GUIDE TO THE MIXERALOGIC COLLECTIONS 55 



black, brown and yellow. The streak is yellowish brown to white 

 and the luster resinous. 



Sphalerite occurs in both crystalline and sedimentary rocks 

 and is frequently associated with galena. Such an association 

 is found in the extensive deposits of Missouri, Wisconsin, Iowa 

 and Illinois. Sphalerite is found in several localities in England 

 and Germany, also in Hungary, Sweden, Spain, etc. In New 

 York it is found in small quantities in a number of places, not- 

 ably at Wurtzboro, Sullivan co., Ellenville, Ulster co., at the 

 Ancram lead mine in Columbia county, in the limestone of 

 Lockport, Niagara co., and with calamin at Bethlehem Pa. 



Besides being an important ore of zinc, sphalerite yields con- 

 siderable cadmium. 



Cinnabar HgS 



The sulfid of mercury, cinnabar, contains 13.8$ sulfur and 86.2$ 

 mercury. 



The mineral is rarely found in hexagonal crystals of the rhom- 

 bohedral-trapezohedral group; it is commonly met with in 

 granular or earthy masses sometimes incrusting or as an 

 earthy coating. Cinnabar is very heavy (G=8.-S.2); this and its 

 brilliant red streak usually serve to identify it. The color is 

 cochineal-red to reddish brown and sometimes even inclining to 

 black; the luster is adamantine to dull. 



Cinnabar occurs in a variety of rock formations, being found 

 in slate, shale, granite and porphyry, where it is associated with 

 other sulfids. The principal localities are Almaden, Spain, 

 southern Russia, southern Austria, China, Peru, and Mexico. 

 ( !alifornia furnishes most of the American output. 



cinnabar is a valuable ore of mercury and was formerly 

 ground for a pigment called vermilion. The pigment is now pro- 

 duced artificially. 



Greenockite CdS 



GrecnocUite, the sulfid of cadmium, contains 22.3 '. sulfur and 

 77.7$ cadmium. 



It usually occurs as a bright yellow powder coating Bphalerite 

 and rarely in dull yellow hexagonal crystals of the hemimorphic 

 group. The crystals arc nearly transparent and of a resinous 

 luster. 



