MINERALOGY. 463 



sociated with ores of silver, lead, iron, and copper. Serves 

 to represent Arsenious Acid (White Arsenic, the well- 

 known poison), and Sulphurets of Arsenic (Orpiment or 

 King's Yellow, Yellow Sulphuret) and Realgar (Red 

 Sulphuret) of Arsenic. Arsenious acid, with oxyd of 

 copper, produces a fine pigment called Scheele's Green. 



Smaltine Tin- White Arsenical Cobalt occurs 

 in crystalline, massive structures, also in reticulated or 

 other imitative shapes. Color tin-white, inclining to 

 steel-gray; streak, grayish-black ; luster, metallic, opaque. 

 By burning emits copious arsenical fumes ; colors glass 

 in a fluid state, blue ; also gives a blue color to porcelain 

 and stone-ware. Localities France, England, Sweden, 

 and Germany ; especially at Joachimstahl, in Bohemia, 

 where it is found in veins associated with other ores of 

 cobalt and ores of silver and copper. In Connecticut it 

 occurs with copper nickel in veins traversing gneiss. 

 With silex and potash it affords smalt ; is scarce, and 

 highly valued. 



Copper Pyrites Sulphuret of Copper and Iron. 

 Form and composition compound complex crystal ; also 

 globular, massive, stalactitate, granular, sometimes im- 

 palpable. Color brassy-yellow or varied brown ; luster 

 shining, opaque ; streak, greenish-black. On being 

 roasted gives off fumes of burning sulphur. Colors glass 

 green. II. =. 3.5 to 4.0. G. = 4.1 to 4. 3. Occurs 

 in granite, and nearly all the other formations, in veins 

 or beds associated with other copper ores ; foreign local- 

 ities Ross Island, Kilkenny, Ireland, Norway, Sweden, 

 South Tyrol, Hungary, Siberia, Freiburg in the Hartz 

 mining regions, etc. Fine crystallizations occur in the 

 Bristol copper mine, Connecticut, in granite, also at 

 Cheshire, in red sandstone, and in the same State with 



