather decomposed state,
when it is generally of a reddish hue. It has often been taken
for Hornblende: it looks very like some Feldspar in its
peculiar lustre; and I have seen Carbonate of Lime some-
what resembling it, in the coarser crystallized masses of
rocks.

Mr. Hatchett is said to have first observed it in the Ser-
pentine of Cornwall; and I have received specimens from
my kind friend Philip Rashleigh, Esq.; and this month I
received a specimen gathered by Mr. Jackson in Montrose,
Scotland.

At e0y pulltshad ty fit Yonerby Lindin.

61

TAB. CCCXXXV.
The Alluvial Depositions forming Soils.

Class 2. Earths. Order 3. Mixed.

Tue surface of the Earth, alluvial or vegetating Debris, so
admirably contrived by the laws of Nature for our agricul-
tural use, have scarcely been attended to by Mineralogists,
and in general make so small a part in their works, that they
would seem to be of little consequence ; and the import-
ance of a more accurate knowledge, and the very use of
them in vegetation, has even been superseded by many chi-
merical ideas. Nature kindly allows, and even invites us,
to show industry and sagacity in many instances, but we
must be heedful not to mistake her contrivances. -

The top figure is arepresentation of a very fissile rock of a
nature scarcely noticed: it is a variety of clayey Shale, con- |
taining a small portion of Iron and Bitumen: it crackles in
the fire, and when red-hot produces a little flame. The
outside passes in colour from blackish to a lightish rusty
brown ; it splits and falls to pieces in the weather, forming
at its foot a soil very different from the original appearance
of the rock—see the representations under tt. I had it from
Bakewell in Derbyshire, where it is considered as excellent
for Firs, Elms, and Fruit Trees. The Bakewell Rotten
Stone, dab. 240, is a curiosity in its agricultural character ;
it is well known to produce white Clover spontaneously
the second year after its being formed into meadow. Oaks
do not thrive in it: it is a good manure for gravelly soils.

The right hand lower figure represents a part of a red
rock from Beaumares in North Wales. It has very much
the appearance of a baked tile. The fresh soil formed from
this is reckoned very fertile: it forms crumbling lumps—

see the left hand figure—chiefly composed of Silex, Clay,
and Oxide of Iron.

62

TAB, COCXXXVI,

Moulds.

Tue genius of our country, often so happily exerted in
agricultural pursuits, has yet much to do in regard to one
of the first sources of vegetation; I mean the Mineral
Kingdom or Department, which assists vegetation, the link
of life, and support of the Animal Kingdom. The example
of old ground not requiring manuring is not common.
I am glad here to show one in the upper figure, which re-
presents Mould from Wilson field near High Wycomb,
Bucks, which produces regularly fine crops of wheat with-
out manure, and had so done for eighteen years in June
1801, when Mr. Allen gave me the specimen. It may be
remarked, that among some hundred kinds which I have
examined, I have not seen one exactly resembling it, and
therefore I presume to hope that external characters may
be of more importance in this subject than has hitherto
been suspected. It is evidently mixed with Chalk in little
pieces. The Silex seems to be in very small grains held
together by common Clay and vegetable Mould.

The right hand figures are from Orcheston St. Mary, about
two miles from Salisbury, famous for producing extraor-
dinary crops of Long grass. Excluding the small bed of
loose pebbles, which is a common washed gravel found
beneath, I have figured the Mould as it is immediately
connected with the roots of the plants, an inch or two in
depth. It seems to be fine sand, held together by Clay
mixed with fine dirty Chalk and vegetable remains, some
parts full of roots, and others more detached and easily
separated. Its situation allows of much water occasionally,

3I9

( ot. LIB09 pibicsh A lyf imenby Linctn.

63

which of course fertilizes it; but it has still a different ap-
pearance from any other Earth I have met with. The de«
tached pieces adhere rather strongly, and are rather hard
to break ; a character which I have known brick-makers to
call water-bound. TI believe it to be a vegeto-carbonaceous
binding, if I may term it so.

The next left hand figure is a soil ffom Shrewsbury with
which I was favoured by Colonel Green. Its peculiar ap-
pearance caused it to be noticed. It is a very fine, but
looser Earth than either of the former; perhaps has less
common Clay, and it appears to show niore Chalk with —
Siliceous pebbles; and it connects its particles so as to
leave hollow interstices, although often in largish frag-
ments. It produces good wheat, barley, &c. The lower
right hand figure is of a fine Earth for Oaks from Lord Fitz-
william’s fine Oak-park about nine miles from Shefheld,
Yorkshire. It is a light ochraceous Loam, chiefly Clay
and fine Sand coloured by a lightish Oxide of Iron with
some vegetable Earth. It is remarkable for an astringent
bitter taste, resembling Bark. The largest Oaks in Great
Britain are found in this park. The left hand lower
figure represents a Mould brought from near Bridgenorth
in Shropshire by my friend Mr. Charles Stokes. It is re-
puted as very fertile for Barley and Wheat, and for retain-
ing moisture when most of the neighbouring lands are dry
and sterile. There is a remarkable gravel terrace near it.
The red appearance with a peculiar softness in the aspect
makes it noticeable. Jt 1s mostly Sand mixed with Clay
and Red Oxide of Tron, and does not seem to have much
Lime or Vegetable Matter among it.

The analyses of Vegetable Earths, &c., are well treated
of in many books, particularly Kirwan’s Essay on Ma-
nures, and H. Davy, Esq., for the Board of Agriculture.
it is, however, desirable to gain as much knowledge as
we can of a soil by figures and practice also; otherwise we

64

cannot compare one soil with another, or the part of a
soil analysed with the land from which it is taken.
Lapidaries guess pretty well of hard Stones by sight with

practice, so should those concerned in agriculture. Indeed
it would be very convenient if we could compare a written
analysis, for instance, soil taken from Sheffield Place,
remarkable for producing flourishing Oaks, analysed by
Davy, and found to consist of

Water. hess ST cr 18

Silexo ior ah am sagiie 54

IMME y/t.-aygegey +f 128

Carbonate of Lime . 3

@xidelot Jromcd 5. . Srsiers

Decomposing matter . 4

Loss0) jet He. 5.20 # hes 08

and the Oak soil figured from Yorkshire: we might con-
ceive the five parts of Oxide of Iron to give the colour;
the Silex grittiness; the Clay unctuosity ; the Lime-taking
a part from its unctuosity as well as the Sand ; the Vegetable
a soft matter distinguished from both by a rotten and car-
bonaceous appearance. According to experience, his Oak
land would to me differ in being a little lighter-coloured,
having a little more chalky whiteness, or having a little
more Lime than ours contains, and perhaps being of a
finer grain. This may be learned best by experience; ana-

lysis may prove it.

Zee wisi publushil by J Sewenty Louden.

65

TAB. CCCXXXVII.

STANNUM oxygenizatum.
Oxide of Tin (in veins in Schist or Killas).

Ss
Class 3. Metals. Order 1.
Gen, 5. Tin. Spec. 1.-Oxide.

Div. 3. Amorphous,

Syn. Tin veins in the Killas, or argillaceous Schist.
Kirw. 1. 237.

ee

Ir is very instructive to see the form of ‘the Tin veins and
their direction with regard to the formation of the Schist
or Slate, they being either straight, or curved in a remark-
able manner, and usually crossing the laminz of the Slate.

The upper specimen came from St. Agnes in Cornwall,
and consists of the coarser Killas*: the oblique position of
the veins in the larger specimen shows it to be from a
lower part of the primitive Slate formation than the under
Jigure, in which they are finer and more parallel, being of

a rather later formation.

* Killas is the Cornish term for the primitive Schist in which Tin is found.

VOL, Iy. G

66

TAB. CCCXXXVIII.

Tue upper figure came probably out of a large vein of
Tin, and is what the Cornish miners call Shoad Tin. It
occurs in the neighbourhood of the primitive formation
among alluvial deposits from it. It is much the same as
that in the veins, composed of more or less confused
masses of Crystals. These, and even the perfect Crystals,
are often found worn into pebbles in the streams, and are
termed Stream Tin, resembling common Flint Pebbles,
or Gravel Stones. They are of different colours, as here
figured, and may Best be known in the first instance by
their superior and extraordinary weight in the hand. They
are also called Grain Tin when in grains or very small
portions.

The streams are often conducted with much attention
over chasms and small valleys to the lower grounds, where
means are contrived, by washing, to collect large quan-
tities, separate from the mud and other matters, and equal
to that obtained by mining. There is moreover less trouble

in the separating and breaking for smelting.

IG

‘nei Lond ne.

YEA be

CTIA flu

De

Want

g hil by Jn Lenton
Lee 1 50g pullliatil ly 4F Sinwerby hin

67

TA, Bu CECX XXLX.

STANNUM sulphureum.
Sulphuret of Tin.

Class 3. Metals. Order 1. .
Gen. 5. Tin. Spec. 2. Sulphuret.
| Dw: 1. Amorphous.
Syn. Tin Pyrites. Kirw. 2. 200.
Sulphuret of Tin. Babington, Cat. 214.
Zinnkiess. Emmerl. 2. 418.
Etain sulphuré. Haiiy, 4,154. 9

Tus was, and still is, a rare substance, and is only yet
known as found in Cornwall ; first at St. Agnes in the time
of the celebrated Klaproth, in a vein about sixty feet below
the surface, and nine feet wide; and since some has been
found at Huel Scoria.

The upper specimen was brought from the former place,
and, according to Klaproth, was found in what is called
Growan by the Cornish miners, which is decomposed Feld-
spar of the Granite rocks:—see fab. 224. Rasp, who re-
sided in Cornwall at the time, gave it, because it contained
much Copper, the name of Bell Metal Ore. To Bell Metal
it bears some resemblance, and is brittle like that. In so
large a vein it must be supposed to vary a little, being
occasionally grayer or yellower, with more or less Copper.
Klaproth observes that Rasp’s name would be more just if
thére were a larger proportion of Copper to the Tin. The

G 2

68

varieties of course admit of some allowance, and each may
be right; but their specimens probably differed.
The lower figure is of aregular texture and smaller grain 5
it came from Huel Scoria, by favour of my kind friend
Mr. R. Phillips. There is among it something like Mis-
pickel, or Arsenical Iron, of a grayish white colour :—see
Descr. tab. 150. It has a bloom and dark tarnish on the
outside. I was lately favoured with a specimen by my
kind friend the Rev. W. Gregor, from Huel Rock in
St. Agnes’s parish, which is a mixed specimen, including
Sulphuret of Copper and Iron. It had some indications of
the Growan matrix about it.
Klaproth’s analysis seems perfectly to agree with this
substance, as under:
IEC ice RPS IS:
COPPER awe iejaceee cg Pol aS
"S)) (0) OUTy th Seam ie L<c
MOUS eave Tesh sae oS
Hart bys Sy Secs ace oly) sue 2

100

It is arranged by most authors as Sulphuret of Tin, al-
though this analysis gives more Copper than Tin; but the
Copper is generally thought to be merely mixed with the
Sulphuret of Tin: indeed its granular texture prevents a
complete separation from the Copper Pyrites that accom-
panies it.

ee 1 iy peullidpd. by iff Sonerty London

69

TAB. CCCXLE.

COBALTUM oxygenatum.
Oxide of Cobalt.

Class 3. Metals. Order 1.
Gen. 7. Cobalt. Spec. 1. Oxide.

Div. 1. Amorphous,

Syn. Black Cobalt Ore. Kirw. 2. 275.
Native Oxide of Cobalt. Bab. 232.
Schwarzer-erdkobolt. Kmmerl. 2. 438.
Cobalt oxydé noir, Hazy, 4. 214.

Ow the estate of Sir John Thomas Stanley, Bart., at Al-
derney Edge in Cheshire, was found this variety and mix-
ture of Cobalt. The substance being now so very scarce
and valuable, the knowledge of this variety is of the more
consequence, as it may lead to the finding this Mineral on
some unexpected occasions. The bloom of Cobalt having
the crimson cast, is apt to betray it, and I hope, for the
owner’s sake, this may become more profitable than hitherto,
and lead to the acquisition of the more perfect substance.
This 1s so mixed with Sand, Oxide of Copper, Manganese,
&c., that it is of but little value as an Ore of Cobalt.

igs

stdnuh Is bias

tts viREYIO soe o o1nt9a ne
. = acs |

ae

ra m4 Cuan
_ - ee A ad
Lh acre r MM .39qg ce 10 °ODT AY
&

eee 2. eo » aac’
tovorO a a8 Ss

os

GAL

erly Lending

WL

“fe

df,

Lee Leap ft Mudie

71

TAB. CCCXLI.

PLUMBUM_ € sulphatum.
Sulphate of Lead.

Div. 1. Crystallized.
————EES__

"Tuese peculiar green Lead Ores have created some con-
fusion among Mineralogists, from their having been con-
sidered by several as Molybdates of Lead*, which, I be-
lieve, we have not yet found in this country. I was fa-
voured with the present specimen from Wanlock-head by
G. Laing, Esq., who has so often kindly given me occasion
to mention him in the course of this work.

The Crystal is a long rectangular prism placed upon one
of its sides. Two of its faces, the upper and lower, are
primitives ; the larger two terminal faces are also primitives,
being the sides of a rhomboidal prism; the middle of the
three smaller faces is on the acute solid angle, the other
two are on the succeeding, or the thus newly made solid
angles. We find this to be the same primitive as fab. 153,
which upon further examination proves to be also a Sulphate.
Tts insolubility in hot Nitric Acid diluted, confirms its
being a Sulphate, besides other trials, by some of which
we are led to suspect a small portion of Muriatic Acid ; but
we had too smail a morsel to try it perfectly t.

The green hue of the present specimen may depend upon
Oxide of Iron, or some foreign ingredient.

* Found in Carinthia.
t It would be very desirable that Mr. Gregor, Dr. Wollaston, or some such
person, in whom we may place confidence, would examine these substances.

ic
7 ore ed ‘st

toa sun pea

ae ra ae %

odinody
sto 301. sins Dime ato “i Bi 29%
bile abet vier) eadd oft Ww « gitibs yyotie oct a6 sia ;
SBOE Ans a ovinicibm oe — ad on ait bait OVE. olga)
ae yee Jenliege tadist fiogu sina’ ie

“se
i ont
i sol

leate, On DB

a, Bi ;

Baa

7 yh. fi)
LOC LLEUO Vite Lyf “Hower ty London.

(3

TAB. CCCXHLIL.

PLUMBUM™M. earbonatum.
Carbonate of Lead.

Div. 1. Crystallized ; in hexaédral lamine.
ns

Carzonate of Lead of this form and colour has for
many years been considered as a Molybdate. Its readily
effervescing in dilute Nitric Acid will, however, betray it.
The modifications of the present specimen are remarkably
striking, and are evidently to be traced from, or to, the
plated forms of tabs. 89, 90, andgl. The Crystals have a
light glare, and somewhat pearly lustre, and are in colour
from nearly white to greenish yellow; scattered in irregular
fissile hexangular plates, or more compact :—see the middle
jigure, which contains plates nearly like the lower left hand
outline, or piled up as that on the right hand.

These specimens are very rare, and occur only now and
then in the Wanlock-head mines near Glasgow. I have
one from Mr. Day’s collection, some years old; and some
by means of other friends. I do not know that they are
found elsewhere, or are at all described as green, or ap-
proaching thereto. They are said to be snow-white, grayish

and yellowish-white, cream-yellow, and clove-brown.

MIS - ula salt
felimibig o} aindw so evo
zoinl relay gusxod sl
EES is

pe qu | bali 10 oailino. |
g bien iooqa saad tT

pales W ide isi wd

ee <M mort oa

} bipe ous od I gee aid

MTBIIO Dulilwns

. va
’

vik
we "
ie

Va
thakd by fecerbyLuudon

49

TAB. CCCXLITII.

VISMUTUM nativum.
Native Bismuth.

Class 3. Metals. Order 1.
Gen. 13. Bismuth. Spec. 1. Native.

Div. 1. Crystallized.

Syn. Vismuthum nativum. V/Valler, 2. 205.
Gediegen wismuth. Emmerl. 2. 434.
Native Bismuth. <Kirw. 2. 264.
Bismuth natif. Hauy, 4. 184.
Vismutum. Linn. ed. 13. p. 128.

Tus is a rare substance as British, It came from Corn-
wall, and was among the specimens I had the good fortune
to procure of the late truly ingenious Mr. Day. It appears
in the centre of Amorphous Brown. Quartz. It has some
admixture of gray or dark Sulphuret and other substances,
perhaps Cobalt, with Oxide of Iron, &c. At Johann-
Georgenstadt and Sneeburg in Germany, it is sometimes
found crystallized in four-sided tables, in somewhat cu-
bical or truncated tetraédrons. Its primitive form is an
octaédron. The colour of the present varies from whitish
to tarnished yellow, reddish or purple; metallic fracture
more or less perfectly foliated, folia parallel to the planes
of a regular octaédron. The peculiarly beautiful crystal-
lization of this substance obtained by melting it in a proper
degree of heat, and then suffering it to cool, attracts at+

76

tention :—see the lower figure. The square or right-angled
volute might afford an excellent natural lesson or model for
a square column, pilaster, or frieze, in the hands of a
good architect. I conceive the original and best forms of

the ancients were derived more from natural subjects than
is generally thought.

iy Lae i a
a
‘A i}

WiigktlA eo
radial

ares

Dees 1e0g plulishd, Ly fe i twenty Luin ;

17

WA BO CECKALITVS
VISMUT U M_ carbonatum.

Class 3. Metals. Order 2. Oxygenized compounds.
Gen. 13. Bismuth. Spec. 1. Carbonate.

Div. 1. Amorphous.
eee

Tuts common earthy-looking substance, being chiefly
Carbonate of Bismuth, with a little Oxide of Iron, and a
very little stony substance, came to me by favour of the
Rev. W. Gregor, from St. Agnes, Cornwall. That gentle-
man, often usefully employed for his amusement in ana-
lysing minerals, is an honour to his country. We think
it of much consequence to figure such a substance as the
present; for, by remembering the figure or the substance,
we shall not too hastily pass over things which at first have
common appearances; but examine them with attention,
which will habituate the judgement to the easy discrimina-
tion ef obscure characters, and teach us to suspect what is
not quite usual, and therefore to examine it, if necessary,
by means of chemical agents.

Nature, in this mineral, seems to point out something
of the soapy appearance of Steatite:—see tab. 2225; but
it 1s more earthy, or rather harsher to the touch, though
the Oxide of Iron in some parts disguises it. The
weight in the hand seems greater than that of Steatite. As
Oxide of Bismuth has been found a most beautiful and
pleasant pigment for high-finishing water-coloured draw-
ings, and as the present specimen does not apparently
change colour, as that does, on exposure to light, I was

78
led to think it might afford a lasting pigment, and instead
of spoiling many a highly finished drawing, and operating
to disgrace the artist, Bismuth might be brought to re-
cover its own fame in the form of a Carbonate, and be a
lasting memorial of the spirit of the artist’s touch; but
upon trial I have not found the artificial Carbonate at
all equal in lustre to the Oxide.

GE.

Fob wiper shed by ff Sowerby Loin.

ro

TAB... CCCXLYV.

CALX ecarbonata: var. fibrosa:
Fibrous Carbonate of Lume.

Div. 2 Imitative.

‘Tuts substance has been long known; but, I believe, hag
not been noticed in any publication, if we except Dr. Kidd’s
Outlines of Mineralogy, I have a piece in my possession
which is reported to have belonged to _Da Costa, who was
said to be at a loss what to call it. I have also receiyed it
from different friends at various periods; which shows it to
be sufficiently remarkable to attract notice, and that it
would appear a desideratum if passed over in this Work.
It was probably first noticed at Bath, or in the quarries in
that neighbourhood; but is also found in most Limestone
quarries, varying much, accordingly as the stratum in which
it is found is more or less compact. I gathered the upper
specimen at Shotover Hill, where it is not uncommon?
but these were rather remarkable, as the fibres were mostly
so very loose as to resemble in texture some rotten wood,
which has lost the transverse fibres, and become petrified.
It separates into extremely fine filaments, which, after se-
parating, break so nearly, if not quite, transversely, as not
to show in the least the rhomboidal fracture (a character
peculiar to it and the Satin Spar). The middle figure shows
the varieties of its colour, from nearly white to the
usual brown; and was sent from near Bath. The
lower figure is taken from a specimen found at Mit-
ford, with which I was favoured by Thomas Meade, Esq. *

* J beg to correct a mistake in this gentleman’s name ;—it should always
be read as above, not Charles, and should have the terminal e.

VOL. ly. HN

82

It is remarkable for the bending of its filaments, and not
less so for the holes apparently formed by the Mytilus tu-
nicatus, (which IJ find abounds in variety of petrified Corals,
&c., found between Oxford and Bristol,—see tab. 323.)
There are also cases of Serpule about it. This proves that
the structure of the substance preceded that of the Mytilus,
and that it may have been coeval with the Corals, or even
of earlier formation. It is sometimes dull and opaque,
sometimes almost transparent, and nearly as shining as
Satin Spar*.

* IT must here remind my readers, that the habitat J have given for Satin-
Spar, tab. 5, p. 11, is correct; for some other authors have, by mistake, and
by copying from each other, named Derbyshire for its habitat, and this
seems to have originated with Jameson, who probably purchased some speci-
mens there, and where, not long since, has been found striated Gypsum or
Sulphate of Lime, so compact as much to resemble the Satin-Spar, and like
it has been cut for ear-rings, necklaces, &c. The former may be readily dt

stinguished from the latter by being easily scratched by the fingér-nails

Fh set fusktioled ly fli wtigbusston.

340

yet

85

TAB. CCCXLVI.
CALX _ carbonata.

Incrusting Carbonate of Lime. Osteocolla.

Div. 2. Imitative,

Syn. Osteocolla. Enc. Brit.
Chaux carbonatée incrustante. Hawy, 2. 172.

Osrzocotza being mentioned in most modern books, it
may naturally be inquired for in mine: and as I should hope
not to be wanting where there may be information given, I
herewith exhibit a figure of this substance, which is more
than ordinarily instructive, although only a variety of Sta-
lagmite. The present specimen was found near Shotover
Hill, and shows the curious mode of its accumulation,
especially as the substance of the branches is yet distinct.
It is called Osteocolla from being supposed to have a power
of uniting broken bones. It may vary with the nature of
the current that deposits it. This specimen has a peculiarly
soft and chalky, somewhat woolly, appearance. It is
nearly of the same nature as the deposit in a tea-kettle;
but that is harder, and may give an idea that it depended
on the water being heated. We find these depositions to
be generally about this hardness, or perhaps a little harder
and rather more compact. Westminster Bridge has a setuling
of the Lime frem the water on some parts of its sides of
acurious undulating figure; and moss with many other
subjects, such as birds-nests with the eggs, are covered in a
similar manner at Matlock.and Knaresborough, first settling
H 2

84

on the outside, and then accumulating as the substance
sometimes rots. - This is especially the case in Moss, when
it seems to have taken the entire figure of it. I add a spe-
cimen of the Moss ; but there are many varieties, some
even showing the species by the cast over it. Sometimes
the splashing of the water falling from a height heaps the
small grains on each other, and forms natural grottos. The
specimen figured below, having been deposited in the place
of a nut kernel, is truly beautiful. I was favoured with it
from Knaresborough by the Rey. W. Danby, accompanied
by reflections upon it, such as the contrivances of Nature
generally excite in a truly enlightened mind. Lady Wilson
has lately brought me some granula of Carbonate of Lime
deposited in water used at Charlton House, which are very
small, resembling common sand, and which help to show
that Ketton Stone is merely a deposition of the same kind.
Is it the disturbing of the water, or any particular motion,
that might cause the Lime to form granules? We have
great variety from this to the Botryoidal stones found in
Rutlandshire of a large size :—see tab. 284.

ty Lnulin

Hite

afublaled ty JD

wéh

Fete

TAB. CCCXLVII.

CALX carbonata.

Calcareous Schist.

Dw. 3. Amorphous,

ey RS ee ae ee
Tue term Slate is applied to very different Stones; but it
is more generally understood as belonging to the blue or
gray Slate, commonly so called when it is even a term for
colour, as Slate-colour; but this term does not lead to
accuracy, as Slate is found to vary in this respect. Colour
formerly helped to distinguish the species for common use3
but now many varieties, both in colour and texture, are
used! While Slates are common in some counties, in
others the people are strangers to them; and luckily find
Limestone so fissile as to serve for rocfing their houses ;
and this, being schistose or slaty, has obtained the appella-
tion of Slate.

The lower figure came from Stonesfield, Oxfordshire,
and has often in its fissile divisions shells, sharks’ teeth,
and other things of this nature. These Stones often have
fishes’ teeth in them, perhaps most remarkable at Verona
in Italy. When Stones for building are chosen from these
quarries, it becomes necessary to place them nearly as they
were in their native places, else by exposure they split per-
pendicularly, and fall from their places in flakes; which
may occasionally be seen in Limestone buildings.

The small upper specimen was found about 2 or 3 feet
from the surface in Sussex, and furnishes strong argument
for its yery recent formation. Little petrified shells, re-

86

sembling the minute stagnant pool muscle or bivalve, if
not one of the same species as now exists, cover it in every
division very abundantly ; and like other fissile Stones, the
bivalves show the convex on one side and the concave on
the other. I am obliged to my friends Messrs Borrer and
Weeks for the specimens in my cabinet. The next specimen
is from Stonesfield, a quarry famous for a great variety of
animal exuviz, especially of the genus Cornu ammonis.
This has an alligator’s tooth finely preserved. If we may
be allowed to judge from the teeth, there have been many
species of alligators enveloped in the catastrophe that made
such wonderful havock. The other two pieces, the upper
of which is without any appearance of petrifaction, are a
sort which is often divided by very silvery-looking Mica
covering the fissile surfaces, and mostly accompanying the
more sandy sort:—we find by Lady Wilson that it ap-
proaches even to a Jasper. The lower specimen has casts
of different bivalves, and has a hole in the top, which shows
in a small degree the manner of manufacturing them for
Slates. Several of the above specimens contain a consi-
derable portion of Sand. All Limestone quarries have a
more fissile Stone near the top: those of Portland, Purbeck,
and Bath are generally shelly, and sometimes merely a
congeries of compressed shells almost as thin as paper,

Sap, winjtlisbal ly fe Tverby Lyilape

——

87

TAB. CCCNLVIT.
SILEX talcum.

Massive Talc, Potstone, or Lapis-ollaris.

Div. 1. Crystallized.

Syn. Potstone. Kirw.1. 155.
Lapis-ollaris. /¥aller. Bab. Min. 39.
Talc ollaire. Hauy, 3. 257.
Topfstein. mmerl. 3. 282.

Aruoveu this is not a rare substance in countries where
Serpentine Rocks occur, it is nevertheless often too un-
equal in its nature to answer the purpose of turning into
pots. In Scotland it is abundant ; and the Duke of Argyle’s
house at Inverary is said to be built of it; yet it is but little
known. I have seen sets of tea equipage, and I have a
tankard made of it from abroad ; and in Saxony it seems that
hundreds of people are employed in manufacturing it. The
usual kind abounds with Talc, and is of an even and close
texture ; but that which is used varies much, and more or
less approaches Talcose Schist and Serpentine. Some of
the cups which I have from Italy seem to be a Talcose
Schist, with Garnets of such an equal state of hardness,
that the whole turned equally well.

The upper figure is a representation of a specimen from
Breadalbane of the common texture; but the fibres are
rather more than usually varied in their direction, so as to
make it nearly free to cut or turn to any form.

The lower figure is a more Schistose variety, from the

38

same place, commonly called Schistose Potstone. The
different kind of Potstones vary much in colour.

I have figured this substance rather as 4 mineral than as
a specimen of such as is turned in the lathe, although it
would answer the purpose pretty well in a certain pro-
portion. Itsstellated formation is rather rare; I have not,
however, represented that variety : but, from what has been
said, it may be readily understood that there may be nu-
merous varieties; and those of the most equal texture
throughout are to be preferred. They are generally some-
what porous, and sometimes do not hold water better than
the vases, &c., made in Derbyshire and cther Fluor countries,

The inhabitants of New Caledonia occasionally use a
sort of Potstone Steatite to assist them in the place of food
when it is scarce.

T wonder that there are no such Potstone manufactories
in Great Britain as those in Saxony; for I think there 1s
but little doubt of procuring the Stone as likely to answer
this purpose as the foreign sort. Perhaps, however, there
would not be a sale for them.

I49.

Fe

89

TAB. CCCXLIX,

ZINCUM sulphatum.
Sulphate of Zinc.

Class 3. Metals. Order 2. Oxygenized Compounds,
Gen. 4. Zinc. Spec. 2. Sulphate.

Div. 1. Crystallized.

Spec. CHar. Oxide of Zinc combined with Sul-
phuric Acid.
Syn. Vitriol of Zinc. Kirw. 2. 23.
Zinc sulphaté, HHauy, 4. 180.

Surpuate oF Zinc is found at, Holywell in Flintshire ;
and the specimens which I have were brought from thence.
It is formed on a red earthy Oxide of Iron, and is chiefly
distinguished from the Sulphate of Iron, or Copper, by its
whiteness, being commonly called White Vitriol and even
White Copperas. Ihave not seen it crystallized in its native
state. It is slightly laminous in its fracture, and is formed
rather irregularly in holes or foramina. It is soluble in
twice its weight of cold water, and has a strong stypti¢
taste, When pure it consists of

Oxide of Zine: 43) <1). 40°

Wistenic ea eee. SOrS

Sulphurie Acid’... 2075

pcge

x

ISAT OE

akan

350.

= a
fet, 310. fuchtished by J “Sinerty Lion.
y

Ol

TAB. CCCL.

FERRUM_ sulphatum.
Sulphate of Iron.

Div. 2. Imitative.

Tue upper specimen is a remarkably fine Stalactite from
Cornwall, and has been in my possession many years
without having apparently undergone any alteration, which
is seldom the case. I have shown specimens in Plates 23
and 28 which have a very different appearance. It is
commonly called Green Martial Vitriol, is usually soluble
in twice its weight of cold water, and less than its weight
of boiling water. It is said to have a double refracting
power in proper and transparent Crystals. It is used for
making ink with oak-galls, and gives it a peculiar astrin-
gent tasie. It produces black with any vegetable, and is
a styptic. The specimen figured above has some signs of
the primitive rhomboidal angles about it.

The lower figure is taken from a North Wales specimen :
it is more apt to decompose, and shows the changes it un-
dergoes under these circumstances, as it becomes yellow or
brown, sometimes crumbling into a Sulphur yellow. The
primitive Crystal is somewhat apparent about this specimen ;
but the lowest figure is most perfect in that respect; such is
sometimes found in Cornwall and Derbyshire. Dr. Kidd
mentions finding it in the Shale that overhangs Odin mine
at Castleton in the latter county. Sulphate of Iron is often
of a fair green colour, (see Elucidation of Colours) lighter
or darker, by which it is known from Zinc, which is nearly

92

white, unless coloured a little with Iron or Copper. Sul-
phate of Copper is always much bluer, and approaches the
Sulphate of Tron, if adulterated by Iron, which often hap-
pens. Spec. Grav. of Sulphate of Iron 1°83.
Analysis according to Kirwan:

Oxide of Iron’ . . . . 28

WWALED gti yey gere cdo seis ee

Sulphuric Acid . . . . 26

mA

ces

‘
ii Via"
yy

Ne
Re
he

Ms
ey

i
‘i
r

sy
WY
nS

Fetowpere pub labia by J howerty Lovalest,

TAB. CCCLI.

CUPRUM - sulphatum.
Sulphate of Copper, or Blue Vitriol.

Class 3. Metals, Order 2. Oxygenized Compounds.
Gen. 12. Oxide of Copper. Spec. 3. Sulphate.

Div. 1. Crystallized.

Spec. Cuar. Oxide of Copper combined with Sul.
phuric Acid.
Syn. Vitriol of Copper. Kirw. 2. 22.
Cuivre sulphaté. Hazy, 3. 580.

Accorpine to my specimens, which I have had many
years, this is found in those rocks which are usual in North °
Wales, in which Cubic Pyrites so much abound, and is
occasionally adulterated by the Iron. It is most pure when
nearly deep blue with a greenish cast; but is sometimes
lighter coloured, as figured. It is less ‘soluble than Sul-
phate of Iron, requiring four times its weight of cold water,
and twice its weight of boiling water for solution; itis also
styptic to the taste. It may be artificially procured of a
yivid and rich blue; but always having a greenish cast.

The upper figure gives the most usual appearance of it
upon the rock. The specimen figured below was, when
first gathered, of the beautiful blue cast of the fresh
broken inner part; probably some Oxide of Iron is the
cause of the outward change of colour, which, however,
doest not penetrate far into it. The best Crystals are formed

O4

artificially. The primitive form is a parallellopiped with
oblique angles :—see the bottom outline. Spec. Grav. 2°19.
Analysis by Mr. Kirwan:
Oxide of Copper . . . 40
Sulphuric Acid % . 7,7 4) 31
Water oc) ces) on) auuiola e

oes

100

Although water is necessary to this substance, as well as
to the Sulphates of Iron and Zinc, and might be considered
in sufficient proportion to make them aqueous species; yet
we rather think the specific appellation best given from the
Sulphuric Acid, as most essential to their nature.

“

TAB. CCCLII.

STANNUM oxygenizatum.
Hematitic Oxide of Tin. Wood Tin.

Class 3. Metals. Order 1. Homogeneous,
Gen. 5. Tin. Spec. 1. Oxide.

Dw. 2. Imitative.

Syn. Fibrous Tin Stone, Wood Tin Ore. Kirw. 2.
198.
Etain oxydé concrétionné. Hazy, 4, 147.

Tue peculiar hzmatitic structure of this Ore of Tin, or
rather the radiated structure that often attends the Hematite
or Iron Ores, having a woody appearance, has given rise to
the name, which serves very well upon the whole, although
we do not think it very apt, considering its hardness and
specific gravity. In its usual state it may most readily be
distinguished from Iron by merely weighing it in the hand.

The upper specimen is magnificent as ta size, being very
rarely found half so large. It was lent me for this public
use by Edward Hawkins, Esq., who possesses a fine assort-
ment, and is inferior only to one in the Greville collection.

The right hand lower specimens are of the most usual size ;
the left hand one shows the concentrating radir with the
outer coat bubbled as it were, and according with the general
appearance of the upper specimen.

It is perhaps an extraordinary circumstance that this
substance 1s not known to be attached to any rock, and it

96

was once thought that only one or two specimens were to
be found in which it was attached. Mr. Day thought he
had one, which I now possess; but I find that its supposed
great value now only consists in its being that identical spe-
cimen ; for, upon examining it particularly, I find it has
only the characters belonging to Iron Hzematites, viz. that
of being soft enough to show the streak upon being
scratched, and which is red, whereas the Wood Tin should
not vary in the colour of the streak, if it can be scraped at
all; also of becoming strongly magnetic when heated by
the blow-pipe upon charcoal], whereas Wood Tin scarcely
becomes magnetic, but is reduced to pure Tin. Klaproth
observes that this Ore contains more Tin than any other
Ore of the same Metal. It is found in Cornwall at St. Denis,
St. Columb, Alternon, &c. Spec. Grav. 7°29.
Analysis by Klaproth :

Din) Aas sdk OO

Oxygen es. 21°50

S/F IP RCE er pC nO 705)

Oxide of Trop ox. 5: 9. i020

SEA.

An160 published ly J nearly Loudin

97

ne COC WILT,

Common Argillaceous Slate, or Schistus.

Class 2, Earths. Order 2. Aggregate.
Syn. Schistus. Linn. Syst. ed. 13. 3. 37.
Argillite. Kirw. 354.
Argile schisteuse. Hauy, 4. 446.
Clay Slate. Jameson’s Mineral. 1. 334.

"Tue Slate commonly known as of a slate-grey colour is
found in many places in Great Britain, from Penzance in
Cornwall, through Wales and Westmoreland to the Calton
Hill in Scotland, where there are primitive rocks. Between
the different beds of Slate which lie in that direction are
beds of Litfie- slate, as at Plymouth-Dock, where one side
is Slate and the other Limestone. Many parts of Scot-
land, and Wicklow in Ireland, abound with this substance,
and some afford much variety. Lord Penryn’s, at Nan-
francon near Bangor, is quarried in large quantities for
London ; the dark grey and lighter sorts are used for slating
houses, and the less fissile ones serve for posts, or turning
into candlesticks and fanciful ornaments. Coat buttons
have been made of Slate, which proved very durable, and
often suited well with a dark, or light brown, or gray, or
mottled coat.

The front fizure shows the durable Slate of Cornwall,
which is used in as thin and light plates as any. It hasa
close, glossy, and nearly even appearance, and consists
chiefly of Chlorite with an intimate mixture of Quartz,

VOL, 1V. I

98

upon which it depends for its durability, as it probably
does upon the different degrees of oxidization of the Tron
contained in it for the shades of colour. Killas and all the
schistose rocks in Cornwall are only different varieties of
this substance, depending upon the Talc, Quartz, &c., be-
ing somewhat varied in quantity and texture ; which varia-
tion may easily be supposed innumerable, but which may
without much practice be recognized, although the word
Killas seems to have caused some confusion.

The lowest figure is Slate from Ingleton*, in Yorkshire ;
and, like the Irish, Welsh, and Scotch Slates, often have
cubes of Pyrites in them.

The present specimen is one of that sort, and has a newly-
noticed substance on two sides of the Pyrites. We have
mentioned it to many friends, but can neither gain intelli-
gence about it, nor learn whether it is to be had in better
specimens. This is somewhat like Asbestus, the fibres
being at right angles with the Pyrites on two sides only.

The left hand is a specimen from Westmoreland.

* This place is famous for dendritical Pyrites on the Slate, forming as it

were golden trees (see right hand Jigure).

Nye. (esc peablished by fs SwedyLauhn

wed)

TAB, -CCELIV.

Ir is not always that the substance which contains the
same ingredients as Slate, has the schistose fracture, as ap-
pears by its being turned in a lathe on some occasions. It
is rather remarkable that the Snake-Stone from Ayrshire is
a variety of the same substance as Slate, but is not generally
recognized to be such, on account of its possessing the slaty
fracture when in large pieces only, not showing it when
broken small. It is imported as a valuable and truly useful
article in many branches of manufacture; as for smooth-
ing copper, marble, &c. For the latter it is formed into
the shape of mouldings, as in the upper figure. This sub-
stance is known in a great measure by its being so regularly
spotted, which, perhaps, has obtained it the appellation
of Snake-Stone, by which it is well known among work-
men. The light brown colour is analogous to the unspotted
part of a snake’s skin. I have gathered nearly the same in
Cornwall, and some varieties are to be found, with the dark
spots beautifully relieved by satiny Talc of a looser tex-
ture :—see the under figure. 1 have specimens nearly like
it, but more indurated, from Keswick. The black spots
seem to be Hornblend, Chlorite, or Manganese.

In the upper specimen the black is generally of an equal
hardness and texture with the rest, or it would not suit the
workmen. When a stone from any quarry is found to have
the proper qualities, it becomes of much consequence, and
is a valuable article of commerce.

t@

silos 9 ae tite

( en)
elt te! yiotaat a

cre iter oO hog te
Hiveite sce

rant rghy wid

4 |
pitt itl

; ROE a ae
An! sti fruublisted by f° Ses ty Lone Th

101

TAB. CCCLYV.

Siliceous Schistus, Hone-Stone, or Novaculite.

Syn. Novaculite. <Kirw. 1. 238.
Whet Slate. James. 1. 331. |
Argile schisteuse novaculaire. fauy, 4. 448.

Hore-Stone is generally considered as a foreign subs
stance, said to be imported from Turkey ; and has hereto-
fore been always mentioned by authors as such. I can only
say that we have a substance so nearly resembling it in
England, that it may very fairly be considered as the same ;
and therefore I esteem the Hone a product of our own
country. It is more or less an attendant upon Slate. Its
colour is grey, light greenish grey, buff, and nearly white ;
its fracture splintery. I have it from the Carnarvonshiré
hills, North Wales, (see the upper specimen) of a cream-co-
lour, like what is usually called Turkey Hone. Such is
much esteemed by the cutlers at Sheffield, and is sold in
proportion to its quality. A piece of about six inches in
length, fit for sharpening a razor, was thought so excellent
as to be worth a guinea. Many varieties of Hone-Stone
are found near Conistone, in Lancashire, and are sometimes”
so prettily marked with dendrites as to have gained the ap-'
pellation of Mocoa Stones*. The greenish Whetstone with

* Mocoa stones from Germany are perhaps coloured by Bitumen, but.
those from the East Indies by Manganese. In the first, the dendrites are apt
fo wear out, in the latter they are durable.

\
102

small dendrites, from thence, is figured behind, and the
upper middle figure is one with the larger dendrites ; this
nearly resembles the darker Turkey Hone, or, which is much
the same, the Carpenter’s Oil-stone, but is more stained
and blotched. It is, of course, sometimes found without
ihe dendrites ; but I figure it thus, to give one of its charac-
ters, and to exhibit a specimen of the sort of dendrites
which are supposed to be Manganese, and are sometimes
like stains upon the surface, as in the middle figure, and
sometimes run through the Stone in great variety, as in the
back figure. Chorley Forest, in Lancashire, produces
a variety of Hones, or stones fit for sharpening tools,
which are called Chorley Hones. Indeed, there are vast
varieties of stones used by the cutlers, according to the
coarseness or fineness of the grain; and their distinctions
are all so essential, that it becomes of much consequence
to know the sorts for different uses, and the trade in them
is of great importance both abroad and at home.

It is perhaps worthy of remark, that these stones may
be scraped with a knife, and give, generally, a light streak
like that of common Slate, although they will grind the
hard steel that will cut or scrape them. Schistose rocks
of many different compositions resemble wood. Perhaps,
from some of those usually called Turkey Hones resem-
bling wood, they have been thought to be petrified wood. I
am possessed of Schistose Rock from Devonshire, which
has been called Rotten-wood rock, from its resemblance to
rotten wood. I have, however, some petrified wood that
would nearly answer the purpose of a Hone, from Somer-
ssetshire, which shows the lateral fibre very distinctly, split-
ting with the usual longitudinal grain of the wood, and has
a slaty aspect. |

4

e
A
“
y
a

G56,

103

TAB. CCCLVI.

SILEX piceus.
Glassy Pitchstone.

Class 2. Earths, Order 1. Homogeneous.
Gen. 4. Silex. Spec. 7. Pitchstone.

Syn. Pitchstone. <Kazrw. 1. 292.
Pechstein. Emmerl. 1. 262.
Petrosilex résinite. Hauy, 4. 386.

"Turse Stones are so like Pitch in general, that no one -
could mistake them, except when they vary in colour and
have a glassy appearance, as is sometimes the case. The
fracture in some fine specimens is large, concentric, sharp,
and conchoidal, in others more splintery. We figure one
‘of the latter, which includes Petuntse, or Feldspar, and al-
so has more or less of a glassy appearance. This, taken
in the whole, would be called Pitchstone Porphyry. It
came from Arran in Scotland, and contains Alkali. Hence
it nearly approaches common glass.
Quartz is so extremely likely to vary in its appearance,
especially when chemically combined with coloarific or.
other matter, that it may be considered as liable to as many
varieties as any other known substance. Thus it varies
from Calcedony or Agate, to Cachalong and the various
Opals :—see tal, 111. and also to Jasper, wax-like Horn-
stone, Flint, and even Pitchstone, Under the term Pitch-
stone may be included those siliceous stones which are fu-
sible and resemble glass, as they can scarcely be separated
but by fancied differences (as the usual appearance of Pitch

104

may be called either glassy or pitchy). There are, however,
distinctions in some of them, which may be founded on
geological principles, as their being chiefly combined with
either Lime, Magnesia, or Alumine and Alkali, which often,
perhaps, depends upon the kind of roek they are formed
in: the colouring matter being either Bitumen, Manganese,
or Iron, in different states of oxygenization and quantity.

Pitch is of different textures, and has a fracture more or
less large or small, conchoida!, or glassy, and lighter or
darker in the splintery illinitions, depending on the degree
of heat to which it has been subjected. Pitchstone varies
as much ; therefore, the present specimen may be called a
Pitchstone having a glassy appearance, with a rather small
conchoidal and sharp splintery fracture. As it includes
Feldspar, which spots it in some parts, it may be called
Pitchstone Porphyry. Itis generally harder than glass, or
will scratch glass as Flint does. We are not sure that even
Bitumen enough may not be found hereafter, to mark its
analogy with Pitch very completely.

The present specimens were obtained from Arran, where
the substance seems to, be found in veins in a Porphyry
rock, and to pass into the more usual appearance of Pitch.
It has occasionally a basaltic aspect.

The visible and chemical characters of Obsidian agree so
closely with those of Pitchstone, that they must surely be
considered as the same species.

go

357

105

TAB. CCCLVII.

Steatitic Pitchstone.

T was favoured with the present specimen from a vale neat
Clowance Park, in Cornwall, by Phil. Rashleigh, Esq.
The outer white parts are said to be Tungstate of Lime,
a very rare substance in Great Britain: there are also
some Asbestus and Ruby Copper about it. One great cu-
riosity attendant upon these substances is, that they natu-
rally contain an Alkali, which formerly used only to be pro-
cured from vegetables : the great discovery of the basis of
Potash and Soda, made by Mr. Davy, has thrown a great
light on these and other substances, as to their changes and
appearances, which we need no longer esteem positively
volcanic ; since the powerful agency of motion, with the at-
traction of these bases for oxygen, may give an effect which
- we here see to be analogous to the power of a glass-house
furnace. These discoveries thus become of much more
consequence, as they lead towards the elucidation of what
we were before totally ignorant of.

The fracture is more or less conchoidal, like Pitch. It

is as hard as Quartz and nearly as brittle as Glass; and,

106

perhaps, stands next to Cement-like Quartz, tal. 219, but
we do not know that the latter has any Alkali in it.
Klaproth found Pitchstone to contain
NOX uence, tai wie Seni wham
Alumine .

Sheer tea hat ey
Lime . bie Neate San NL o
Oxidevof dromisc sa. | 4. I
Oxide of Manganese _. . 01
OMA i cuyet te) tedube atummms ao TOFS
Water oie ah eee ce iten GOO
Loss .

e e e e e e 0°15

100°00

ee

ft ster plated ly fs Dycty Landon,

107

TAB. CCCLVIII.

CUPRUM Sulphureum Arsenico-ferriferum.

Arsenico-ferriferous, or Grey Sulphuret. of
Copper. Fahl-ores

Class 3. Metals. © Order 1. Homogeneous,
Gen. 12. Copper. Spec. 7. Arsenico-ferriferous sulphuret.
Syn. Gray Copper Ore. Kirw. 2. 146.
Fahlerz. Emmerl. 2. 238.
Cuivre gris. Hauy, 3. 537.

Grey Copper has been found in several Mines in Corne
wall. I have a neat little specimen in Tetraedrons from
Tavistock, in Devonshire, by favour of John Taylor, Esq.

The present very neat specimen came from North Wales,
and has many characters in common with the vitreous Cop-
per Ores found in Cornwall: it is, however, more brittle,
and differs in its crystallization. This Ore varies in its con-
tents, the specimens from Cornwall having only Copper,
Iron, and Sulphur; while the foreign ones sometimes con-
tain Silver, Arsenic, and Antimony. Its neat and smooth
grey stecl-like appearance makes it tolerably distinct. It is
more shining than the usual vitreous Ore in the fracture,
_ which is mostly small, conchoidal, and bluntish.

The present specimen has but little variation in external
colour, and, though easily scraped with a knife, is rather
harder than the common vitreous Copper.

108

The right hand lower figure shows the regular tetrahedron,
or primitive crystal, and that on the left hand shows some
of its modifications, which are sometimes rather irregular.
A fragment of this specimen heated by the blowpipe was
found to be difficult of fusion: it gave out arsenical va-
pours, and was reduced to malleable Copper without showing
any signs of Lead. Spec. Grav. 4°4460—4°4560.

A specimen from Freyberg, according to Klaproth, was -
found to contain :

SOPPCL 7 y 3) 5 Pretest hen « GARE
Sulphargsm aoe ee. ATO"
ATSEMIG, ioc e ue Wi aumesta. Us
° 0°35
SON edie, nay +.) fh an
Byass.!) ON ON PN GO ep

SVR ais tn rs te ous

eee

100°0

7

This analysis corresponds with the effect the blowpipée
has upon the Welsh specimen.

350.

109 |

TAB. CCCLIX.

CUPRUM sulphureum.
Subsulphuret of Copper, or VitreousCopper Ore.

Class 3. Metals. Order 1: Homogeneous.
Gen. 12. Cuprum. Spec. 4. Subsulphuret.

Syn. Vitreous Copper Ore. Kirw. 2. 144.
Kupferglanz. Lmmerl. 2. 222.
Cuivre Sulfuré. Hauy, 3. $51.

‘Tuts is one of the richest Copper Ores, and is very abun-
dant in Cornwall. Its crystals usually partake of the hex--
aédral prism. Thus we have very short truncated hexaédral
pyramids placed upon very short six-sided columns, with
many varieties on the same specimen.

The present specimen at one end has these crystals mac-
kled, which I suspect has not been mentioned before: see
the right hand figure, which consists of two crystals like the
middle one joined together. Some of the crystals on the
specimen approach the cross, like the left hand figure. I
have a good specimen, with many nearly such, but did not
think it necessary to give the whole. The one here figured

came from Cooks-Kitchen, Cornwall.

wont “8 a8

eG wands wed et brea yao a9

ozadl oats to oalsting yllasen alaieyy,

lnibiiax 5; arson 3 node: wiey wend

Bhi x2 utiles haisa~xta Tete:
. ponnioay + ") eta aif} 0 0 sainsiy
“Ont elntey 2 saad gad bid o¢70 M80 iss pon bia

{

9928: ; yiied hiarrotte IGE. a2 Jatt oath +9 equa F Ty

“galt 9ifit ekgpevra. o'r Yo aeRiagie otto oe st

I seg, eh Oel- ot

3 dow bify suc tlona ylaaser yon E bie sures ga
bowryil todd otto ot t jsiodvr ait oviy OF) ;

ellewonrn catacapi ae

111

TAB. CCCLX.

‘Turis variety of vitreous Copper Ore is also found at Cooks-
Kitchen, in Cornwall, but is very rare. I have received it
among other favours from Mr. J. Taylor of Tavistock. It
is worthy of remark, that the crystals are of a large size
to what is usual, and the hexangular pyramids, which are
placed base to base, are more or less elongated : thus has
Nature sported with the crystallization, so as to prevent our
measuring with certainty the angle of incidence at their
mutual bases. Some of the crystals have the regular bevel-
lings of Haiiy, perhaps, not to be measured with certainty ;
and some of the crystals have many lateral faces, so as to
give roundness, thus also to elude measure. The fracture
is mostly irregularly glassy, or minutely conchoidal. This
Ore is easily scraped or scratched with a knife to powder,
but is not brittle. The eolour is iron-grey within, darker
on the outside: some specimens have the blue watch-
spring lustre and iridescence. Spec. Grav., according to
Kirwan, 4.129.
By analysis it is found to contain :
Wopper 5 247 8n5
POM ye. ees
Sulphur so 6 WOrs
Sihea sa) ol Oge
The matrix is a mixed sulphuretted Oxide of Copper and
Tron* with Quartz, through which there runs a vein of the
vitreous Copper Ore with the crystals.
* The black Copper Ore of Kirwan, 2.143. Kupfer Schwartze of Werner.
This may, perhaps, serve as a sufficient specimen for this work.
This dusty or earthy ore generally accompanies the sulphurets, or other
copper ores. It is yellowish, reddish, or brownish black. Scarcely soils, Is
rather heavy. Contains about half its weight of copper; but, from being ge-

nerally produced by the decomposition of the other ores of copper, it of course
varies much,

ae oa wet t.

aieihry

ae a — si ‘Ww

~fovsik
Valder ves 7 eign
o} as Oe

| wis toma off
“ip aes edt: dabiotign PE WRE YD |
ae (c ae grabwoq a stind 5 ttt Ba Cai eton te haar. iden oi -
a. aint itive yorg-neri zi ‘wolee, ofT bind eet tad
‘uot ae att, vad 2st prac senon 2 obisiuo odt ao
bar sugol gain

‘ ppc avevik
ee into a5 bas iti baba:

J
)
iH , ¥
Selle od
A '
ule .
ae

aoe te sihimts aie At 2 pte bo
ti Heke . iieow eid ant aecrigdas roeiviliye 6 ee
write 40 eB layla. ets eitngqoaon qiler ateya, thy pasty y ote
at slice ylootme- bell d inword 10 deibbir tein ;
oy quis, mart jad pwnygto Yo tdyiew i Mad swont -

assuming Bo agli bw aie nad aafs do: enemas

Kise

113

TAB. CCCLXI.

HYDROGEN Bitumen.

Inspissated Bitumen, or Mineral Tar.

Class 1. Combustibles. Order 1. Simple.
Gen. 1. Hydrogen. Spec, 2. Bitumen.

Syn. Mountain or Mineral Tar. Hatchetét in Linn.
Trans. 4. 131.

Tuts variety represents Tar so much as to be well entitled
to the appellation of Mineral Tar. Naphtha and Petroleum
lead equally to this and to the soft elastic Bitumens, branch-
ing off on one side to the elastic and on the other side to
the unelastic, of which this specimen is one. It is inflam-
mable, and in other respects, as to odour, &c., it is like
the others. Itis found, apparently in the greatest abundance,
in the neighbourhood of Dumbarton, whence the present
specimen: it is otherwise very rare. It is remarkable that
the Iron-stones (Septaria) are the chief deposit of it. The
present specimen is part of one, and I have a Coal Septa-
rium not much unlike tab. 61, upper figure, that has this
soft substance in it. I have also a specimen among Quartz
and Yellow Copper Ore from Carrharac in Cornwall, with
some in a more brittle state, so as to take the impression of
the finger nail, but partly breaking at the same time with a
bright pitchy fracture. I have some also in Copper Ore
from Lancashire that unites the two; it is accompanied with
dark Limestone.

VOL, 1Y. Ke

114

This substance is dark brown, bas rather a greasy ap-
pearance, scarcely sticks to the fingers, and looks nearly
like the dark or dirty coom of cart-wheels, and as it were
lies about the divisions of the Septarium, or in the holes of
the other specimens. Smell, when a little heated, as usual
to the Mineral Bitumens; by some thought agreeable,
though very different from Vegetable Tar.” Breaks easily
with a rugged fracture; burns with much smoke; is not
soluble in Spirits of Wine.

Mineral Tar and Pitch are found in various states in the
islands of Trinidad and Barbadoes*, but I do not know
that any elastic Bitumens are found there.

* See Mr. Hatchett’s admirable account in the Transactions of the Lin-
nean Society.

by ser
ey

115

TAB. CCCLXIL.

SIrilE NX quartzum arenaccum.

Siliceous Sand.

Class 2. Earths, Order 1. Homogeneous.
Gen. 4. Silex. Spec. 1, Quartz.

‘Tue Sandstone of Fontainbleau is well known to crystal-
lize in elegant groups of very neat rhombs, that represent
the inverse Carbonate of Lime, containing one third or
more of Carbonate of Lime, which appears to guide the for-
mation*. I have met with nothing like it as yet in Great
Britain. One of my sons, however, some six or eight
years since, brought me some flatted Cubes or right-angled
Crystals, which he found among sand said to come from
the neighbourhood of Ryegate. Some were partly ce-
mented by a little Carbonate of Lime, and others were so
loose that they could scarcely be handled without breaking.
As I know of nothing similar, I represent it here as a ra-
rity in Great Britain. IT also add a variety of Sand which
somewhat resembles the Roe of Fishes, or large-grained
Ketton-stone, or Pisolithus, It was brought me by Lady
Wilson, who found it at Charlton, and is likewise cemented
by some Carbonate of Lime. Something like it is also said
to be found at Fontainbleau.

The darker and irregular specimen is from Oxford, and

* Exotic Mineralogy, t.1. See Proposal on the cover.

K 2

116

was taken out of the Ochre Pit. I have a large mass nearly
of this description, found in the mixed Lime and Sand
Stratum under the Thames at Rotherhithe, of which I do
not know that any one else has preserved aspecimen. This
and others are more or less cemented by Lime and Oxide
of Iron. We have, therefore, three remarkable formations
in the Sandy Stratum, which may prove highly instructive.

ee ——— se ——— ~ or

At oy wé10 fullish ty Fe Serverby Lirake,

117

TAB. CCCLXIT.

ARGILLA Topazius.

Topaz.
Class 2. Earths, Order 1. Homogeneous,
Gen. 1. Argilla. Spec. 11. Topaz.

Syn. Occidental Topaz. Kirw. 1. 254.
lepag, 2 2mmenlnadlian 73:
Topaze. Hauy, 2. 504.
Borax, gemma nobilis Topazius. Linn.

Torazes have been found in the island of Ceylon, the
Brazils, Bohemia, Saxony, Cornwall, &c. In Lesser Asia
a rose-red variety was discovered by our good friend Mr.
Hawkins before mentioned in this work; and since that
they have been found in New Holland, and in Scotland,
The specimen figured is from Cairn-Gorum, and was lent
me by its kind possessor Thomas Allan, esq. It is the
more curious, as part of it is of a fine light blue colour*,
and part cinnamon-coloured, with a beautiful soft glowing
warmth ; and the disposition of the two colours seems al-
most to explain the nature of the crystallization. I thought
therefore it would be instructive to give a figure of the base
of the crystal, showing nearly the form the colours are dis-

* Topazes are of different colours, from deep wine yellow through reddish
yellows to greenish and rarely blueish ;—also colourless and transparent,

118

posed in. See the left hand lower figure. The right hana
geometrical figure shows the faces of the crystal, the top
and bottom being primitive, with which the fracture agrees.
This figure is about the size of a crystal, from the same
place, in the possession of R. C. Fergusson, esq. which has
the same colours as the other, though more dilute. This is
perhaps peculiar to the Scotch Topazes, as may be verified
hereafter ; for they may prove to be more common than is
now expected. The people that gather them, often call the
Cairn-Gorum Quartz by the name of Topaz (being a stamp
of value); and they are sold indiscriminately. This cry-
stal, which bears the marks of many a violent storm on its
worn edges, has been broken through the primitive base
transversely to the column, and is fractured in the lamine,
showing the order of the prismatic colours very well; and by
pressure these colours are spread wider, which shows that
there is a great degree of elasticity in the lamine.

The geometrical figure is to show more distinctly the faces
that-are in the principal figure, which is rather remarkable
for not having the faces so constantly opposite as they ge-
nerally are in Topazes. Between the large pentangular face
(mz of Haiiy) and the primitive apex, there is a parallel face,
not mentioned by Haiiy, and perhaps one opposite, but so
small that, as the crystal is rounded by attrition, we are
‘not sure it is there. At the lower corner is the triangular
face (c of Haiiy), on the nearest side, but I think not on the
opposite; but itis marked in the outline to show where it
would come. The two faces on each acute side of the
prism are primitive, on the top of which a want of increase
forms two faces (0, 0, of Haiiy).

The larger four sides of the prism are the faces (2 of
Haiiy). The figure within the outline shows the position
of the primitive faces and fracture. The obtuse angle of
the base is 124° 22’ according to Haiiy.

The value of Topazes depends much on their colour and

119

lustre. It is supposed to be the hardest substance known,
excepting Diamond and Corundum. Their hardness, frac-
ture, and brilliancy may have confounded them with Dia-
monds; and it is said that Saxon Topazes are heated to give
them a white transparency*, and are then actually sold for
Diamonds—it is even suspected by some that the reputed
Portuguese Diamond may be only a Topaz. Spec. Grav.
3°464—3°564.
The Saxon Topaz analysed by Vauquelin afforded him

Alnmina ia "4.9

Silreae ey eaves 420

Eluoric Acid) )..): 20

Loss GER Se or sae

The Brazilian gave
AAAI Ns ee penny
Silica, Vr Gea tee te ee S
Fluorne Acid”! 223) <" 17
Oxide of Iron’ i7; 244
Loss See mrnrC eae

* | believe the same is done with some Diamonds. It is very usual with the

dark Cairn-Gorem Crystals. See Descr. tab. 102.

anit, plaron sie psec how bron

| onic, ative: east: habapatsa:a gan ‘ened yonst .
ie “oyig od-beisad si poate aomdctaile bine, abet

iets wok bloz vifsilas.nadtcin bios ae eta oe
ber agar. ody. spats gutoa. yd hloot iinet nows Ai ©
ee 9992): eagle. vind sd a eel $
SN NAPE : aris hobios ail:
h
1 n
Se
Pa a
f 4 & hi Ry
Tg :

a . “ot cptnaced Tse iT abrorelt, dite sonfh pe puerto oN
. y +

eh | BOT ter, siete ae edie Gy

| oe » : ee Le deeds ria A = a Sas

y
Wii,

J

¥ } nae, ;
Janes eto pulled ly fl Jierty Lu

121

TAB. CCCLXIV.

STLEX granatum.
Garnet, or Pyrope.

Class 2. Earths, | Order 1. Homogeneous,
Gen. 4. Silex. Spec. 26. Garnet.

Syn. Pyrope. Le grenat granuliforme de Bohéme.
Hauy, 2. 555.
Edler granat. Lmmerl. 3. 246.

Mrxerarocists have made a division in Garnets, (if 1
may so express myself,) by considering Pyrope as a distinct
species, when its only distinguishing character is its being
found in irregular pebbles and not crystallized. Lapidaries
Jong since used to consider Scotch Garnets of a peculiarly
brilliant lustre as different, under the particular appellation
of Scotch Garnets. [ have some of these cut when in
fashion about thirty years since, and my friends have sent.
me some in the rock under the name of Pyrope. It is per-
haps one of the most striking examples of nice discrimina-
tion that may ever happen :—these may be distinguished by
the Scotch Pyrope having the lustre inclining to fine red,
and the other to orange*; and it should seem that they can
scarcely be distinguished when asunder.

Dr. Babington was so good as to favour me with the Py-
ope from Hungary. It is remarkable that it should never

* See red and orange in my Elucidation of Colours.

1292

he found crystallized, which is one of the specific cha-
racters.

Our substance is as remarkable for being rather particular
in the crystal, being the proper Garnet Dodecaédron with
bevillings on each side of the edges, which is not usual in
common Garnets. See the right hand figure. This is no
less remarkable for some being truncated at those solid an-
gles, or alternate corners, where three edges meet, I believe
not before observed. If analysis should show any material
difference, this will properly constitute a new species.
The crystals are in a gangue of Quartz more or less stained
with Oxide of Iron, part of it having a dingey greasy aspect.
The specimen was sent me from Ely, Fifeshire. It is said
that the Pyrope is found in the sand on the sea-shore near
the same place, and probably derived from the neighbouring
rock.—Might not loosened specimens of this bé found on
the shore worn so as to obliterate the appearance of having
been crystallized? and may it not also happen so in general
with those of Bohemia?

ve

7)
4, (et

123

TAB. CCCLXV.

ANTIMONIUM ' sulphureum.
Sulphuret of Antimony.

Class 3. Metals. Order 1.
Gen. 2. Antimony. Spec. 3. Sulphuret.
Div. 1. Crystallized.

Syn. Sulphurated Antimony. Kirw. 2. 246.
Grau-spiess-glanzerz. Emmerl. 2. 468.

Antimoine sulfuré. Hauy, 4. 264.

Ts Cornwall is found this stellated and spicular variety of
Sulphuret of Antimony. It seems to have the fracture
which is attributed to it by most authors, and is likely to
belong, as to its crystallization, to the geometrical figure be-
neath. It is curiously interspersed with small rhombic
crystals of Carbonate of Lime. This species is sometimes
of a fine polished steel lustre, and sometimes beautifully
iridescent. It may easily be scraped with a knife. The
powder is grey. It is easily fusible, wholly evaporating in

white fumes.

YMITY

a

ae
\

7 i‘ 5 : aA ue a
Eouenionnds af eoloatre et rei aa

ame

y

MLL.

ey Gt fou
“i pul tastied by, 17) Tine ry Lend nt

125

TAB. CCCLXVI.

FERRUM sulphureum.
Sulphuret of Iron.

Class. 3. Metals, Ord. 1.
Gen, 8. Iron. Spec. 5. Sulphuret.
Div. 1. Crystallized.

er EE

Tours singular formation of Pyrites, although of old in my
collection, is, I believe, new in description. Crystallo-
graphers say very little of the concave or convex rounding
of crystals of any sort, although it is ‘often a strong charac-
teristic of some substances, especially the convex, as in the
Diamond :—Crystailo graph y, part 2d, and Galeena, iad. 131
of this work, &c. Taceeecave ime however, much more
rare: indeed the appearance i is so extraordinary, that it has
been looked at more with an eye of wonder than investiga-
tion. The present specimens are examples of this concave
formation, and of the tarnish and iridescence which partly
disguise substances. They are nearly the same within,
although the smallest is so light-coloured outside, and has
a yellow, red, and blue iridescence; and the other nearly a
fair yellow metallic tarnish. This latter specimen also shows
the convex formation, which is so great a contrast to the
former that it is altogether a wonderful group, whether
caused by the solvent or quantity of material attracted for
ageregation. It seems to be an accumulated repetition of
this formation that represents the Cockscomb of the fol-
lowing table. We have, however, still some very valuable
and extraordinary specimens that primarily lead to this pe-
culiarity, of which we shall be happy to make observation,
as they are truly instructive.

126

TAB. CCCLXVII.
Cockscomb Pyrites.

I sevieve this odd variety is peculiar to England. Kirwan
(Ist edit.) speaks of it as crystallized in small cubes or py-
ramids, united to a common basis ‘like cockscomb.”
Dr. Babington and some others mention Cockscomb Py-
rites, but some of our late mineralogical authors take no
notice at all of it. It is said to be rare, excepting in Derby-
shire ; and as it is often very liable to decomposition, many
cabinets that once possessed it are now without it. Mrs.
Gent of Devizes was So cood-as to ‘offer me the use of a
finer specimen, that is to say, a specimen with larger
cockscomb crystallizations. Both that and mine are. pro-.
bably i in a state of slow decomposition, for they are dullish,
and have a sulpbureous scent, I suppees on account of the
Sulphur passing from them. “The: smoother cubical pyrites
and the striated have been conside ed by some as distinct
species, because one is more apt - decompose and fall to
pieces, as these and most others ie, do: this is therefore
scarcely a sufficient distinguishing character; and I have
most varieties in the changes by oxidizement, from the com-
mon brown to the red oxide, and I have British and Irish
specimens in cubes, both smooth and striated, resembling
those from the West Indies called Sargestum (about which
I have had many inquirers) ; and I think, by various speci-
mens which I possess of Oxidized Iron, that Pyrites under
certain circumstances loses the Sulphur and becomes a solid
red Oxide. The present specimen is on a gangue of Car-
bonate of Lime with some metastatic Crystals more or less
stained or coloured by the red Oxides. Thus they change
by degrees to distinct species at each extremity. This is
perhaps a good example to show the difficulty of arrange-
ment, and the infinite varieties ; and that we should be cau-
tious of indulging too much in little distinctions.

JANIE fil hed iY fit’ Aver ly Melon
/ 1 ;

Z
~~)

iy eae
Fare riatts pulled ty Fe Sserby Lowden

S)

So

To7

TAB. CCCLXVITII.
FERRU M_ quartzosum.

Siliceous Iron-Stone.

Class 3. Metals. Order 3. Mixed.

EEE

Many places afford Iron-stones, Geods, &c. See De-
scriptions and Plates 106 and 107*. The present specimen
is from under the Thames at Rotherhithe, where the Tun-
nel is perforated, in a mixture of Sand, Sandy Lime, &c.
It is remarkable for its branching, and in some specimens
so much so as to represent the more entangled roots of trees.
It is internally of araw brown umber colour, nearly compact
appearance, and may be scratched with a pin, giving a
whitish streak: externally more or less rugged, with Lime
and Sand attached to it. I have only one instance of its
being found elsewhere, and that is a larger specimen in the
possession of Mr. Smith, who is so well known to be con-
versant with most of the Strata of this Island, who found it
in Wilishire. The Iron in this specimen is in a low state
of oxidizement, and is intimately combined with Silex and-
other earthy matter, as with a little heat it becomes mag-
netic. Some of my specimens are the more extraordinary
for having little Geods about the size of hazel-nuts, with

* I omitted one of the usnal terms for Iron-Stones, which is Geods. The
term seems to be original with Sir Jubn Hill in his History of Fossils, page
541, where he describes them as “‘ crustated ferrnginous bodies, holding loose
earthy or arenaceous matter.”* He has made distinctions regarding more
solid coated varieties, &c. as Hetrop:ra, Empherepyra, &c.

128

a coat or outward crust nearly the colour of the shell of those
nuts, and an ochreresembling Roman ochre, moreor less loose
within them. Thus we have an use for the term or division
Imitative, from the resemblance of these to the branches of
trees and nuts. In many instances Nature’s works are so
extraordinary in these productions as to elude the nicest
discernment, and teach us that much experience is necessary
to prevent error.

His

129

TAB. CCCLXIX.

CALX carbonata.
Carbonate of Lime.

Div. 1. Crystallized.
SSS EEO

Carzonate of Lime is so abundant in varieties and mo-
difications of its crystals, that we shall select only such
specimens as show something peculiar or instructive. In
the present instance we exhibit it with longer prisms than
usual, which help to give it the aspect of Quartz, which is
so common with a longish prism. Some specimens, but
such are somewhat rare, are not far inferior in lustre and
transparency to Quartz, but, like Diamonds and other dia-
phanous brilliant subjects, would be best understood by
comparison. Perhaps the brightest Carbonate of Lime
would be, in comparison to Quartz, as cut Paste is to Dia-
monds; so that even the most experienced must try the
coldness or hardness, to help his judgement. The first
method would not hurt the Paste or Carbonate of Lime,
but the latter would damage them; and specimens have
now and then been hurt by trial. We have, however, the
form of the pyramid to judge by; for Carbonate of Lime
never has been found with the obtuse equiangular six-sided
pyramid of Quartz, or representing any of the numerous
varieties of it:—thus the structure points out a distinction
which, when understood, is discerned in an instant. The
VOL. IV. L

130

present figure, therefore, exhibits not only a rare specimen —
of Carbonate of Lime, but some varieties in the facets of
the pyramids. The upper figure is a small group with
pointed endings. The lower figure has the same faces with
lateral additions, and one is terminated at both ends. I have
added parts of two other varieties underneath, which occa-
sionally form groups. The upper right hand geometrical
ouiline shows one end of a crystal with a narrow face,
which is placed upon the acute edge of the pyramid. The
next outline beneath exhibits narrow faces on the terminal
edges of the prism, with a minute truncation upon the
acute angle, making three additional facets to each solid
angle: the obtuse end contains three of the primitive faces.
I have a group to correspond with the faces of the column,
alternating narrow at one end and broader at the other.
The right hand figure has an equiangular pyramid with a
truncated apex, nearly like Hatiy’s fig. 32. This is rare:
it is from Derbyshire.

131

TAB. CCCLXX.

CALX carbonata.

Carbonate of Lime.

Div. 1. Crystallized.

Syn. Chaux carbonatée contractée. Haty, 2. 148.

<a

A rare modification of Carbonate of Lime from Derby-
shire. The faces of the column being alternately broader
and narrower at the ends would, if extended, make an
acute rhomb, formed by a slight deviation from the law by
which the regular hexhaedral prism is produced. The apex
is formed by three faces corresponding with those of the
equiaxed rhomb, ¢ab. 13 and 128, rendered pentagonal, and
contracted as it were into narrow facets, by the broader
ends of the columnar faces which approach the axis in the
direction of the edges of the rhomb; whence Hatiy’s name.
It is generally found more or less covered with a brown
crust, and has a roughish aspect given it by a mixture of
earthy Oxide of Iron.

The lower figure is less acute, and has also the equiaxed
termination: this also is rare, and is coloured a little.

Both are upon tabular Sulphate of Barytes.
L@2

_sptnaodiss” iE a AD ‘

a Sad aie ea asi Yo" Sin sada

a a i Ss — git? s

al pd ein 3

Dia! ‘al oi!
atid 0 seo div 3a ibaoquarto> asaat, sind a
bas _— hoisbast Bet bes 28 S08) eared ”

i od} mi dine. ont ti doesn ‘sia mods sxaenulon, oft to ie |
ausa eyinlh gonotw § sdeaods oa Yo bagi oth) to hi f,

2M

sevrortd pie hareyoo aaal, xo stom bavuot eleven

Fo: oT KiD & % (a si-navig Jueqes daidyy on $. ad

~

Bet | i, hoasiupo art ovls ver! bos 808 esl af.
_ olaail £ bacdiomicat ai hae a ei a

if
Muy £4, Aulblushad by Jo Tow My London.

133

TAB. CCCLXXI.

SILEX Idocrasis.

Idocrase, or Vesuvian Garnet.

— Eee

Class 2. Earths, Order 1. Homogeneous,
Gen, 4, Silex. Spec. Idocrasis,

Syn. Hyacinthe var. 3 to 8. De Lisle, 2, 291.
Vesuvian. Emmerl. 3. 314.
Idocrase. Hatiy, 2. 574.

Tr is found pretty abundantly in a rock chiefly composed
of Mica, Hornblend and Garnet, on Mount Somma. The
present specimen was found in the county of Donegal in
Treland, in what has commonly been called the Garnet
Rock, whieh is usually gathered in fragments for the sake
of the Garnet, for which this was sent to me; and is curi-
ous on account of its colour. The rock is composed of
Phosphate of Lime, large-grained primitive gray Lime-
stone, Quartz, in some parts coloured green by Phosphate
of Lime*, and Garnet, among which is the Idocrase or
Vesuvian of some authors, because it was first known as
coming from that neighbourhood. This substance is recog-
nised in the specimen, by its prismatic structure and rather
darker colour, although lighter than usual: the Garnet is

* There are about the specimens several minute crystals of Phosphate of
Lime of a green colour, that bear some resemblance to Beryl.

134

irregular, somewhat more salmon-coloured, and lighter ; the
Phosphate of Lime nearly white, and the gray at the bot-
tom is the coarse-grained Limestone of the county, which
is generally considered as primitive. The whole rock is cer-
tainly a curiosity, if considered in a geological point of view.

The small upper specimen has the Idocrase of the more
usual darker and shining greenish brown, and the Garnet
is crystallized ; which assists in identifying it.

The crystal of the Idocrase is a rectangular four-sided
prism, with the lateral planes streaked and the edges most
commonly truncated. It is without its termination in my
specimen; but Haiiy exhibits a great variety of faces upon
the short or obtuse pyramidal apex. It has a resino-vitreous
appearance with very little transparency. It is hard enough
to scratch glass. Its specific gravity is from 30882 to
3°409. Melts with borax into a yellowish glass which ap-
pears red while hot.

Analysis of Idocrase, from Mount Somma.

AIUMINE| seu NOW bae eee

Silica’. o 4 a RAeeO 35-50

Hime. . 4 . 34:00 |.» 33°00

Oxide of Iron . 5°50 4 ee ee

Oxide of Manganese a+ ge 1 OLes

oss 7. ge ED as ee
Thus we add another substance to British Mineralogy.
The specimens were sent, some time since, by Dr. Scott
of Dublin, without determining it. I say no more on this
substance at present, hoping some time or other to see
more perfect crystals, with less confused fracture and ter-
minations, and also of the Beryl-like Phosphate of Lime.

Miyy
ry Rite ;
ahs

Ay s1310 publathe by, | fut Sinverby Liv

TAB. CCCLXXII

CALX _phosphata.
Phosphate of Lime with Garnets.

Div. 2. Imitative, (fibrous.)

SS

Tus substance, which I have received from the neigh-
bourhood of Aberdeen, by favour of several friends, as a
phosphorescent Granite, appears to be a fibrous Phosphate
of Lime with Garnets, either decomposing, or not so per-
fectly formed as usual, but showing plainly the Garnet do-
decaédron more or less interrupted by the Phosphate of
Lime. Mr. Jackson, F.L.S., found some at Tierbagger
and Culterby, on the Dee side, near Aberdeen, and it is
certainly a curious production, not mentioned in any
British or even foreign authors. If a fragment be placed
on a hot iron or poker, it has the blueish glowing phos-
phorescent appearance of some of the Fluors. The Gar-
nets in this rock are sometimes so small as to be almost in-
visible : sometimes they appear only in the form of irregular
blotches; but occasionally they are more regular and not
attached to the rock, but only fill up a dodecaédral hollow,
and have then the appearance of ihe lower figure, yet seem
to be much mixed with the substance of the rock. The
Phosphate of Lime is in small bundles of fibres closely
matted together, of a pale blueish green in the most com-
pact parts, but whiter and even brownish near the surface,
where it is in a decomposing state.

t

poems

te
¢
AC
ry

4
‘dads tose’ vad ¢ eid Aoahigat
SE a8 & pba leme | Mo worst vd

4

‘ns a ee yay
Oe ksi Nine neuen

age as tenet tis _coidnaaberney “adic ‘

: Wooly Ad S089 awe, 6 US eo aging it:
weashy shiv hg. itsiandd ade tcl. at anidod’ O. OM Moe
“hed: eat woot hess to: 9 Od Jo: somie' . ry eh

mitt Meenle od Of 26 Ie oF aginptiaieion pie doen aid sri i eae
‘spbigaviialg ot n ae vido saaqays vault eae T ROR ¢ oldie?

- oe

cn toa. bie wleger siom oia-yods vlfanoienoso jd ¢ a4

re

f

wollen lex baooosbobis qa Ht view ded * foo: ‘aeky of
i ;
Agora whi lo gonpresqa madd nok as

oft, ..door oft to somstedue ods ite
yiseola ede. to, xtitnd Vere ai at

seat roo henero sul) ai daaty deiauld slay Ye,

5 ones os w8e dai eruoorech wis7e ban 3 votishwr a

137

TAB. CCCLXXIII.
SILEX granatum.

Garnet.

- Div..1, Crystallized. Var. Trapezoidal.

i Hie ae,

Gannets in trapezoidal crystals are not so common as in
rhomboidal dodecaédrons and its modifications, for which
see tals. 43, 44, 120 and 364. They, however, occur in
some variety, as to the perfection with which they crystal-
lize; their brilliancy, and additional number of facets.
Like the former, they are sometimes detached from the
rock, or easily separated. The best seem to be most usually
in the least decomposed Granites. The upper figure is an
irregular fragment of micaceous Granite, of which the red-
dish part is Feldspar; the whiter part, Quartz; and the
whitest, Mica. The Garnets are of a good colour, and
have a tolerably natural polish: some are rather compressed,
and some have a face or four-sided truncation upon the
apex of the four-sided pyramid. The lower middle figure
is representative of those in the gangue above. The left
hand lower figure is a larger and nearly regular one, of a
dull roughish aspect, found detached, or rather having
fallen out of a somewhat sandy rock. The other, which is
larger, showing the truncation, was sent me detached, with
some other favours from Scotland, by the Rev. James Dal-
ton, and the former ones are from the neighbourhood of
Aberdeen.

138

Garnets vary much in size. I have one, with which I
was favoured by Lady Wilson, from Scotland, above an
inch in diameter, and they are sometimes larger; perhaps
they may be found equal to those from Fahlun in Sweden,
which I have seen very large; and I have one, a rhomboi-
dal dodecaédron, nearly five inches in diameter.

These specimens, with their gangues, will be doubly
useful when we come to treat of the Rocks.

ns

159

TAB. CCCLXXIV.

FERRU M sulphureum.

Curving or Bending Pyrites.

Dad . Imitative.

gi
Pernars 8 Veould not show any thing more extraordinary
or, I believe, more rare in the system of Crystallization, than
the present specimen which I possess by favour ‘of. my
good friend Philip Rashleigh, Esq., of Menabilly, who
sent it to me in 1806, labelled from Semele in EE
shire.”

Pyrites is well known to an the Cube and Octaédron,
with their modifications, | very neatly : see tabs. 29, 30,
99, &c., and to produce varieties from them, wedge-formed,
rounding, concave, and convex, cock’s-comb-like, &c.;
see tals. 366 and 367; and to mix in somewhat cruciform
and other odd appearances. In the present instance the
Pyrites seems more like Sheet Metal cut into pieces,
as if with a pair of sheers, curving in various directions :
thus we have an appellation of “ imitative’? to recognise
it by; which is very convenient in the present instance. I
do not know that curved crystallization has been at all
mentioned by any author. I should suppose, however, that
it depends upon the same laws of aggregation in this sub-
stance as the straight or rounded; see vol. 11. p. 57: and
the rounded figure in tab. 131. Its state while depositing

140

from the solvent, and the solvent, may account for immense
variety. This, however, is a very rare example, identifying
a new kind of form, and bespeaking another source of
boundless variety. The crystals seem to be formed of plates
belonging to the cube and cubo-octaédron, passing in a
more or less continued line of elongation, forming a sort of
wall-like appearance in various directions, and may perhaps
be compared to a tall weak wall on an irregular foundation,
bending before it was hardened by drying. The crystalli-
zation of Pearl-spar, tab. 19, lower jigure, which curves,
seems governed by a different law: the molecules seem to
slip while depositing; and the Sulphate of Lime, éal. =
seems to bend from an elastic property.

oN

hey Lele fal tha y gh Cr tl

141

TAB. CCCLXXV.

FERRUM oxygenizatum.

Oxide of Iron.
Class 3. Metals. Order 1. Homogeneous,
Gen. Iron. Spec. 3, Oxide.

Div. 2. Imitative,

S eeREEREEEEmmmense =... cee

‘Tue present is not only a new but an instructive specimen.
The crystals are secondary, but so perfectly distinct to every
observer, that their derivation is truly evident. The grand
vicissitudes and changes continually going on, even out of
our sight, become in this instance very evident :—were the
operations carrying on in our sight, we could not be more
certain of them. Hematitic Iron, see tab. 56, is shown
in this specimen, forming the concentric radii, in coats
one over another, having lain over metastatic crystals of
Carbonate of Lime; which being decayed, their place was
filled up by a fresh supply of Oxide of Iron, with such ex-
actness that the least attention to crystallization discovers
the process. The moulding or coating in this manner is
so sharp and accurate, that it may lead to a means of im-
proving in such arts, especially as it is evidently a wet pro-
cess, although it possesses so much the resemblance of fu-
sion, as to have been actually thought so by some; but we
herein see how the two processes resemble each other when
completed.

142

Three different states of Oxide of Iron are visible in this;
viz. the black-brown, the red, and the Roman Ochre; and
I conceive an indefinite number of Oxides may be formed
by the blending of these: nor do I think Iron is capable of
taking oxygen from water, &c., in these different degrees
which colour seems to represent; but when blueish or pur-
plish, or any variety exists, it may depend upon Carbonic
Acid, Hydrogen, Phosphorus, Manganese, &c., which
may be known by their external appearance.

370 »

143

TAB. CCCLXXVI.

CUPRU M nativum.
Native Copper.

Class 3. Metals. Order 1. Homogeneous.
Gen. Copper. Spec, 1. Native.
Div. 2. Imitative (wire-like.)

Pernars this formation would never have been expected in
Native Copper by the tyro in Mineralogy ;. and it is indeed
very scarce. The rounding branches irregularly disposed,
inosculating with their bluntish terminations and rugged
rusty appearances, might be taken at first sight for a number
of pieces of Iron wire agerecating so confusedly by means
of rust: however, in colour it approaches to Copper, and
may by scraping be easily distinguished, haying the softness
and red-metallic lustre. It is rather remarkable, that the
branches, if I may so call them, are sometimes so much
coalesced as to join pepereatly | in a continuous manner; at
others they seem attached, as if pressed one against another
and stuck together; and some parts of the sides and ends
terminate as if they once had been joined to others, some
being blunt and roundish, and others having a small con-
cave disk.

I have placed another branched specimen, having the
branches six-sided and somewhat irregularly cut, resembling
an endeayour to do it with a knife, and so are somewhat

144,

scalloped, partly concave and generally rather flattish, with
two sides broader than the rest; see the right hand magni-
fied figure at the bottom.

[ have placed another peculiar ramification at the bottom
on the left hand, showing more of the nature of structure
depending on the order of the crystallization, more or less
zigzag or feathered, which is shown more distinctly in the
magnified figure. The whole are very small, but indicate
the rhomb, tal. 216, and the dodecaédron, tal. 25, which
are almost recognisable: the rhombic accumulation is
pretty evident, and the angles of the zigzag appearance are
the corners of the rhombs. Moss Copper generally belongs
to this variety.

The specimens are from Cornwall, but the upper one is
the most rare: such are much valued.

145

TAB. CCCLXXVII.

SILEX quartzum, var. opalinum.
9

Opal.

I wave given (Brié. Mim. 111) a figure and description
of the Precious Opal of Cornwall. I now show a variety
from Sandy Bre, brought from thence by Humphry
Davy, Esq. of high chemical celebrity. Opals have been
divided with some difficulty into several kinds; as The
Precious Opal, The Common Opal, Semi- or Halb-Opal,
and Wood Opal. The good and bad might have been
sufficient distinctions, as the several kinds run into each
other. The three first arrange according to their good-
ness; the Precious Opal having a pearly brilliancy with a
fine soft display of most of the prismatic colours, and a
brilliant lustre peculiar to itself: the Common Opal has
less of this lustre; and the Halb-Opal borders on it so feebly
as to be considered as only partly an Opal: the Wood Opal
may have all these varieties, but is infiltrated into the re-
mains of wood retaining its structure. These distinctions
therefore do not all belong to the substance, and become
incorrect, or mislead. The present specimens are remark-
able: the upper one, for a fine somewhat resinous appear-
ance, from a light dull greenish yellow to a resin brown,
with a fiery or orange yellow sparkling splendency reflected
as the light passes among the flaws.

The upper specimen is ina sort of decomposing Porphyry,
spotted and veined with resin-like Opal mostly dull in colour.

The lower figure has something of the appearance of light
VOR. LV. M

146

Burgundy Pitch, and is such as is often found in the ligni-
form state. I have an example in a foreign specimen.
mingled with Pitch-stone.

Opals are chiefly Silex with from 5 to 10 per cent. of Water,
and, under certain circumstances, are so operated upon,
that moisture and change of temperature more or less sud-
den 3eem to cause the various appearances ; and those that
become degraded below the Precious, are less and less pure
with various adulterations. Generally found in more or
Jess perfect Porphyry.

Analysis of the Opals:

Precious Opal. Common Opal. Semi-Opal.
Silica - - 90° - - 93°50 - - 43°50
Oxide of Iron — - - 1°00 - - 47°00
Water - - 10° - = S500- - 7°50
Togs © Pe cp me 50 - - 2:00

100° 100°00 100°GO

37a

g) autited
( In) 4 1QOfUL

147

TAB. CCCLXXVIII.

ARGILLA electrica.
Stellated Tourmaline.

Tue different appearances that various substances assume
is the greatest stumbling-block in Mineralogy: it becomes
therefore necessary to Jearn them; and although forms under
the same terms may belong to various substances, they are
nevertheless often characteristic of particular species. The
present variety, although not common, is pretty well known
among the Cornish miners, who call it Cockle, which is
generally recognised as Schorl or Tourmaline by mineralo-
gists. See tab. 209 and 210. We may find specimens that
lead from the more crystallized form of those of the fila-
mentose structure through a great variety of arrangement
to the present stellated one, where the crystals shoot as it
were from a centre, are thin, and interrupted in their forms
by pressing among each other; so that externally we guess
at them from a similarity in appearance to those of a more
conspicuous size, generally angular, and mostly shining and
longitudinally striated on all sides. If experience does not
determine them to our satisfaction in this, we must proceed
to hardness, electricity, &c., to find their correspondence.

Our specimen is rather remarkable, being in a gangue
chiefly composed of Mica. I have a specimen from Aber-
deen nearly like it; but the Schorl is chiefly imbedded in
Ouartz, and a mass of Mica attached to the specimen has
only a few scattered bits in it.

M 2

colleen ba a

. } A i,

Cie eoltinels. are 0 OMA.

a ie nist eigee eadot gots
rae ils weld eh. 10 OaORY + ty
ane ‘Inomiagestia HN tas siete
#1 ee t00 iia elise
4 : arciut wots i} bysten
es 290, 97 yilonias x3.
ee ae lio? sae?
i? ie baa y i inirte rise nb i Eee Ae
Blo) gee seb gonsitmges 1 .eabia ee $ iO borne vilecibesigerel ,
ae 1 -peesorg fer aw Letts rte q0it2e eLlee AO 08 eeroel sacral :
i + .2onelRoGKe 1109 sia? bait of aks qin ayty eesaland ot
ity, 1, fangneg +e gal a3 dasianat AIR Bi omioge 0
ae wad A Mon aIM joaqe & sy net i — pene
pebhodari yAsido at in
ted nomosge as oO} sien ante

A
ry bs
oh Sats

“se

@ i

149

TAB. CCCLXXIX.

SILEX fragilis.
Brush-like Actinolite.

‘Tuts curious and remarkable variety is not uncommon in

some parts of Scotland, and further north. Its laminated

structure and softness will pretty readily distinguish it from

Schorl, which it has been taken for. The upper figure
represents the opposite side of a piece not much unlike the
lower specimen, and is composed almost wholly of Actino-

lite lying in confusedly parallel order, with an oblique
whitish streak looking like a vein: the rest is mingled with

dull and darkish greens: one end shows its scopiform ap-

pearance: on the other side it is more crowded than in the

specimen below, which is more schistose, composed of light.
gray fine silvery Mica, relieving the curved brush-like lines,

formed by the somewhat twisted bundles of actinolite, which
are rather dull greenish black on the surface, but shining on

the sides, and nearly resemble the end fracture of the upper

specimen. I received this and some other interesting spe-
cimens from the north of Scotland, by favour of my good

friend James Brodie, Esq. formerly mentioned in this work.

It was gathered by the Rey. Patrick Forbes of Boharm in

Scotland.

i ie ; iy a

ace (21999. ART

a

‘ sionitoh, oiler 2

ailige

fs hy uc

i a

ee anath | ty alvin tan os a i ri aa

a,

; : “telgil tol sane. aeore
onl He diasid Baris:
ane a tloidw aike MI SIB to eolbcud beteiws 14
a vite no aicite wd .99 sive oct no adsl d deingnng ilab. ae
1 (>) + qwaday ahd Bo erovoRt? bas ers sideman ehinaa | ite chia
~oqje grabeviadey voddte seni a be aids | 7 DF I
: i booy ent to word? vd ‘Sealoatt 1 to dette ort noid
oat ~ x how eit ni henoitaset given? :patl iba )

Ri mudoll to exdio% F doinss vo iff vd

an ee

151

TAB. CCCLXXX.,

BARYTES sulphata.
Sulphate of Barytes.

Div. 1. Crystallized.

SS

Tus figure leads from nearly the primitive thickish rhom-
poidal prism to the flatter plated crystals, which are piled
by the side of each other upon one of their most acute edges,
(see tab. 70,) consequently giving it a very different appear-
ance from the right-angled plates more usually seen, as in
tab. 72, the edges of which are parallel to the diagonals.
The crystals upon this specimen are mostly truncated upon
the acute solid angles, the truncations forming little trian-
gular facets; and they are all so deeply truncated at the
obtuse solid angles, that the truncations meet. Tab. 70,
bottom figure, shows one of these faces; and Tub. 95 ex-
hibits both.

This specimen came from Dufton. It is convenient here,
as it partly leads to those flatted primitive forms that stand
on the acute edges and are often very thin, without any de-
crement on the angles, but occasionally passing by minute
degrees towards an elliptical form, produced as it were by
being placed by the side of each other when forming, but
slipping or falling a little out of the parallel with those above
or below. This sometimes seems the cause of the curved-
like appearance which happens in Sulphate of Barytes like
that of Pearl-spar, tal. 19; more particularly when the latter
is a flatter variety. The weight and pearly lustre will, how-
ever, most generally distinguish them, The next figure
partakes of this appearance.

me eh Fe oa eee ah sf
ae 2 aT vA x i
Sis rahaane

Ja) as r \ ;
, Si be :

ep hoped es ifs ovinicndicg adh
ie ta via SiK i ca selanga
czoN 10-91 Se teen Wg

win wags t ie id
i888 a Hgigess:
saancgsib anh: vk tan

S

eer ata HCL hvat bit,

3 Fh 4 ie sae oe
973 tle Heats REE

bawia, 101F dhont wiring

+= 48
ie Tal

fi fighh eae

wb ysis tnodiakgands yin? athe or ei ay
wf otneeadS rin abe 1enodO tad .29heab on? BO ‘1nettaIs

h ae wo Stow J: eh Doan bond aheriat Ait { qth: Bi dnswos aadigab-
; to obix odd yd byoelg ya

ms

gud pificerial noe re dio dog aly
xe ‘yvods anode dtewtathesg vi. to Huo obiti is poiiliat- 1 gatgaile,” 7

a t J . ae . mr Biv wis wat a

ty ea ADOT tL ar Oo ok - otis RTGS 29s TSoe ‘t

Pat z ; ay, ae, : dias ee

sites > “oid estvisll to stage si snsgqed fouiw

Se etal aa) evel iw YNEIUOSEY PIO | RS ge x
\ § . ai ‘ 7 3 4 tr

‘ r 5 .

he etteod flew enent vheog ite 2 aye

sah jxots od Tui) 1 sings tise

-s

FEL

4p

‘

=
y
<
3
:

Om LION Hahn

TAB. CCCLXXXI.

BARYTES sulphata.
Sulphate of Barytes.

Div. 2. Imitative, Stalactitical.

<< re

Tuese crystals of Sulphate of Barytes are placed upon
their acute edges; they are for the most part extremely
flat, so that the column is as it were lost in flatness,
and the form is in some parts less easily understood, as
they are crowded very much, and strangely grouped into
hanging and curving forms, and each individual crystal is a
little rounded. The present specimen is, I believe, as rare as
it is curious, as we could less expect a heavy substance
like this to have such an appearance among the groups.
Some have an apt resemblance to a parcel of petals, giving
the appearance of a corolla or flower. See the lower figure.

We need not wonder perhaps at any general appearance
of this substance, when we see how it sports here ; yet it is
necessary to know that it has many odd appearances which
might be attributed to something else.

TAB. CCCLXXXII.

Sra vacTiTICAL Sulphate of Barytes, as far as we know,
has not been observed by any author. I have therefore
introduced it as one of the curiosities that was in Mr. Day’s

154

collection. IJtis from Matlock in Derbyshire. It shows a
curious state of aggregation, crystallizing after solution,
running and dropping in very elegant and varied forms.

The crystals sometimes line the tubes and nearly fill them
in a concentric manner like the common calcareous stalac-
tites: the tubes are often nearly empty. The outsides of
the tubes are covered with somewhat globular aggregations
of sharp lenticular crystals, some of which have yery much
the appearance of globular crystals.

tub puto py erik
WN MOUINOOMY MOC AMELIA

B83,

MESEMI I a fy Ae er aay
tah ly J “Auer Londen

155

TAB, CCCLXXXIT.

FERRU M sulphureum.
Sulphuret of Iron—LIron ea BLE8~:\ 9

Div. 1. Crystallized.

Prares:366 and 367 dreteurious anes of the erystalli-
zation of this substance. ‘The present extraordinary speci-
men seems to elucidate somewhat of the origin of those
modifications from the cube. See the right hand lower figure.
Two of the horizontal edges at each end of the cube are
replaced by rounding faces of such extent that they meet
each other in a line, towards which the vertical faces are
enlarged at the same time that. they hecome concave (see
the right hand figure): three of these crystals are grouped
together to form the left hand figure, thus disguising the
cubic structure. These and various other intermediate forms,
depending upon such a process, are on the specimen, that is
to say, one independent crystal, another notched, or one
joined as it were by one of its concave sides to another or two
others, not more, with the mutual loss to each of a concave
face, forming a straight seam, while the other sides are more
or less concave or straight, same as represenied in the figure,
with the striz of aggregation on the upper part, as I shall
call it for distinction sakes; the whole appearing as if formed
from a centre into three wedges. The crystals on this spe-
cimen are remarkable for their thickness, which much facie
litates the study of them: as they become thinner, they

156

,

generally group in greater numbers and with less regularity,
thus forming the Cock’scomb Pyrites above referred to in
tab. 366. The crystals are much elongated, and some of
them are joined by their cenvex faces, forming deeply fur-
rowed groups, not notched plates.

The gangue of this specimen is octaédral Galena coated
by Cubic Fluor.

TAB. CCCLXXXIV.

Tus is‘’a modification depending on the same laws. of
ageregation as the last; but the notches are filled up by a
continuation of the striated faces: the crystals are much
compressed, and often very thin, haying the appearance of
hexangular plates, three sides of which stick deep in the
gangue: they however terminate more or less solid in two
or three angles only, against each other, or in the more
massy part of the Pyrites. This Pyrites alternates two or
three times with the Quartz.

11810 fue itil ly fit 4 Ate? by Dude

157

TAB. CCCLXXXV.

CARBO bituminosus.
Plant-formed Coal.

Div. 2. Imitative.

rr

No subject in Mineralogy is more deserving of the attention
of mankind, or is perhaps more instructive, than the forma-
tion of Coals; whether it bespeaks the contrivance of a flood
as necessary for their formation, or proves that they are in
the great bulk, at least as far as we are allowed to penetrate,
dependent on principles passing through organization. Nor
is it the less curious, that while we have appeared so long
ignorant as to the nature of the subject thus returning to an
inorganized state, yet every day some fresh assistance meets
our inquiries, as we are allowed to improve them by an in-
dustrious research. The present specimens are proofs of
the eminent beauties constantly observable in the variations
of Nature; and while they show an analogy to our mo-
dern system, yet present us with Genera and Species so
foreign, that we are at a loss for comparison. The front
specimen is the cast of a stem of some plant which is co-
vered with a very regular arrangement of squamz, such as
remain occasionally after the old leaves are fallen off as the
smaller branches advance. The squame are very perfect in
appearance, and are arranged in spiral order; in some speci-
mens the spire winds to the right, and in others to the left :
those on the right hand side of the specimen tigured have an

158

embossed centre, and an apex somewhat thickened, and ap=
proaching the obtuse triangular scar that the leaves of many
plants leave after falling off, with the decurrent swelling
below. The nearest approach to this regular lozenge for-
mation is in the small branches of some species of pines,
Euphorbize or Protez. From the larger flatted impressions
and the smaller branched ones, it should appear that this was
not a very small species of plant. I have a flattened im-
pression that is seven inches wide, and this specimen is
smaller than some others which I haye, but was chosen for
its having the divided end, showing that the plant branched,
besides the sign of the two pith-like round holes, one for
each branch, remarkable for being on one side in these, as
well as in those not branching. The hollow is generally
longitudinally striated.

The other specimen shows a smaller branch, with some
remains of leaves which are a little carinated, acute, in
length about twelve or sixteen times their breadth, and
swelling a little from their base.

These specimens are both Ironstone, upon which the
coaly remains of the plants are impressed. In the front
spectmen, the Coal has the usual fracture, and is about the
tenth of an inch thick where the squame are most distinct,
as one side has only little regular embossments, the squamez
heing obliterated by sealing off or wearing; or perhaps they
were never so perfectly formed, on account of their being in
a position less fitted to preserve them: this ought to be
noticed, lest in some instances it should lead to mistake in
the species.

Other species of similar construction are found at Lord
Middleton’s, Woollarton, near Nottingham. I have, among
other remarkable ones, some much branched, by favour of
Thomas Meade, Esq., from Poulton.in Somersetshire.

159

TAB. CCCLXXXVI.

CARBO bituminosus.

Bituminous Coal, containing Animal Remains.

Div. 3. Amorphous,

Coat is now much more universally understood to ort-
ginate from the vegetable decomposition than when J com-
menced this work, and my figures in éals. 187, 188, 189,
385, &c., appear to place it out of doubt. It however does
not exclude the probability of animals at the same time de-
positing their proportion of Hydrogen and Carbon in similar
circumstances of decomposition, under pressure, and caught
when more or less in full life and perfection, and fittest to
form the more perfect Coal. Animal remains, however, like
the vegetable, can in this instance be detected only by the
stronger parts that appertain to either: the latter by impres-
sions, casts, &c. in the more earthy substance that enveloped
them while their juices were infiltrating by means of
moisture and their own more volatile parts. The former is
somewhat more rarely detected in the coal formation; the
actual remains of the more earthy parts, however, attending
their structure forming moulds, &c. Thus analogy teaches
us that the more volatile parts, like those of the plants, are
infiltrated into the Coal.

The present specimen, having the shells actually among
the Coal, is so presumptive a proof of this, that we have no
hesitation in considering it as a confirmation; and as we do

160

not often find the actual remains in the Coal formation, we
conceive it very proper to give a figure, especially as the
shells are in such perfection as to be known outwardly
nearly as well as if they were recent. As far as I could
detach the coaly matter, &c. from the inside of one, it
seemed to have no more hinge than Mytilus cygneus of
Linneus, which it greatly resembles, but it is a thicker
shell: it does not strictly accord with any modern one that
I know, I shall therefore call it Mytilus crassus. The shells
are composed of crystallized Carbonate of Lime, in some
parts rather transparent. The specimen has other Carbonate
of Lime in the crossings and small partings, with some
argillaceous Oxide of Iron. The coaly part is mostly bi-
tuminous, and has the fractures corresponding with it. Jt
appears to be found in Jarge compressed layers, with innu-
merable quantities of shells of this sort only. They were
called petrified Oysters by the miners, who found them in a
¢tratum above the Cannel Coal near Wigan.

[ at present know of no others so absolutely in Coal. The
usual Ironstone that accompanies Coal has ‘many species
of shells, which however seem to accord with the Mya of
Linnzus.

161

TAB. CCCLXXXVII.
SILEX quartzum, var. fibrosum.
Fibrous Quartz.

Div. 2. Imitative.

Sir Joseph Banks* the discoverer, and many others who
have been surprised at the regular pediment and archi-
tecture formed at Fingali’s Cave, now so well known,
would again be surprised, were they to see the present
specimen of the same dimensions. As a representation
on paper, however, only gives a diminished figure, this,
in that respect, only wants the idea of largeness to he
annexed to it to equal that in grandeur.

Here we see what may in common be termed coarsely
fibrous Quartz, the fibres lying in a vein in a Schistose
Rock stretched more or less regularly from one side to
the other, connecting the two by these filaments ; a very
curious circumstance, and little noticed before this in any
Mineralogical work.

Besides the instructive point in which the upper specimen
may be viewed, the picturesque structure which represents
a ruined Temple also points out a new and most natural
order for Architecture. Tie upper part represents a rude
and heightened pediment, witha sketch of radii placed be-
hind a bust, which is roughly but elegantly sculptured, as
if for a sign to point out to whom the building was dedi-
cated. The cornice is in a somewhat stalactitical form,
giving much effect by projecting forward so as to show the
stalactites partly in the shade beneath, which, in tolera-
ble order, hang lower and lower till a less projecting cor-
nice is as it were formed, with various openings, orna-
menting the space between like Attic windows elegantly
contrived of oval and other forms. Beneath this cornice
are the main columns in varied proportions, arranged so
as to admit light to the interior, and finishing by gradually
swelling into a sort of base on the lower cornice and on
some of the columns,, giving a good hint for order.
There are some bright octaédral crystals of Pyrites, point-
ing out judicious places for lamps.

* Who first made known the description of Fingall’s Cave, and furnished
Pennant with the account,
VOL. IV. N

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162

TAB. CCCLXXXVIII.
SILEX quartzum.
Striped Flints.

Div. 3. Amorphous.

Scorcn Pebbles and Agates are most commonly known
in beautiful variety of concentric circles or lamine, and
have been in high estimation in jewellery, and still conti-
nue so. See tab. 160. Striped Flints are less known; al-
though not very uncommon, yet more rare than the
above, especially when the stripes are in circles, or con-
centric; and they are only valuable for information, and
have in general less variety of colours and probably of
substance.

The upper specimen is from King’s Weston, near Bristol,
and consists of more or less condensed Flint ; the dexser
parts are the darkest, and the lighter more or less porous,
and occasionally coloured of an ochraceous hue. The
present specimen is remarkable for having a hollow cen-
tre, and the circles being so extensive that when broken
externally it of course appears as if there were many cir-
cles andcentres. F'lints of this nature and of a larger
size are found at Woodford in Essex.

The lower specimens are such as are found in the Gravel
near the Chalk Pits at Charlton, Plumsted, &c. These
are sometimes apparently parts of the larger sort, and are
more or less rounded by attrition, consequently showing
a later time than that of their formation for being depo-
sited in their present situation.

The stripes in these instances seem to depend upon a
deposition of the parts while supported by Marle or
Clayey Rocks, and not upon laminz falling like strata,
one part imposed upon the other:—the lower pebbles
were thought to be of the latter construction.

Tee TELL pulladhied yy fo Mitverly Sabin

ttleabed Iu fe ver bendlr

163

TAB. CCCLXXXIX.

SILEX electricus.
Pointed Schorle.

Amonce the many forms that this substance assumes, and
not rarely, is the present; but it has not yet been described,
to my knowledge. It is composed of elongated prisms, a
smaller or greater number of which commencing at a point,
often diverge to great lengths, thickening more or less regu-
larly, as figured. I have them mostly six-sided, with some
of the angles here and there truncated longitudinally, so that
some have as many as twelve sides, giving the appearance of
a peg cut in angles and left without being rounded. I ex-
pect they are often of great length: what I have are only
about three inches long (sent me by the Rey. Patrick Forbes
lately mentioned), but these have no terminations. They
sometimes, however, end abruptly, as the hollowimpressions
show: they sometimes also have a transverse crack, which
is filled up with Quartz. Indeed it does not appear to me
that any one has yet made a research for the purpose of in-
vestigating to what length Schorle may shoot or lengthen:
perhaps this may be a hint towards some attempt of the
kind; which, however, is the nore difficult as it is so frequent-
ly among Quartz in the hard Granite Rocks: when, however,
it is found among the more micaceous parts of it in veins,
it may be better traced, as in such situations it is often very
long, but perhaps seldom so perfect.

I was favoured with the upper specimen by the Earl of
Seaforth, from the neighbourhood of Portsoy in Banffshire.
In it the Schorle is passing through or among Felspar or
Kaolin and Quartz, leaving its impression where it has be-
eome detached, which is often the case, as in some parts it

164
\
is almost loose, with Mica interposing between it and the
Quartz. I add the lower specimen as a remarkable variety
among shattered Quartz, diverging and divaricating in fas-~
ciculated prisms almost approaching to spiculz; the prin-
cipal Quartz fracture being on one side or at right angles

with them or nearly so, as if formed in another direction.
This is from Aberdeen.

TAB. CCCXC.

Wuen I was at the Logan Rock, well known in Cornwall,
I gathered this specimen within a few yards of it out of a
very large solid massy vein of Quartz. It ran some length
into the Quartz, but owing to my want of time and tools I
could not ascertain how far. This specimen is of a close
hard texture, and finely polished, which approaches what
may by some be called the Tourmaline variety; it has a
slight greenish hue when viewed so as to transmit the light,
and is more or less covered with the prismatic iridescence.

<

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ie — ae
[Als Ok ay CA
" eagteresae) ue ert

FOL

ee VE OY li be
AME Mig fl Vp neleg-ton tin

105

TAB. CCCXCTI,

Sb, EX: Mica.
Brown and Black Mica.

\

Tuts substance may be found of almost all colours, except
blue; at least there have not yet been observed any speci-
mens of that colour. The darkish brown variety, figured at
the upper part of the plate, is not uncommon in small specks
or specimens in Granite, but rather more rare of a larger
size: the group is not as usual convenient for dividing into
plates, but is seemingly a congeries of scaly crystals ar-
ranging in a peculiar angular manner, sometimes according
with the angles of the primitive rhomb, meeting and min-
gling so as to hecome quite zigzag, while the accumulated
planes are diverging from different centres in confused order.
Its colour gives it rather the appearance of thin horn, but
it has a more glassy lustre.

The lower specimen is rather rare, being of a true shining
black, z. e. black without any mixture of brownish, blueish,
or any other colour: it has a more glassy lustre than the
upper specimen. The congeries of plaies on one side of the
specimen are smal! and on the other larger, more continu-
ous, partly undulated, and altogether less orderly, and not re-
gularly enough grouped to need particularizing.

Common brown Mica of the shops is often two feet or
more square, and when used very thin for microscopes ap-

pears nearly colourless.

ergs i MEF

yee j
ty in : rua

sei EVE fi

Cait VRSY ORE 129

167

PAB» COCNEI.
PLUMBUM sulphureum.

Slickensides Galena.

Div.2. Imitative.

‘Syn. Spicular compact Lead Glance. Jameson 2. 355.
Compact Galena. Kirw. 2.218.
Slickensides. Bab. 170.
Plomb sulfuré compacte. Hauy 3, 461.

mea TE

Tuts variety of Galena, rare in any country but England,
is found chiefly at Castleton in Derbyshire, and 1 have some
specimens marked Ecton Mine, which is partly in Stafford-
shire. It appears to be the common Galzna, but, by a
certain slip of two faces as it were of a separated mass of
rock, is pressed into a finely granulated compact appearance,
quite losing the regular cubic fracture, otherwise usual to
Galena, and which so essentially distinguishes it from
most other substances. Sometimes this is rather massy in
the interior part of the specimen, near or quite adjacent to
the polished face, caused probably by the broken ends of
strata slipping and pressing against each other. It may be
on the face of mixed rocks, on Fluor, Quartz, and Sulphate
of Barytes. Itis said to be dangerous sport to the miners
when they meet with it unexpectedly, as it is easily detached
with a sudden explosion, and is thrown with such consider-
able force that it has even been fatal to those that are within
its range of action; but when, as by experience, they have

168

learnt to discover, by the sounding of their tools against the
spot, that the next stroke may detach the slickensides, they
stand beneath, if the situation allows, and, advising their
friends to arrange themselves in safety, spring the mine as it
were in triumph. I presume that the compressed air, allowed
relief from a space so broad and suddenly coming into con-
tact with the common air, causes the noise, and the expan-
sion impels the stones to a proportionate distance, and frag-
ments fly afar over the operator’s head, who has a reasonable.
cause to triumph, as his knowledge has taught him to make
sport with safety where he might have suffered by ignorance.

The specimen figured in the front of the plate is from
Ecton Mine, where so many brilliant coloured and variegated
specimens of Pyrites occur; and this is not a common va-
riety, because it partakes of the splendid prismatic colours
added to the highly polished surface. The piece figured be-
hind is more usual, and at first sight very much resembles
the Free-stone of a chimney when shining with common
Black Lead or Plumbago, which sometimes by means of |
smoke has the iridescent or prismatic colours, but in this
it does not resemble it, This specimen has Mineral Pitch
and Pyrites about it in veins.

Other substances are liable to be polished in the same
manner, and apparently from the same causes.

393

iT it

fw watt published y / fa’. taverby Lowtun ;

169

TAB. CCCXCIII.

“

SILEX quartzum, stellatum.
Radiating or Stellated Quartz.

Div. 2. Imitative.

ae ere ier

Tus has long been esteemed as curious, and is perhaps.
nearly as remarkable as the Corsican Granite*; which, al-
though differing somewhat in the contents, nevertheless
leads towards a similar construction, and may be as difficult
to account for. This specimen also much resembles the
Carbonate of Lime, represented at ¢ab. 144. It is yet the
more extraordinary, as it is a large separated almost insulated
stone lying on the surface of a field at Scorrier-House, be-
longing to our kind friend Mr. Williams, where it is only
known, and to whose friendship I am indebted for the spe-
cimen showing the crimson, amethystine or pinkish Quartz.
With the other specimen I was favoured by Phil. Rashleigh,
esq.—It is somewhat imitative of some of the Hzmatitic
Iron Ores, which have many centres, and radii of different
lengths. See tab. 133.

* Which will be figured ere long in Exotic Mineralogy.

VOL, IV. 12)

HOZ090 GAM

ty
»

B tigeguis 4: 4: getter te Patio

296.

Feb plllshed by fut Aoveds L utter

TAB, CCCXCIYV.

SILEX Mica.
Silvery Mica.

I the description of tal. 80, we noticed the difficulty of
imitating the lustre of this substance; but having found
means of partly surmounting that difficulty, we are happy
to produce examples in the present figure. This one is a
curious aggregation of laminated crystals, if I may so call
them, It is also very remarkable for being one of the first
examples of Mica showing an inclination to mackle. In
the present instance the plates are chiefly ageregates of
smaller rhomboidal ones; the mackle forms by the sides
of the rhombs being contrary to each other, like some of the ~
Gypsums. See the lower figure of tab. 223, which seems to
depend upon similar laws of crystallization. |

This is sometimes found in very large masses. I have
specimens six inches long from Aberdeen.~—Schorle is oc-
casionally included in it.

I have lenticular crystals of this substance in an ordinary
specimen, which, as they certainly are but little if at all
noticed, I mention here. They are seemingly formed of
the laminz placed a little irregularly edgewise, resembling
the lenticular Sulphate of Barytes and some specimens of
Talc, which latteris however generally smaller, see tab. 182,
where they nearly approach this figure, or rather in ¢ab. 74,
under the name Chlorite: see description, p. 154. Ido not

172

doubt, now that it is observed, but that it will be found not
unfrequently. The specimen was sent me as gathered near
Aberdeen by a dealer without any particular observation,
but I could not let it escape unnoticed here. The specimen -
en the whole is rather dull reddish brown.

“It. i

a
=

a ¥

| The Mica. tae =A

A i

%

‘Luis is a group of almost hexaédral lamine, bie very
confused, and as it were compressed with layers of Sandy
Quartz, &c. intervening. Its lustre is often so truly me-
tallic that it is like thin plates or squamz of Gold, nor could
we represent it without metallic aid. a is perhaps chiefly
coloured by Tron Ochre.

This specimen was brought from Aberdeen, and partakes
somewhat of the nature of Gneiss.

EY Mbtis/sed, yy, fa" Hinverly ad

7

Febssupubtished ly Je Tassel Lebar.

dA Bes CCCXCVI.
ZILNCU™M sulphureum.
Sulphuret of ZINC

Div. 1. Crystallized. Var. Dodecaédral.

“Vs substance has so many appearances, that it is of con-
sequence to identify some, even of the ruder-looking ones,
which, after the neat examples figured in fabs. 74 and 75,
are hardly to be recognised as belonging to the same sub-
stance. The present, however, is not an unusual appearance
‘of some of the massy varieties, and is representative of the
primitive rhomboidal dodecaédron, and the same as the.
fractured nucleus. It is altogether such a heap of small
indistinct appearances, that one can scarcely recognise
the, parts showing what forms it belongs tos; nevertheless
with a little attention rugged dodecaédrons may be ob-
served. It exercises the early mineralogist in the study,
and stands with the more experienced as’ an instructive
lesson in the variations of Nature’s school, always to be
esteemed for characteristics descriptive of herself. This and -
the following figures serve to show the principal varieties of
crystallization, which continually form more or less com-
pounded forms and groups, that will occasionally combine
so many modifications in one, that it is very difficult to
comprehend them. | '

There are some varieties in colour (as may be seen in a
slight degree), such as a fine orange brown and yellow, trans-
parent and brilliant, but generally in stnall crystals. It is
the resinous variety that is phosphorescent, or gives light
when scraped in the dark, some say with a brass pin; but
I have some by favour of Mr. Pennant, from Flintshire, that
is so when scraped with a knife.

This-ore is often used to procure the metal from.

TAB.” CCCXCVIT.

Brack Jack, as this substance is commonly called by the
miners, is exemplified in this specimen with the usual ap-
pearance, and is indeed black to a proverb, for I know of
no substance that has a blacker aspect. Coal is perhaps
even blacker when powdered, in which state Jet is brown;
but this, which is full as dense and brilliant in the mass,

17

scrapes nearly to white dust, viz. light yellowish brown, not
much unlike rosin, which gives a whitish dust. The splen-
dent black crystals are generally grouped as well as con-
fusedly crystallized, showing their brilliant polished facets
one at a time occasionally very distinctly, but in the group
are merely jumbled masses. As they often form among
white Quartz, they are the more richly relieved; and the
present specimen is additionally so, by the pecuiiarity of
some of the Quartz, which is found to be, when examined,
beautifully crystallized in relieved six-sided crystals, termi-
nated at each end by six-sided pyramids, but they are again
covered by. an opaque, very white, almost mealy coat; or
perhaps, having been acted upon externally, have become
opaque by a division of the particles, which on that account
are so separable as to be scraped with a steel blade of a knife.
Specimens with a thin coat of Chalcedony next to the
Blende, and transparent Quartz above it, are less rare.

TAB. CCCXCVIT.

‘Te various circumstances which attend a mineral are very
convenient to be known: [ therefore have figured Sulphuret
of Zinc in one of its usual scattered appearances, and with
the seeming irregular crystallization common to it. It is
in tetraédrons, nearly as the geometrical figure of tab. 74,
more or less formed of smaller crystals with little shining
facets, or very dull, very different from those fine smooth
almost steel-like polished crystals in tab. 397.

I chose the present specimen, as it would elucidate some
other subjects if attentively considered. The matrix is
chiefly Quartz, which has probably formed over Cubic
Fluor, in a very loose and rough manner, as may be seen
by the impression ; and after the Fluor was gone, Galena
or Sulphuret of Lead has formed ina scattered manner about
it. This Galena has, however, mostly passed away, and left
Brown Pearlspar in thin walls, which, having covered the
cubes, are at right angles in the various positions in which
the Galena originally lay.

Thus may be sten the changes wrought underground by
means of various agents; and thus we have continual proofs
of chemical agency, which perhaps may lead us to inqui-
ries that may be of considerable importance, while the seb-
ject thus come to hand is an example too curious to be
passed over at a time when investigations drawn from Na-
ture are found to be the truest mode of inquiry and im-
provement.

FA Liat publi hed ly y i Unserby Lentdon,

175

TAB. CCCXCIX.

PLUMBUM carbono-muriatum.

Carbono-muriate of Lead.

a
—

Class.3. Metals. Ord. ios
-Gen. Tead.n2 Spec. Carbono-muriate.
SyN nae New Variety of Lead Ore. Chenevix in Ni-

teak oie 4to Journal. 4.219. Klaproth’s Ana-
.., __ lyses, vol. 3.

“ ae ne Aa

T pre highly gratified i in the er ci of elucidating this
rare substance, which does not seem to have been known to
be found, excepting in this country in the neighbourhood of
Cromford Level, near Matlock, Derbyshire. It was first
discovered to be anew mineral by the discerning Count de
Bournon, who has a primitive crystal of it, and many excel-
lent sketches and memorandums made from our late good
friend the Hon. Charles Greville’s superb collection, which
is now happily secured to this country in the British Mu-
seum, and from which we have selected the best specimens
for these figures. 7

The crystal is a rectangular prism, whose planes are pa-
rallel to the nucleus, sometimes having a cubical proportion,
with the angles replaced by isosceles triangular planes, the
incidence of which upon the terminal face is 122°. See the
blueish figures on the left of the yellow crystal, which look
like regular cubo-octaédrons. In these the columnar edges
are a little rounded by small faces, which in some crystals
are so much enlarged as almost to obliterate the primitive
ones. The yellowish lengthened crystal has the first of
these faces enlarged so as to form a four-sided pyramid,
with only a minute vestige of the terminal primitive plane,
and the edges of the prism replaced by truncating planes
arger than the portion they leave of the original faces.

This substance has generally a glassy or gem-like lustre,

176

is softer than Carbonate of Lead, which will scratch it, and
with which it has been confounded. It is accompanied by
small crystals of dull purplish Cubic Fluor, nearly in form
of a line above them ; and Galeena or Sulphuret of Lead on
the nght, and which is distinguished by its square appear-
ance. The whole on opaque Sulphate of Barytes, commonly
called Cawk in Derbyshire; and there are some small cry=
stals of Carbonate of Lead scattered about it.

According to Mr. Greville, it was about the year 1785.
that this curious local substance was found; and the works
being discontinued, there are very few specimens known.
The outline or geometrical figure explains the form of the
columnar crystal, and agrees nearly with some other spe-
cimens which terminate with a flat apex.

TAB. CCCC.

Tans figure is taken from another crystal in the same col+
lection as the last. It is a short prism, and shows the pri-*
mitive faces by the parallelism of the conspicuous flaws or
fractures. It-has also two additional faces on the columnar
edges, at 153° 30' with the primitive.

One of the specimens in the same collection has very thin
tabular crystals similarly modified, set edzewise, and form-
ing a group about three quarters of an inch in diameter.

The geometrical figure shows them with a more lengths,
ened column, forming sixteen columnar faces, besides the
eight faces which belong to the octaédron of the whole,
with the two ends being regular, and forming-a polyedron of
26 faces: there are two of the truncated cubical crystals ac-,
companying this.

Analysis by Chenevix. By Klaproth.
Miinatie Acid) &)'9)'.s 2o PO, 1 BAe
Carbonic Acid . 6. witha little water 6-
Oxide ‘of ead 29s Of, FA, OF DERE Base

99 100° 00

Spec. Gray. 60° 651.

i}

fulblldlcd ly fi Teverly Daten.

400.

OO EDEN AR nate ao Eta &

ALPHABETICAL INDEX.

TO

VOL. IV.

Acrtinotire, Brush-like.. .. .. 379

Alluvial depositions, forming soils .. 335

Antimoine sulfurés ..02 <i) he Pe.

Antimonium sulphureum.. .. 365

Antimony, sulphurated .. *«.
Sulpntinet Of! @ shut ay sie 305

Argent natif octacdre ;

Argentum nativum cryst... 3. a. 327

Are ile schisteuse Lue Sk Rese atth 3

———-— Hovaculaire Paes 355

Argilla electrica He) pd een lool. f8.s09

- Topazius ee -- 303
Aspillaccous Slate? 2. 1 hte. 8s 553
Arsiilite Se Rr ARE SONY Vat alu ere ib.
Areillo- Caleta wre cd Wee
Asdnite BP: 3 BES ery RONEN eI
B 3
Barytes sulphata ES IOME WP oper Mal ts te) 0 Mo komipss Ke)P
Sulphateeivos) (sd ns hes 380
toring, pelictiveal a 381,382
Reale Metal orews see a. dee cee
Bismuth, Carbonate of .3 -4. -4. 344

PU TALT AER Ae sca is ng 6 ors)

SDA Vee leds Kigcictite 343
Bitumen, Inspissated | .. ; 301
Bituminous, Séhisiis .. 3. ee
Blend, dodecaédral .. . Sh 3096
Borax gemma nobilis, Topazius oe
Braunspath Sichiy orm, och te'e # tein

C
G@alcareous Schist» .. ./ .. Ete 347

Calcedony, Bony .. .. i.
VOL. ly. P

Page.

149
61
123
ib.
ib.
ib.
45
ibe ,

97
101
53.147,163
117
97
ib.
Al
31

178

@aleedony} (Cttbic. s/s) ia tes
- Octaédral Benes oe
-— Shell-formed..

- Stalactitical .. ..
Calxcarbonata 24) 15, ieisiok sss

—

Cry sts. o ae
dodeeseae,
———_——_——— metastatica
fDTOSAy ateeets
magnesiata = ««
Fluor, var. arenacea
phosphatarey -s2 a5 es
Garbo’ bituminosus .. 62) ..
- vegeto-bituminosus.. ..
Chaux carbonatée analogique ..
———— contractée ..
inerustante
—_—_—— prismatique ..
Chiorite’* Marlesee 0... 2.)
Coal, bituminous,
TEMIANSA? ERE se Mere
—Kimmeridge .. ..
—plantformed .. .. .
Staffordshire
vegetable...

Cobalt, Arseniateof.. .. ..
em SHOWERS (OL clsieeoe. | iis
——.-+ ore, black

—.—- oxide of a :
or - native 2

-- oxydé noir § he
Cobaltum arseniatum ais
oxygenizatum ..
Cockle F x
Conchyliolithus productus
Copper, arseniate of, rotate ..
— hydrate wel ars Sea oe
Moss .. .- 3
native, wire- Whe.
ore, black ..
PLAY. oc weets

——— vitreous a

———- peroxide of . eee
oo Pyrites, Swimming j
= Sunsel phuret of . Be

Sulphate CM ee

containing animal

ALPHABETICAL INDEX.

al:
ste 308
“2 ; 307
ele 310
56 309

-- (317.323.346
347, 360,370
ie 305, 366.316

322
314,315

a 345
ee 321
US 330
os 372
.. [329.385,386
ise 313
324

386

313

A 385
329

313

R 326

: 340
ee 326
: 340
as 303,304
a 302
376

359,360

302

: 301
: 359,360
ee 351

Page.
1Z
il
14
13
25.37 .83.85
129.131
9.10.23
35

ALPHABETICAL INDEX.

‘ab.
Copper, Sulphuret of “ : 301
a ATSenICO= Perit
rous } 358
gray
eV tHIOl Ole: Peet Mei
Cornu-ammonis, Calecdonized ee 310
Gotham Niarbleveawaek Wee sec es 325
Ginivne sultaten ee Peete cea oe
ASCO TEAK iar AU A oh Ay Sede rs
— gris FSWENISIO REDS
Cuprum arseniatum .. .. -. e. 303,304
hyperoxygenizatum .. .. 302
TIALLY) “inevesnerenn, ale 370
—— sulphatum .. .. .. «. 351
— sulphureum.. .. 301
—-——_—_ Satan aren 358,359,360
E
Etain oxydé concretionné,. .. ...
SUN] Aa ae rely a teete neta oeanatiens eke
F
Fahlerz
=e t NORTE SiG icaeaY yall 358
Ferrum oxygenizatum .. 375
QUaLeZOSUMIN So Seas) ele 368
sulphatum ye 350
sulphureum.. .. .. .. (866,367,374
383,384
Flints, Striped .. i eeeitaea 383
G
Galena, ‘Commpacty ys iy ste 8 Feit) oc 392
Slickensides He
Garnet SiS de IRI a Re ie
Trapezoidal .. 373
SV eSuviaiiy macs tea ee 371
Granat, Bdlereaue aioe ce he
Granite 7), 17. ees Enea Mc 332
CGrau-spiess- olanzerz A Bh ONS
Green stone .. He

Grenat granuliforme We Bahome sai
Groner BL ance en UAE! Lia
Gransteimin cs ee ee

107

93
14
AL
03
109
107
5

3
143
98

I
107.109.111

05

107

141

127

gl
125.139.155

162

1890
P Tab
H
Hone-stone .. .. 355
Hornblend seat situs 328
—=--_ common... , she ialice
Hornblende, gemeiner .
Hornstone; Gubie 9) 22) ds. os.
Hyacinthe, var. Da Seaakes Sea Rene
Hydrogen Bitumen .. .. . , 361
I
PAGCTASC Gta enuccute toe 371
Tron, oxide of .. : 375
—— stone, Siliceous .. 368
—— sulphateof ..... .. . 350:
—— sulphuretof .. .. .. «+ |366,367.383
384
K
Killas ae es Se Sete ;
Kimmeridge Coal R : 313
Kupfer glanz SED ALS A oe
schwartze BK A
L
Labrador Stone, Scotch og
Lapis.ollaris .. 348
Lead, Carbonate of in acibel i
mine. 342
— Canoe Pare of ne. 399
Sees , cubic 460
—— Glance, spicular compact
——— Green ores of . ads Rite) revs
Sulphate of HY 341
Lime, Carbonate of .. - |316,317.369
37
Columnar garnet- ;
formed meh data Mares ty: oe 318
cryst.in hexaédral
~ columns oe ae 305,306
Hodes teal: 322
Fibrous oi 345
Incrusting 346
Magnesian, with
Iren .. rs Fey oR eM 321

ALPHABETICAL INDEX.

gl
125.1535

05."
17
109
111

ALPHABETICAL INDEX. ~ 181

Tab. Page. -
Lime, Carbonate of, metastatic ie 314 19
$$ maackled aS Ls 21
Fluate of, arenaceous seditrele 330 51
erat OSD ALe OfMmmrm iia cs aire 372 135
Stoneé;)@oralloid 4). 2... 323 pay!
M
Mica, Brown and black Se Mp eN eee 391 165
Goldene 0k (ma kia ie SO i772
SELMER ah ect a cihine avis EN 304 171
Poulsen che waibrae Wa 336 62
Maytilus-crassugier 8 ewe ayo 386 160
CUMLER EM oy Aen Ns ts 323 37
N
Novaculite ghey, elie!) elie on 355 101
O
DpaliesoHe non me Kenel E mee / 7! 145
Pstcocollawwy ey eh Sees Oe 346 83
P
Beensteimbinee o/s Ua a 103
Fetroglex tesinite Ar. - J... .... |. ib.
Pierre de Thum MNS 15 op rah dam > 31
Patchstone, Glassy ees oe) - 356 103
EORRY LY sin SV yh marnane ; ib,
Steatitic .. eM as B57 105
Plomb sulfuré compacte .. .,.. 167
Plumbum carbonatum .... Ae AS 349, 73
— carbono-muriatum .... .. 399,400 175,176
sulphatum oie ce canny oa 341 7\
> Sul imareaim: 3b. ss. , Ure 392 167
Potstone BE As ee OOTP 348 87
Del stone (0) Nea Oe anaes 88
Pyrites, Cock’s-comb Sees CO 367 126
SERS or Bending. 20). 374 139
S WII oe) Sad are 3011. i
Pyrope SEs Canale a hie 364 121
Q
Quartz agathe Baas ol 11.13
Crystallized e. se oo 318 oF
Bibtouss sorts; Age oe ae 387 161
Radiating or Stellated ..

313 109

,

182

R

Roche Feldspathique.. .. .
Rotten-wood Rock .. .. -

S

Sanarsiliciousie, wie, nae liters
SALES AT Oe Gauisen teh) Oo

Schiller-spath .. ..

Schistus ..

wehorl Curved ss tos. hes
Pointed

White deren ssc ee
Schwarzererdkobolt.. ..

= a ESTaN CLI GL AE Gn

Sienite Bowles omnis
Silex axinimorphum ane 36

LOCTASIS Revie. yvlerei) ere

—— Mica abtHitetwiih tebe iane
piceus ES ANN
quartzum . .

——- arenaceum :
cryss. nh ees

Var. .- es

stellatum .

Talcum

Silver, Crystallized native...

Slate, Clay
—— Common argillaceous A
Slickensides ..
_Snake-stone .. ..
Soils ie. a

Spath Chatoy ant Aa Te ra

Stannum oxygenizatum ..

BLOM Mer ind picl in Geet Niieie
SChist,,Calcareous \ iu.) />a is»
—-- Silicious BONG rah he Naas

Bituminouss4..) avo os)

Transparent lenticulaire
Viole ere etece Maan tele

frAgTIB Ge eye oie! raphy ies
granatum .. ore aon 6S

fibrosum ..
opalinum ..
stalactites .. _

ALPHABETICAL INDEX.

Tab.

364.

.- (391.304,

- 307,308

337,

331

333
320
379
373
371
395
356

.388

362

31
149
-121.137
133
165.171
103
11,12.162
115

27

ALPHABETICAL INDEX.

s

Stannum oxygenizatum fibrosum

sulphuream
Strontia ane ata

Strontian, sulphate of, Brash: like MN
_ radiated
stellated

—

Talc, Massive
—— Ollaire .. ..
Tar, Mineral
——~ Mountain .. ..
Thumerstein, Le ..
Phumerstome {$2.0 2.
Tin, Grain aes
—-— ore, Wood..
—— Oxide of
——$_—— — hexmiatitic
—- Pyrites sé. 66
—-— Shoad.. ae
—- Stone, Fibrous ..
——Stream .. ..
—-Sulphuretof ..
— Wood.. 3
Topaz ee
- occidental” ae
PRO DAZE NY Jerai Hi s'a,0/ 0s
Topfstein ..
Tourmaline, Stellated
- White ..

Vv

Vegetable Coal ..
Vismuthum nativum
Vismutum carbonatum

—___—__-— nativum
Vitriol, Blue ..

Ww

Whet-slate ae
Wismuth, Gediegen. . :

Sate

Tab.
352
339

1. 18115212.310
312
Sylal

311.319

" Foud -
& & »
on P aa m
184 ALPHABETICAL INDEX.
Tab. * . Page.
3S
Yanolithe. ee ae ee os ea ee 3k
i rm Z
Zinc Sulpiate Ob eM Sch ee ase 349 3 8G
Sulphuret of .. .. .. .. [396,397,398 175
Vitriol of.. ee ee ee ae 80
Zincum sulphatama .... s) 2.) 4. + 5340 ib.
——— sulphureum -- ++ «. (396,307,398 173
MiBMess os fish ee eh be ewes 67
CORRIGENDA.
Page. line. ;

12 10 formamillated, read mammillated.

17 2 for Carbon, read Carbo.

22 penult. for pith, read pitch. ‘

$2 ult. for Rashley, read Rashleich.

56 5 & 6 from the Lotiom, for “myself, by favour of Mr. W. Morel, being
detached,” read “my specimen by favour of W. Morel, Esq. was
detached.”

63 12 forsiliceous, read silicious.

69 2 for oxygenatum, read oxygenizatum.
108 1 for tetrahedron, read tetraédron. i
111 6 for hexangular, read hexaédral.

— 25 for sulphuretted, read sulphureted.

118 4&5 from the botiom, dele the parentheses. /
121 12 for dingey, read dingy.

127 3 for siliceous, read silicious.

163 2 for Silex electricus, read Argilla electrica.

_ Printed by Richard Taylor and Co., Shoe Lane, Lendon,,

sa

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ae
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ik. ah i
gt
i, Me

ras

ee ee
lescribed | e@uests até

a

d killed ter
house at
<.2

Ic

has
den,

# A beekeeper in the Bourne district of Lin-
B colushire has had’ many pounds of honey
destroyed by a large swarm of wasps in-

r that ha
tow

2

7

amazement #

pa ce me en Sp A LOT AK
ESSEX. 37% ute be

Ne E ‘he Rat ? Committee reported that, during
p ight tackle held the fish until a Jand- ne last six months, 45,000 rats had been

s Was brought. The pike was landed ® destroyed in that district at a cost to the®

ned the scale at 9Ib. 15oz. | 8 yvatepayers of £190 5s. 2d. i
ads of Thames dace have congre- Brramucrs= :
Ww below Hampton Court Weir for} A fine specimen of a female otter, which was¥
1 Bee Poss, the Tiver.in places bo’ng § recently caught at Acton Town Station, District
yb ck with the shoals. In the foam § Railway, has been preserved, apd is now on view gy

ate to be seen leaping, salmon-like, g on the west-bound platform of Mansion Hous

i efforts to get over the weir, @ Station. BAMA ALS Fo A MAE 25 Be

AN eS cern) nae eS

ON THE UNDERGROUND. | SWIMMERS ATTACKED BY EELS.

: WS. 4 94 re
§ workmen were e i oe & are A mahi:
rk re Beet tee es | Writing in the “Safmon ue Trouth

at Acton Town Station th Dane
Railway, this Gerad tio & Magazine,”’ Colonel R. F. Meysey-Thompson
. a@ manhole an otter, 3ft, Gin. in & Sives.an instance of swimmers being at-
Brom head to tail. 7 * gi tacked by eels, with fatal results.
me brought it to the surface, but the @.. Many cases of bathers being drowned ec-
lied shortly afterwards. ‘ curred in a rapidly flowing river near an out-
ought that its death may ha #
f eae Shock, s the pee pave pee of Colonel Meysey-Thompson. ‘Aft
= across the metals, g time it was found that the fatalities were
oa easmerivmecwsesrte Aue to the swimmers being seized by eels—
ELEPH | NP AP PHE 3 Which attain an immense size in those waters
j rh ee “a pete mond eee Tenet the Sree of the
Af-— - Ne »|water. The bodies when recovered were in- 4%
addition, to the toneee Yoo-\Vatiably found to be partly eaten by eels. Pea
ae ons Is #, (SBReCuTOn of the rare fy A Sutton on-sea (Liticulnsnire correspon« a
bap trora the Crozet Islands, in dont writes stating that while two members f¥
pearctic. Ocean. li was presented to. of the local volt club were playing on the Ra
Pr. Louis Peringiey, directory links a hawk swooped down and few away
i fricau Museum, Cape ‘Town. with one of the balls in its aoe
Oe ; Ft one. ee a TTS aS cee See
he cade now vereing on ex Several thousands of lampreys have been
. _° caught in the Thames near Molesey aud Ted-
Ry dington in the last few days. #*a :
SAIS SEE STE EEE
‘over ‘T1b. has been cap

A pike weighing a
Hiured on a reach rs Teepe re
angicr. 2, sl 9 rae

See ae

arom my head and used its
n extent as to make the¥

ee ye
OW NORPOLK. fi ee

2 DAILY BATHE IN THE SEA—A hare

“y Bgiad made a daily practice of swim-

m tbe seo at Cley, to the delight o

% has been captured by some loca
‘in — boat. ‘Uhey chased. thes
seaward for 300 yards before they Se

“™p with it. |The hare was then ex

rand was easily captured. Shes

AT GRAVESEND.

xcitement prevailed at Gravesend yester-
400n Owing to the presence of a seal j
ee anal, which had come up the Thame
Diy with the morning tide.
Medes), which was a fine specimen, first made
Mmeecanal lock, but afterwards escaped to
Canal, wkere it was hunted by a large

der given, that it. was to be left

mcone shot.at it, wounding it in the

. oats OS reheat > eal ae yin EF Ee a ST ee a, ee a ae i me a pen 0 Ge , a ON AES OO, ceete 5
Og EO age cg SO SGI EO | Se ee eRe ae re DR SG a ha? £ ee e Pela grr - i —
- si Sa ted . - ” . es og, anne

. 2 2 eo 2 2 a)