74 PHYSIOGRAPHY. 



Lustre metallic. Colour blackish lead-grey. Streak 



shining. 

 Perfectly sectile. Soft. Sp.Gr. =6-255, STROMEYER. 



Constituent parts, according to STROMEYER, 

 Silver 52-272. 

 Copper 30-478. 

 Iron 0-333. 



Sulphur 15-782. 



It occurs along with pyramidal Copper-pyrites, rhombo- 

 hedral Lime-haloide and rhorabohedral Quartz at Schlangen- 

 berg in Siberia, and is very rare. It was first described by 

 Professors HAUSMANN and STROMEYER. 



ARSENICAL BISMUTH. 



Arsenik-Wismuth. WERN. Syst. S. 56. 



Implanted globular shapes, massive : composition 

 thin columnar, impalpable, also curved lamellar. 

 Fracture imperfect conchoidal or uneven. 



Lustre resinous. Colour dark hair-brown. 



Rather brittle. Soft. Heavy. 



It decrepitates briskly before the blowpipe, emits an ar. 

 senical odour, and is finally converted into a glass, which 

 effervesces with borax. 



It occurs at Schneeberg in Saxony. 



ATACAMITE. 

 MALACHITE. 



Prismatic Atacamite, JAM. Syst. Vol. II. p. 343. Man. p. 

 104. Muriate of Copper. PHILL. p. 313. 



Prismatic. Combinations somewhat resembling 

 Fig. 21. ; often only the faces o and d, producing 

 a combination like Fig. 1. Inclination of o on & 



