52 



NEW YORK STATE MUSEUM 



it can be readily separated into thin, flexible, nonelastic scales. 

 Orpiment is soft (H-l.5-2), slightly sectile and has a resinous or 

 pearly luster. 



It is often found associated with realgar. The principal 

 localities are Hungary, Borneo, Turkey; also Wyoming, Utah 

 and Nevada. It is found in the form of powder at Edenville 

 N. Y. 



Stibnite (antimony glance) Sb 2 S 3 



Stibnite is the trisulfid of antimony containing sulfur 2S.'W. 

 antimony 71.4$. 



It is found in orthorhombic crystals of prismatic habit; a 

 typical termination is shown in fig. 160. The crystals, which 

 are frequently acicular, show a tendency to arrange themselves 

 in radiating and reticulated groups (pi. 9 2 , 10 2 ). 

 /l \ They are grooved and striated vertically and are 

 / / \ sometimes bent and twisted. The color and streak 

 fr^l (V are lead-gray and the luster metallic with bril- 

 liant reflecting surfaces. Stibnite is quite soft, 

 the hardness being about 2, and has an easy 

 I cleavage parallel to the vertical axis. It often 



Fig i6o occurs in massive forms coarse or fine columnar 

 stibnite an( j sometimes granular. 

 Stibnite occurs in Hungary, Japan and New South Wales; 

 also in Nevada, Idaho, Utah, California, Arkansas and Nova 

 Scotia. 



Stibnite is the chief source of antimony and is also used 

 quite extensively in the production of safety matches, per- 

 cussion caps, fireworks and rubber goods, and in the refining 

 of gold. 



SULFIDS, ETC. OF THE METALS 



Galena (galenite, lead glance) PbS 



This important mineral is the sulfid of lead, containing sulfur 

 ISAfo and lead 86.6$. 



It is found crystallized and massive and is characterized by a 

 very marked cubic cleavage (pi. 11J. The crystals, some of 

 which are shown in fig. 161-63 are isometric, the cube and 

 octahedron being the prevailing forms. The crystal group 

 shown in pi. 14 1? gives some idea of the crystal habit and irreg- 



