C ] 



a a. Chrysoprase, of a green, or greenifli white 

 colour ; found in folid mafies, and breaks with 

 an even furface, having a dull appearance ; does 

 not ftrike fire with fteel. Anal. Silex 0,96. 

 Oxyde of Nickel 0,01. Lime 0,0083. Argill 

 0,0083. Oxyde of iron 0,0083. Klaproth. 



b b. Hyalite, amorphous, lamellar, compact, 

 colour pure white, fraclure^ even, lameilated, 

 fometimes conchoidal. Anal. 57. Argill 18. 

 Lime 1 5. And a very little iron. Link. 



c c. Opal) Semi-opal, hard and femi-tranfpa- 

 rent ; reflects the light in various hues; found of 

 a milk white, bluifh white and greenifli colour, 

 rarely purple ; takes a fine polifh, but is not fo 

 hard as to ftrike fire with fteel. Anal. Silex 

 98,75. Argill 0,01. Oxyde of iron 0,01. Klap- 

 roth. Of this clafs are Hydrophanes, which be- 

 come tranfparent by placing them in water. 



d d. Pitchstone, cryftallized in hexahedral 

 prifms with trihedral pyramids ; it's various co- 

 lours are white, yellow, brown, greenifli, feldom 

 tranfparent; fcratches glafs. Anal. Silex 73. 

 Argill 18. Iron 00,58. Wiegleb. 



e e. Cats-eye, amorphous, compact, colour 

 greyifli white, yellowifh oY reddifh brown, or 

 ftriped with thefe colours, particularly when po- 

 lifhed. Found in blunt or rounded fragments, 

 and comes from Ceylon. 



f f. Flint, ftrikes fire with fteel, generally of a 



yellowifh 



