296 METALS. 



curs in slender aggregated prisms, of a dark ead-gray color. Anothei 

 containing also arsenic, is called antimonial copper glance. 



Tennantitc- is a compound of copper, iron, sulphur, and arsenic. It 

 occurs in dodecahedral crystals, brilliant, with a dark lead-gray color 

 and reddish-gray streak. From the Cornish mines near Redruth and 

 St. Day. Domeykitc is arsenical copper. 



Selenid of Copper, is a silver-white ore, affording the horse-radish 

 odor of selenium before the blowpipe. It contains 64 per cent, of cop-' 

 per. From Skrikerum, Sweden. 



RED COPPER ORE. ^^2. ® 



Monometric. In regular octahedrons, and modified forma 



of the same. Cleavage octahedral. ! Also massive, and 



1 sometimes earthy. 



Color deep red, of various 

 shades. Streak brownish-red. 

 Luster adamantine or submetal- 

 lic ; also earthy. Subtranspa- 

 rent to nearly opaque. Brittle. 

 H=3-5— 4. Gr=6. 

 Composition : copper 88*8, oxygeu 1 1 •& Before the blow- 

 pipe, on charcoal, it yields a globule of copper. Dissolves 

 in nitric acid. The earthy varieties have been ' called tile 

 ore, from the color. 



Dif. From cinnabar it differs in not being volatile before 

 the blowpipe ; and from red iron ore, in yielding a bead of 

 copper on charcoal, and copper-reactions. 

 *-"- Qbs. Occurs with other copper ores in the Bannat, Thur- 

 ingia, Cornwall, at Chessy near Lyons, in Siberia, and Bra- 

 zil. The octahedrons are often green, from a coating of 

 malachite. 



In the U. States, it has been observed crystallized and 

 massive, at Schuyler's, Somerville, and the Flemington cop- 

 per mines, N. J. ; also near New Brunswick, N. J. ; at 

 Bristol, Ct. ; also near Ladenton, Rockland county, N. Y. 

 Black Copper. Tenorite. An oxyd of copper, occurring 

 *.. O a s a black powder and in dull black masses, and botryoidal 

 m J /concretions, in veins or along with other copper ores- From 

 Cornwall, and also the Vesuvian lavas. It is an abundant 

 ore in some of the copper mines of the Mississippi valley 

 and yields 60 to 70 per cent, of copper. It results from the 



6U 



What is the crystallization of red copper ore 1 Of what does it coo 

 it '( How does it differ from cinnabar and re 1 iron ore? 



