EARTHS. SILICEOUS. 56. Chalcedonhis. 173 



stillautius. Precipitated from water highly charged with its par- 

 ticles. 



1. Inclofing or incrufting Lichens and other vegetable fuhflances. 



2. Incloiing or incrulVmg cryftals, and hence having the appear- 



ance of cryftals. 



3. In knotty hollow kidney-form or botryoidal globular pieces. 



4. In folid or hollow cylinders. 



Found in the Feroe ijlanasx Iceland^ Bohemia, Saxony, and many 

 otner parts of the continent : texture fometimcs approaching 

 to the fibrous. 



tryttallinus* Blueifh, in the form of 6-rided divergent prifms. 



Fuhtel 'von Karpath. p. 1.38. 



Found in a valley near Tatarefcbol in Tran/ylvaniay imbedded 

 in yellow Jafper, 



(vindis. Green, femitranrparent, of a flatter texture. 



Found, though rarely, in the Feroe ijlaiids: colour generally 

 grafs-green, though lomctimes approaching to the aeruginous. 



Chrysopra- Green, with hardly any internal luftre, femiiranfparcnt, 

 lus, of a flatter texture. 



Nitrum fluor. Syfi, nat. xii. 3./. 85. n. 3. g. 



Achates prafius. Wallfyst. 1. ^."262. 



Chrvfoprrffium. Kir-iv an miner, i. p. 283. 



Chryfopras. Jafneif. min. i. p. 191. 



Chryfoprafe. Ihomfon chem. 3. /». 51 8. SchmeiJJer \. p. 113. 



Found in Germany, patticularly near Koferr.ui^ in Silefia, m 

 Bohemia and VVedphalta, generally in foiid mail p, fometimes 

 in loofe pebbles, or layers of afbell, talc, lithomarg. and iron 

 ochre ; internally it is dull ; is hard, but docs not (Irike fire 

 with fteel : colour various fhades of apple-greeu, rarely grafs, 

 leek or olive-green, very rarely greenifli-grey or marked with 

 brown fpots: in a heat of i 30° of wedgevvood it whitens and 

 becomes opake, but does not melt bufore the blowpipe : 

 fpecific gravity 3,250. contains filica g6,i6. oxyde of nickel 

 ijOG. lime 0,83. alumina 0,08. oxyde of iron 0,8. Klnproth, 



lleliotropi" Diaphanous, of a conchoidal texture, green marked with 

 ^Si opake blood- red dots and drops. 



JafpisHeliotropius. Wall.fyfi. i. p. 300, n. 2. g. 



Heliotrop, Blood- ftone, Hchmeij^er mineral, 1.^.116, 



Heliotropium. Kir^wan mineral. l./>. 314. 



Heliotrope, Jameif. i,/>. 187, T horn fon chem. i,;). 531, 



Found in Afia, Per /la, Siberia, Iceland, Bohemia, ?.nd Franconia^ 

 in rocks of trap: colour various (hades of green, fometimes 

 marked with ochraceous fpots or lines: texture more or lefs 

 perfectly conchoidal : fpecific gravity from 2,620. to 2.700. 



