EARTHS. SILICEOUS. 48. Lazuluf- 
156 
porcellana. Hard, rifty internally, of an in-'perfedtly conchoidal frac- 
ture inclining to the even. 
Porcellanlte. Ktrvjan mineral, i . p. 
Porcelane Jafper. Schmeijfer mineral, x.p.iz^., 
Porcelane Jafper. Ihomfin chem. 3. p. 533. 
Found in large cotnpatt layers, and frequently between the 
fiffures of Bafaltes, in Bohemia and Saxony : has an arid ap- 
pearance when broken, like dried cla\ , and is full of .jraclt' 
or flits; and is fuppofed to have been altered by the adtion ol 
fire : fpecific gravity e,33o. contains lilica 60,75 . alumif* 
27,25. magnefia 3,00. oxyde of iron 2,50. potafs 3.6c. 
Rcfe. 
'Vulgaris, Hardifli, fhining or poliihed imemully, of one unifori!’ 
colour or veined or fpotted. 
Jafpis. Croitli. mineral. fcS. 63. 65. 
Common Jafper. Kirivan mineral, i. /. 310. 
Common Jafper. Sebmeifser miner. \. p.\ 26. 
Common Jafper. Tkomfon chem. 3. p. 535. 
1, Of one uniform colour. 
Silex Jafpis. Sist. nat. xii. 3. p. 71. tj. 1 3, 14. 
Jafpis partic, fublililT. Wall.fyjl. 1. p. 297. n. l. 
2. Variegated. 
Jafpis partic, fubtililT. Wall. fiji. \.p. 299. n. z. 
Found in Germany, Saxony, Sile/sa, Hungary, &c, in larg® 
compaft niafles, fometimes coarfely interfperfed in alternate 
layers with other Hones, and often in obtufe angular pieces! 
colours different lhades of black, white, yellow, red, brow!’’ 
and green, often variegated, fpotted or veined with fevei^* 
colours : is frequently enriched with iron and gold ores> 
and admits a fine polifh : fradlure conchoidal, or fometintf* 
iroperfeftly foliated; fpecific gravity from 2,530. 102,700. 
48. LAZULUS. Confifting of filica, with a 
proportion of alumina and carbonate of lim^j 
and a fmall quantity of fulphate of lime 
oxyde of iron: opake, hardifli, blue, denfo 
without internal luflre, breaking into indeteriTii' 
nate fragments, producing a white powder whe^ 
pounded: neither lofing its colour nor efFcrvc’i'' 
cing from acids fprinkled on it, melting eafily 
the fire into a frothy flag. 
Lazulus. 
Cuprum Lazuli. Syrt, Bar. xii, 3./. 145. «. 12, 
}ri(ntalis^ 
