EARTHS. SILICEOUS. 52. Lydius, 159 



52. LYDIUS. Confiding of filica, a fmall quan- 

 tity of lime, magnefia, oxyde of iron and in- 

 flammable matter : hard, lightifli, opake, com- 

 pa6t, cinereous, black or greenifh- black, (laty, 

 of a common form, breaking into indeterminate 

 fragments, detached or conftituting mountains: 

 not fufible per fe. 



siliceus, Subopake, of a fplintery fradlure, without interaal 

 luftre. 



Silex rupellris. Syst. nat, xii. 3. /. 71. ». 15 ? 

 Jafpis unicolor nigra. Wull./vji. i. p. 299. ». I. g. 

 Siliceous Shiftus, Kirix an, miner, i. p. 3o6» 

 Siliceous Shiftus. Schmeifser miner, i. p.izy, 

 Keifelfcheifer. Thomfonchem, 3. ^, 577. 



Found in various parts of Europe., in blocks and amorphoas 

 mafles of various fizes, and very often in the beds of rivers; 

 colour blackiih-grey or greenifh, often interfered with veins 

 of grey quartz or blood-red iron-ftone : ipeci£c gravity 

 from 2,596. to 2,641. contains filica 75,00. lime 10,00. 

 magnefia 4,18. iron 3,54. inflammable matter 5,02. 

 Weigleb. 



genuinuty Of an even texture, fometimes approaching to the con- 



choidal, fhining a little internally. 



Bafanite, Lydian Hone. Kir^ an mineral. i./>. 307, 

 Touchllone. Schmeifser mineral. I. /». 128. 

 Lydian ftone. Thomfon chem. 3. p, 578. 



Found in the river Tmolus in Lydia^ and in various parts of 

 Europe ^ detached or in mafles, and is commonly interfered 

 by veins of quartz : colour dark greyifh-black; its powder 

 black : fpecific gravity 2,596. It is ufed as a touchitone to 

 judge of the purity of metals. 



