132 DESCRIPTIONS OF MINERALS. 



Small specimens of native copper have been found in the 

 States of New Jersey. Connecticut, and Massachusetts, where 

 the Triassic formation occurs. One mass from near Sonier- 

 ville, X. J., weighs T8 pounds, and is said originally to have 

 weighed 1.28 pounds. Within a few miles to the north of 

 New Haven, Conn., one mass of 90 pounds, and another of 

 200, besides other smaller, have been found in the drift, all 

 of which came from veins in the trap or associated Triassic 

 sandstone. Xear Xew Brunswick, X. J., a vein or sheet of 

 copper, from a sixteenth to an eighth of an inch thick, has 

 been observed and traced along for several rods. 



Xative copper occurs also in South Australia : it is stated 

 that a single train from the Moonta Mine carried away at 

 one time forty tons of native copper. 



Chalcocite. — Copper Glance. Vitreous Copper Ore. Redrutliite. 



Trimetric. I : 7=119° 35'. Cleavage 

 parallel to I, but indistinct. Also in com- 

 pound crystals like aragonite. Often mas- 

 sive. 



Color and streak blackish lead-gray ; often 

 tarnished blue or green. Streak sometimes 

 shining. H. =2*5-3. Gr. = 5 -5-5*8. 



Composition. Cu 2 S = Sulphur 20*2, cop- 

 per T9'8 = 100. B. B. on charcoal gives off 

 fumes of sulphur, fuses easily in the exte- 

 rior flame ; and after the sulphur is driven 

 off, a globule of copper remains. Dissolves 

 in heated nitric acid, with a precipitation of the sulphur. 



Biff. Resembles argentite, but it is not sectile, like that 

 ore. and they afford different results before the blowpipe. 

 The solution of the ore in nitric acid covers an iron plate 

 (or knife blade) with copper, while a similar solution of the 

 silver ore covers a copper plate with silver. 



Obs. Occurs with other copper ores in beds and veins. 

 At Cornwall, splendid crystallizations occur. Siberia, Hesse, 

 Saxony, the Banat, Chili, etc., afford this ore. 



In the United States, a vein affording fine crystallizations 

 occurs at Bristol, Conn. Other localities are' at TVolcott- 

 ville, Simsbury, and Cheshire, Conn. ; at Schuyler's Mines, 

 and elsewhere. X. J. ; in the U. S. copper-mine district, 

 Blue Ridge, Orange County, Virginia; between Xew Ma*rket 

 and Taney town, Maryland ; and sparingly at the copper 



