PETZITE. 

 " Grind with strong arms, the pond'rous quartz 

 betwixt, 

 The soft kaolin with petuntze mix'd." 



Petzite, Haidinger; or Telluegold- 

 siLBER. A variety of Telluric Silver 

 (Hessite), in which part of the silver is re- 

 placed by gold. S.G. 8-72 to 8-83. 

 Analysis, from Nagyag, by Fetz ; 



Silver 46-76 



Tellurium .... 34-98 



Gold 18-26 



Iron, lead, sulphur . . traces 



100-00 

 Brit. Mus., Case 3. 

 PFEiFENSTEm. See Pipestone. 

 Phacolite, Breithaupt. A variety of 

 Chabasite. 



Camp. Ca3 sis + 2^1 Si^ + lOH. 



Analysis, from Leipa, b}'' Anderson : 



Silica 45-63 



Alumina .... 19*48 

 Peroxide of iron . . .0-43 



Lime 13-30 



Soda 1-68 



Potash 1-31 



Magnesia .... 0-14 

 Water 17-98 



99-95 



Fig. 326. 



Localities. — Irish. Giant's Causeway, 

 and Castle Rocks, Magilligan, Derry, fig. 

 326, in translucent to opaque, greyish- 

 white or pinkish crystals, in cavities of 

 amygdaloidal greenstone. — Foreign. Leipa 

 in Bohemia. New York Island. 



Name. From (pctxh, a bean, and A/&-, 

 stone. 



Brit. Mus., Case 37. 



31. P. G. Horse-shoe Case, No. 1181. 



Pharmacochalzit, Hausmann. See Oli- 



VINITE. 



Phakmacolite, Phillips, Nicol, Haus- 

 mann. Oblique. Generally occurs in deli- 

 cate silky fibres. or acicular crystals forming 

 stellated groups: also botryoldal, or globu- 

 lar and stalactitic. Rarely in distinct crys- 

 tals. Colour white or greyish : often super- 

 ficially tinged red or violet by arsenate of 

 cobalt. Lustre vitreous. Translucent to 



PHARMACOSIDEEITE. 281 



opaque. Streak white. Fracture uneven. 

 H. 2 to 2-5. S.G. 2-64 to 2-73. 



Comp. Arseniate of lime, or Ca^ As + 6H = 

 arsenic acid 51-11, lime 24-89, water 24-00 = 

 100. 

 Analysis, from Wittichen, by Klaproth ; 

 Arsenic acid. . . . 50-54 



Lime 25-00 



Water 24-46 



100-00 



BB is almost wholly volatilized, -mth 

 dense white arsenical fumes. 



Readily soluble, with efifervescence, in 

 nitric acid. 



Localities. Andreasberg in the Harz. 

 Riegelsdorf and Gliicksbrunn, in Thviringia. 

 St. Marie-aux-Mines, in the Vosges. Wit- 

 tichen in Baden, Joachimsthal in Bohemia. 

 Hesse. 



Name. From (^i^^f^t'Ocxov, poison, and Xidos, 

 stone ; in allusion to its containing arsenic. 



Brit. Mus., Case 56. 



Pharsiacosiderite, Hausmann, or ar- 

 seniate of iron. Cubical; primary form 

 the cube. Cleavage cubic, imperfect. Ge- 

 nerally occurs crystallized in cubes : rarely 

 massive. Colour various shades of green, 

 inclining to yellowish-, and brownish green. 

 Lustre vitreous. Semi-transparent to opaque. 

 Streak pale olive-green or yellow. Pyro- 

 electric. Fracture uneven or imperfect- 

 conchoidal. H. 2-5. S.G. 2-9 to 3. 



Fig. 327. 



Fig. 328. 



Comp. FeSAs + F^e3As2 + 18H (Berze- 



lius) : or Fe, ¥e As + 6H ( Gmelin). 

 Analysis, from Cornwall, by Berzelius : 

 Arsenic acid . . . 38-00 

 Phosphoric acid . . . 0'70 

 Peroxide of iron . , . 40-56 

 Oxide of copper . . .0-60 



Water 19-57 



Matrix. . , . .0-35 



99-78 

 BB on charcoal, gives off strong arsenical 

 odours, and fuses to a metallic, grey mag- 

 netic slag, which dissolves in borax or 

 microcosmic salt, emitting an arsenical 

 odour, and exhibiting an iron reaction. 

 Readily soluble in muriatic or nitric acid. 



