EARTHS. PONDEROUS. 7. Croffopetra. 73 
1. Of a common amorphous figure. 
2. Cryftallizcd in numerous forms and variations, the moll ufual 
of which arc the c^uadrangulaf and hexanguiar prilms, the 
double quadrangular pyramid, the quadrangular table be- 
villcd at the edges, the 8 Tided plate, and the fmall rhomb 
with obtufe angles ol 105°. 
Cryllallized fulphate of Barytes. Soiverij Br. min. i. 70-1-2, 
Barofslenite. K.ru an mineral l,;l. 136. 
Sul phat of Barytes, 7 homfon s them. ^ p.(>zi. 
Common ponderous Spar, or Cawk. ^chmeiff^ min, l. 257* 
Found in various parts ot Britain and Europe, and is the moll 
common matrix ot metallic ores; it is lometimes found in 
powder, often in amorphous maffis, often cryllallizcd : it is 
lometimes highly polilhed, generally diaphanous, and in its 
cryllallized tla e tranfparent and refleaive: colour Ihowy, 
filvery or blueifli, greyilli, greenilh, r'eddilh or yellowifh- 
white, often flclh colour, finoke colour, honey-colour, vina- 
ceous, rarely olive-green, or grcei.ilh or yellowifli-grey, or 
greyilli-black, very rarely blue: the layers are generally 
Itraight, fometimes incurved ; the primitive form of its cryf- 
tals, according to Hauy, is a redlangular prifm, whofe bafes 
are rhombs, with angles of 101 deg. 30. and 78 deg. ^o, 
fpecific gravity 4+30. contains by ahalyfis, pure barytes 
67,2. luiphuric acid 32,8. Withering. 
^’’llatitia. Of a rounded form, or coating other bodies. 
Found on Mount Iherg in Hercynia, of a llalaflitical origin and 
form, in other refpedls agreeing with Barytes vulgaris. 
7. CROSSOPETR \. Confifting of ponderous 
earth, a larger portion of filica, and a iinaller 
of aluT.ina: lightilh, hard, parafitic, meagre, 
cryftalhne: not totally loluble in fulphuric acid, 
even in a boiling hear, melcmg with difficulty in 
the fire. 
"0'1/fa. ^ j'jjgj redangular tables or pi ifms, tranfverfely ftriate, 
terminating at one end in a needle point ; two of them 
culling each other crofswife and longitudinally. 
Heyer them. annaU 1789. 1. p. 212. 
Found upon caicare lUS Ipar, in the mines of Hercynia, near 
Andre :Jburg, in Imallcr aggregate ctyllais, fometimes very 
minute, rarely pellucia, oftener diaphanous or opake; co- 
lour milk-white, hyali e, yeilowilh, not always ftriking fire 
with Heel, yet frequently making a mark upon glafs : melts 
with borax and foua, with ebullition, 
VOL Vll. _ K 
