Earths, MINER 
rocks of gneifs and micaceous fchiftus. It is called moon- 
fume frornits colour and foft luftre. Specific gravity, s' 559 - 
Contains filex 64, alumine 20, potalh 14, lime 2. Vau- 
quelin. 
5. Felfpatum fibrofum, or fibrous felfpar: fibrous, 
with the fibres parallel and in diftinct layers. Found 
fcatteredly in Bohemia, with frequently the veftiges of 
quartz or mica. Colour ufually brown, Ihining inter¬ 
nally like mother-of-pearl; breaking into indeterminate 
fragments, and is harder than rock-cryftal. 
6. Felfpatum oculus cati, or cat’s eye : diaphanous, of 
an imperfeffly-foliated texture, exhibiting parallel fibres 
internally, breaking into iomewhat-irregular fragments. 
Found in Ceylon and Siberia, of a nearly-fquare figure, 
with fharp edges and a good deal of brilliancy. Colour 
grey, with a tinge of green, yellow, or white; in certain 
poiitions reflecting a fplendid white like the eye oi a cat; 
fometimes brown with a yellow or red tinge. Its texture 
is fo compadt, that the foliations are hardly difcernible, 
and is fo hard as to ftrike fire with flee!. , Specific gravity, 
2-66. Contains filex 94-50, alumine 2, line 1-5, oxyd of 
iron C25. Klaproth. 
Circonius, Zircon, or Jargon.—Confifting of filex, a 
more than double proportion of circonia, and a very linall 
quantity of metallic oxyd, partly of iron, partly of nickel; 
very hard, ponderous, imitating the diamond in its luftre, 
f iarafitical, foliated with the foliations incurved, cryllal- 
ized ; not fufible per fe. 
Circonius Zeylanicus, called alfo mock diamond, is the 
only lpecies. P’ound in Ceylon, in fmall irregular grains, 
or cryftallized in four-fided redfangularprifms terminated 
each fide by a four-fided pyramid, or in double four-fided 
pyramids. Colour grey, greenilh, yellowilh-brown, red- 
dilh-brown, or violet; ftrongly femitranfparent, fometimes 
opake 5 fcratches glafs, and is not altered by the heat in 
which the diamond is confumed. Specific gravity, 4-416. 
Contains circonia 68, filex 31*5, nickel and iron 0-5. This 
earth is found in one other lubftance only, viz. the hya¬ 
cinth : fee p. 459. 
Amarus, Bitter Earth.—Confifting of filex, a fmaller 
proportion of magnefia, a very fmall quantity of alumine 
and carbonat of lime, and 10 per cent, of oxyd iron ; hard, 
tenacious, fubopake, a little greafy, green, of a fplintery 
texture, breaking into indeterminate fragments, of a 
common form ; not fufible per fe. 
Amarus Amazonicus, the only fpecies, is found in the 
Eaft, New Zealand, and the Helvetic and Subaudic Moun¬ 
tains, fometimes detached, fometimes forming vaftmafles. 
Colour green with a call of blue, and in the prominent 
point of the fragments inclining to milk-white. By the 
inhabitants of the Eaft: and New Zealand it is fafliioned 
into various ornaments, veflels, and arms. 
Chlorogranatus, Green Earth.—Confifting of filex, 
a large proportion of oxyd of iron and carbonat of lime,- 
with frequently alumine ; hard, never opake, cryftallized j 
eafily fufible in the fire. There are two fpecies. 
1. Chlorogranatus verus, or true green earth: green, 
becoming honey-yellow in a white heat. This occurs in 
double eight-fided pyramids, augmented at each point by 
another three-fided pyramid 5 but fometimes in fix-fided 
prilms, terminating each fide in a three-fided pyramid. 
Both varieties are found in Bohemia and Franconia. Co¬ 
lour from leek to olive-green, fometimes diaphanous, 
fometimes pellucid, and often forms entire ftrata with 
layers of clay; frequently contains a fourth part of 
iron, and is ufed as a flux in iron furnaces. Specific gra¬ 
vity, 375 - 
2. Chlorogranatus dubius : red, cubic. This doubtful 
fpecies contains about a fifth part of carbonat of lime im¬ 
pregnated with carbonic acid gas, and about a tenth part 
of iron ; cryftals fmall, aggregate, feated on friable fand- 
ftones. May probably, not belong to this genus. 
Arena, Sand.—Generic characters: confifting of com¬ 
minuted iiliceous ftones j rough, hard, dry, in minute dif- 
ALOG Y. Earths. 4G3 
tindi granulations, not penetrable by water; not fufible 
per le, but melting with lbda into glafs. There are eight 
fpecies in two divifions. 
I. Originating from comminuted flint-ftones. 1. Arena 
filicea, or filiceous fand : compofed of fragments of flint. 
The only fpecies in this divifion. It is found in Buck- 
inghamlhire and other places. 
II. Compofed of comminuted quartz. 2. Arena labu- 
lum, or gravel: confifting of angular unequal large grains. 
Found every-where on barren rocky mountains, and is 
produced by granite which has mouldered from expofure 
to the air. It is frequently found mixed with particles 
of mica, felfpar, and argil. 
3. Arena micacea, or writing-fand : Ihining with nu¬ 
merous interfperfed fmall fcales of mica, refembling thin 
plates of gold or iilver in colour and luftre. Found in 
Sweden and Germany, and in the ifland of Caflerita; and 
is compofed of comminuted granite, and other like ftones. 
It is the fand ufed to dry up the ink on newly-written 
letters. 
4. Arena ruftica, or common fand: confifting of round- 
ifh unequal grains. Found every wherein Europe, prin¬ 
cipally upon fhores; and contains fome lamellar particles, 
apparently of quartz. 
* 5. Arena colorata, or yellow fand: in roundifli minute 
femitranfparent grains, tinged with oxyd of iron. Found 
in South America and Europe, principally on the fliores- 
of lakes. Colour yellow, yellowilh, or teftaceous, rarely 
red, violet in the Baltic near Germany. 
6. Arena glarea, duft-fand, or grit: in very minute- 
grains, mixed with pulverifed alumine. Found on bar¬ 
ren commons and heaths : is very eafily blown about 
when, dry ; but when wet is rather plaftic, and yields to- 
.the preflure of the hand. It is chiefly ufed in the beds 
and moulds where metals are eaft. 
7. Arena horaria, or hour-glafs fand : in. large equal* 
round tranfparent whitifh grains. Found on barren: 
heaths and woody commons ; and is principally ufed in- 
hour-glafles. 
8. Arena mobilis, or quick-fand : in very minute round 
tranfparent white grains. Found in the fea and adjacent 
waftes, and is alfo thrown out from fprings ; when dry, it 
is fo light as to be driven about by the winds and col- 
iedted into fand-banks; and often taken up in vaft mafles- 
by whirlwinds, overwhelming and fuft’oeating travellers, 
and even whole villages. It is kept compadt by the roots 
of the Elymus arenarius, Arundo arenarius, Triticum 
repens, and fome fpecies of willow. 
Chalcedonius. —Confifting of filex, a fmall quantity 
of alumine, with fometimes about a tenth of lime, and a 
flight trace of oxyd of iron ; hard, lightifh. Alining within, 
breaking into indeterminate fragments with fharp edges, 
compadt, not mouldering in the air, of a more or lefsi 
perfedtly conchoidal texture, never opake, tough, admit¬ 
ting a high polifh, and generally of a common form j not- 
melting before the blowpipe. There are feventeen fpecies.. 
1. Chalcedonius cacholonius, white chalcedony, or 
cacholony : milk-white, fomewhat diaphanous, becoming 
opake in the fire. Found in the rivers of Buchareft and 
Mongool, and the Feroe Iflands, where it lies between 
the ftrata of femi-tranfparent chalcedony. It is never 
found in drops or ftaladfitical. The Calmucs make their 
idols and domeftic veflels of it. 
2. Chalcedonius genuinus, or true chalcedony : grey, 
of a flat texture and common form, not filling fponta- 
neoufly into fragments. The name Chalcedony is de¬ 
rived from Chalcedon in Bithynia, the place where it is 
faid to have been originally found. It is met with alio in 
Cornwall, and the iflands of Scotland ; in Iceland, Silefia,, 
the Feroe Iflands, Saxony, and Siberia, in various fliapes, 
kidney-fliaped, ftaladfitical, globular, botryoidal, like hol¬ 
low pebbles, often containing air-bubbles, or drops of wa¬ 
ter j alfo in angular pieces and veins in porphyry and. 
amygdalite, and fometimes cubic. Colour various lhades 
of grey, with fometimes a tinge of-green or blue ; luftre 
generally 
a 
