Earths. M I N E R A L O G Y. Earths. 
450 
rhombic, lamellar with ftraight parallel foliations, break¬ 
ing into rhomboidal fragments. Found in Germany and 
Spain, with the cryftals generally in fix-fided prilins, ter¬ 
minated by two-fided or four-fided iummits : it common¬ 
ly caufes double refraction: colour white or grey. 
12. Gypfum teflulare, or teflelated gypfum : pellucid, 
white, ftiining, lamellar, with ftraight foliations, breaking 
•into rhomboidal fragments, cubic, a. With two angles 
truncate. £. With four angles truncate. Found in va¬ 
rious parts of Germany. 
13. Gypfum tetrahedrum, or four-fided gypfum: pel¬ 
lucid, white, Ihining, in four-fided prilins, breaking into 
rhomboidal fragments, lamellar with ftraight foliations. 
Found capillary, near Freyenwalde, in the middle mark 
of Brandenburg. 
14- Gypfum prifmaticum, or prifmatic gypfum : pel¬ 
lucid, white, fiiining, in fix-fided prilins, breaking into 
rhomboidal fragments, lamellar with ftraight foliations. 
Found in Germany, Auftria, SwiiTerland, Saxony, and 
various other parts of Europe, generally accompanying 
the G. giacialis and fpecularis. The cryftals large or mo¬ 
derate, fometimes capillary, often with two of the faces 
fimooth and the reft of the prifm longitudinally ftriate, 
fometimes in pairs, or aggregate in a ftellate manner. 
15. Gypfum pyramidale, or pyramidal gyplum : white, 
ftiining, pellucid, breaking into rhomboidal fragments, 
in three-fided pyramids, lamellar with ftraight foliations. 
Found in the canals through which the fait waters of the 
lakes of Upper Auftria have been conducted. 
16. Gypfum lenticulare, or lenticular gypfum : white, 
fiiining, pellucid, breaking into rhomboidal fragments. 
Found near Sangerftiaufen, in Thuringia, near the Hartz- 
foreft, either folitary, or concreted into parallel or hemif- 
pherical clutters. 
17. Gypfum globofum, or globular gypfum : meagre 
and dry, breaking into indeterminate fragments, globular. 
Found near Balobania and Schemnitz in Hungary; white 
or brown, opake or diaphanous ; the globules fometimes 
folid, fometimes hollow, fometimes filled with cryftallized 
gypfum. 
18. Gypfum ftillatitium, or ftataCtical gypfum : preci- 
itated by water, meagre,lamellar with ftraight foliations, 
reaking into indeterminate fragments, with the frag¬ 
ments into which it fpontaneoufiy falls coated. Colour 
white or grey, rarely yellow'. There are four varieties. 
«. Of a common form. Found in Sweden. 
Of a conic form. In Sicily. 
y. Of a branched form. In the fides of fait lakes. 
o. Of an undulate form. e. Of a vermicular form. 
Thefe two laft varieties are found in falt-petre. 
Hepaticxjs.— Confifting of carbonat of lime, barytes, 
fulphuric acid, and inflammable matter ; loft, lamellar ; 
of a common form, either fpontaneoufiy or when rubbed 
giving out an odour like liver of fulphur, not effervefcing 
w ith acids ; crumbling to powder in a fmall degree of 
heat, which forms a pafte with water, and hardens in the 
air. There are three fpecies. 
1. Hepaticus folidus, or folid hepatic earth : compafif, 
breaking into indeterminate fragments, receiving a polilh. 
Found in the province of Mansfield in Weftphalia. 
2. Hepaticus fquamofus, or fcaly hepatic earth : opake, 
Alining internally, of very minute fcattered foliations, 
breaking into indeterminate fragments. Found at Conif- 
burg in Norway, at Andrarum in Scania, and in Bohemia. 
Colour blackilh-brown, brown, yellowifh, or yellowifh- 
white. 
3. Hepaticus fpatofus, or fparry liver-earth : Ihining, 
diaphanous, fmoke-colour, breaking into rhomboidal 
fragments, lamellar with ftraight foliations. Found in 
Norway and Bohemia, and fometimes emits a bituminous 
fmell without being rubbed. Colour white or black. 
Fluor.— Confifting of carbonat of lime and fluoric 
acid; fomewhat ponderous, parafitical, never hard, Ihining 
in the dark, and crackling when .heated to the degree of 
boiling water; not effervefcing with acids, but, if diftilled 
with the mineral acids, emitting the fluoric acid gas, 
which has the property of diftolving glafs; melting be¬ 
fore the blow-pipe into a tranfparent glafs. There are 
feven fpecies. 
1. Fluor pulverulentus, fandy, or earthy fluor : whitifti, 
without luftre, powdery, with the larger particles not co¬ 
hering. Found at Kabola Poiana, in the diftridl of Mar- 
maros, in Hungary, between two beds of quartz. Colour 
light grey, greenifli-white, or bluifli-green. When ftrewed 
on an iron plate heated a little below rednefs, it diffufes a 
blue or pale yellow pholphorefeent light; feels harfii, and 
ftains a little. Contains lime 21, alumine 15, filex 31, 
fluoric acid 28, phofphoric acid 1, muriatic acid 1, oxyd 
of iron 1, water 1. 
2. Fluor compaftus, folid or compact fluor: hardilh, 
compafr, of an even texture, diaphanous, brittle, break¬ 
ing into indeterminate fegments, of a common form. 
Found in Britain, and near Stollberg and Straftmrg; 
whitifti-grey, more or lefs pafling into green, often fpotted ; 
frafture even or conchoidal. Specific gravity, from 3-120 
to 3*165. 
3. Fluor fpatofus, fpariy fluor, or fluor-fpar : hardiflt, 
fiiining, brittle, of a common form, breaking into py¬ 
ramidal fragments, lamellar. Found in Britain, Nor¬ 
way, Sweden, Spain, and Germany. White fmoke-co¬ 
lour, green, violet, purple, rofy, honey-colour, or varied 
with lpots, blotches, or veins, femipellucid, or tranfparent; 
breaking into three-fided, rarely four-fided, fragments. 
Takes a fine polilh, and is manufactured into various 
vafes and figures. Contains carbonat of lime 75, fluoric 
acid 16, water 27. 
FI. fpatofus granularis, or granular fparry fluor: 
with the fragments, into which it falls fpontaneoufiy, re- 
fembling very minute granulations. 
4. Fluor tabularis, or tabular fluor: in rhombic ob¬ 
long tables. Found in Swiflerland, Alface, and Saxony. 
5. Fluor cubicus, cubic fluor, or Derbylhire lpar: 
hardilh, fiiining, fmooth, lamellar, brittle, breaking into 
pyramidal fragments, cubic, of various forms. Found in 
Derbyfliire and Northumberland, Spain, France, Saxony, 
Germany, See. of the fame variety in colours as FI. fpatofus; 
moft frequently pellucid, rarely opake. The cryftals folid 
or hollow, or containing a fmall drop of water or fome 
foflile, and placed in a decuflate manner, laterally, or ir¬ 
regular, or aggregate in a kidney or imperfect globular 
form. 
Fluor, or fluat of lime, is rarely of an earthy texture : 
it is moft frequently cryftallized in cubes, as in this fpecies, 
and is remarkable for the natural beauty and variety of 
its colours ; whence fluors have been occafionally called 
mock gems. The primitive form of fluat of lime is 
eafily obtained by mechanical divifion ; but does not often 
occur in nature. It is found principally in veins, either 
Ample or mixed ; and accompanies various metallic ores. 
There is a lpecimen in the Oxford Colleftion, the form 
of which is that of bivalve (hell, to the inner furface of 
which are attached imperfect cryftals of nearly colourlefs 
fluor. This fpecimen had been claffed as a carbonat of 
lime, from which fubltance it is lcarcely diftinguifliable 
by the naked eye. 
Many of the cryftals of Derbyfliire fluor are colourlefs, 
and have their furfaces fprinkled over with minute parti¬ 
cles of pyrites. In fome inltances it appears, that, after 
thefe pyritical particles have been depolited, an augmen¬ 
tation of the cryftal of fluor has taken place ; fo that the 
fpangled furface of the inner cryftal may be viewed through 
the luperincumbent lamime of the outer. In a few in- 
ftances this procefs has been repeated feveral times; and, 
by means of the interpoled particles of pyrites, numerous 
parallel planes may be feen within the body of the cryftal. 
The blue Jiuor of Derbyfliire is found in a mine near 
Caftleton. The mine is in a hill of limeftone, the fub- 
llance of which is broken into irregular cavities. Some 
of thefe cavities contain large ftala&itic concretions of 
carbonat 
