often also 1 or 2 per cent, of sulphuret of cadmium, espe 

 cially the red variety. Infusible alone and with borax 

 Dissolves in nitric acid, emitting sulphuretted hydrogen 

 Strongly heated on charcoal yields fumes of zinc. 



Dif. This ore is characterized by its waxy luster, per- 

 feet cleavage, and infusibility. Some dark varieties look a 

 little like tin ore, but their cleavage and inferior hardness 

 distinguish them ; and some clear red crystals which re- 

 semble garnet are distinguished by the same characters and 

 also by their infusibility. 



Obs. Occurs in rocks of all ages, and is associated gen- 

 erally with ores of lead ; often also with copper, iron, tin, 

 and silver ores. The lead mines of Missouri and Wiscon- 

 sin, afford this ore abundantly. Other localities are in 

 Maine, at Lubec, Bingham, Dexter, Parsonsfield ; in New 

 Hampshire, at Eaton, Warren, Haverhill, Shelburne ; in 

 Vermont, at Thetford ; in Massachusetts, at Sterling, South- 

 ampton, and Hatfield ; in Connecticut, at Brookfield, Berlin, 

 Roxbury, and Monroe ; in New York, at the Ancram igad 

 iniilg, the Wurtzboro lead vein, at Lockport, Root, 2 miles 

 s. e. of Spraker's basin, in Fowler, at Clinton ; in Pennsyl- 

 vania, at the Perkiomen lead mine ; in Virginia, at Austin's 

 lead mine, Wythe county ; in Tennesse, near Powell's River, 

 and at Haysboro. 



This ore is the Black Jack of miners. 



Uses. Blende is a useful ore of zinc, though more diffi- 

 cult of reduction than calamine. By its decomposition, 

 (like that of pyrites,) it affords sulphate of zinc or white 

 vitriol. 



ziwcite.— red zinc ore. — Red oxyd of zinc. 



Trimetric. Usually in foliated masses, or in disseminated 

 grains ; cleavage eminent, nearly like that of mica, but the 

 laminae brittle, and not so easily separable. 



Color deep or bright red ; streak orange -yellow. Luster 

 brilliant, subadamantine. Translucent or subtranslucent. 

 H=4 — 4-5. Gr=5'4 — 5*56. Thin scales by transmitted 

 light deep yellow. 



Composition : zinc 80*3, oxygen 19*7=100. Infusible 



What is the action of zinc blende before the blowpipe 1 How is it dis- 

 tinguished 1 How does it occur 1 What is the appearance of red zinc 

 ore? its compos 1 ' tion? 



