EARTHS. SILICEOUS. 43. Olivimis, 
149 
43. OLIVINUS. Confifting of the greater part 
filica, and a fmaller proportion of aluir.ina and 
oxyde of iron; found in bafaltes, fliining inter- 
nally, generally of a common form, hard, 
mouldering in the air : melting with difficulty. 
Tinged, ' tiiaphanous, of a conchaceons texture, breaking 
into indeterminate fragments. 
OHvin. Werver Bergm-Joum. 1790. 7. p. 5;. 
Olivin. Klr^anznin.'l. p. 265. SchmeilJer \. p. 73. 
Olive Chryfolite, Olivine. Thom/on chem. 3./. 592. 
Found in Arthur’s feat near Edinburg, in France, Germany, and 
moft parts of Europe, imbedded in Bafalts, fonietimes in me 
form of grains, fometimes in large pieces : colour olive or 
yellowilh-green, and when withered brpwnifh or ochr.c- 
yellow: is attacked by digertion in nitric acid, and its ferru- 
ginous parts taken up: fpecific gravity from 2,960. to 3,225. 
’^'treus. Pellucid, pure white, of a glaffy texture; breaking into 
indeterminate fragments, with the furfapes fpheri- 
cally convex. 
Hyalite, Mullers glafs. Kirnvan mineral, l. p. 
Hyalite. Thom/on chem. 'i. p. ^b'^. 
Found in Germany, Hannonier. and Franefort, in rocks of trap 
or ferpentine, and occurs in the form of grains, filaments or 
rhomboidal mafies : texture foliated: fraflure inclining to 
rhomboidal: is generally tranfparent, fometimes, though 
feldom, opake: is ipfufible at 150° of Wedgewood, but 
yields to Soda: fpecific gravity 2,1 10. contains filica 57. 
alumina l8: lime 15 : and a very little iron. Link. 
IMtoiuu Diaphanous, white, of a foliated texture, breaking into 
rhomboidal fragpients, 
Feldipat. Nofe Orogr. Brief, t.p.224. 
Found in Goettingen in Bafalt, and on mount Mendsnburg on 
■ x.'ae Rhine-, relembles Fcldfpar, but is harder, and much 
more difficult of fufion. 
■fi^osus. Diaphanous, white, fibrous, hard, fhining. 
y. H. Miner. Beob. Bafalt. c. Rhein, p. in. 
Found on the banks of the Rhine, near Unkal, imbedded ii^ 
bafalt, and is very brittle* 
