EARTHS. ADAMANTINE. 58. Adamantinus. 175 
ORDER VI. ADAMANTINE. 
(Jonftjling principally of corunda or adamantine earth. 
58. ADAMANTINUS. Confifting of adamantine 
cartli, the greater part alumina, a little filica and 
iron: very hard, ponderous, lamellar with ftraight 
foliations interfeding each other in a 3 -fold man- 
ner, breaking into rhomboidai fragments : per- 
fedly apyrous, and yielding a little to the file. 
Corundum. AdAMANTINUS. 
Corunda. Klaproth. Chetn, ar.nal. 1789. i. 7. 
Adamantine earth. Kir^wan mineral, i. p. 17. 
Adamantine fpar. Schmeijer miner, 1. p. 57. 
Diamond fpar. Jamei/on miner, i. p. 93, 
imperfeft Corundum, Ihomfon chem. 3. p, 507. 
Found in China, Bombay, France, and Spain, in granite ; colour 
grey, with often various (hades of green, blue and brown; 
lullre tranfparent, and when polilhcd (hines like mother of 
pearl : is fometimes found maffive, but moft commonly in 6- 
ficed prifms, and fimplc acute 6-fided truncated pyramids ; 
it is ufed like diamond powder for cutting and polilhinghard. 
minerals; fpecific gravity 3,981. contains corunda and alu- 
mina 84,00. fihca 6,50. oxyde of iron 7,50. Klaproth. 
