ORES OF COPPER. 141 



This mineral receives a high polish and is used for tables, 

 mantelpieces, vases ; and also ear-rings, snuff-boxes, and va- 

 rious ornamental articles. It is not much prized in jewelry. 

 At Versailles there is a room furnished with tables, vases, 

 and otter articles of this kind ; and similar rooms are to be 

 found in many European palaces. 



Malachite is sometimes passed off in jewelry as turquois, 

 though easily distinguished by its shade of color and much 

 inferior hardness. It is a valuable ore when abundant ; but 

 it is seldom smelted alone, because the metal is liable to es- 

 cape with the liberated volatile ingredient. 



Azurite. — Blue Copper Carbonate. Blue Malachite. 



Monoclinic. In modified oblique rhombic prisms, the 

 crystals rather short and stout; 

 lateral cleavage perfect. Also mas- 

 sive. Often earthy. 



Color deep blue, azure blue, Ber- 

 lin blue. Transparent to nearly 

 opique. Streak bluish. Lustre 

 vitreous, almost adamantine. Brit- 

 tle. H. =3-5-4-5. G. = 3o-385. 



Composition. Cu 3 0. C 2 + H 2 = 

 Carbon dioxide 25'6, copper oxide 

 69 - 2, water 5*2. B.B. and in acids like the preceding. 



Obs. Azurite accompanies other ores of copper. Chessy, 

 France, has afforded fine crystals ; found also in Siberia ; in 

 the Banat ; near Redruth in Cornwall ; at Phoenixville, Pa., 

 in crystals ; in Wisconsin near Mineral Point ; as incrusta- 

 tions, and rarely as crystals, near Sing Sing, N. Y. ; near 

 New Brunswick, N. J. ; near Nicholson's Gap, in the Blue 

 Ridge, Pa. 



When abundant it is a valuable ore of copper. It makes 

 a poor pigment as it is liable to turn green. 



Aurichalo'te (Buratite) is a hydrous copper-and-zinc carbonate, or a 

 cuprous hydrozincite, pale green to sky-blue in color ; from the Altai, 

 Eetzbanya, Chessy in France, Tyrol, Spain, Leadhills in Scotland, and 

 Lancaster, Pa. 



Dioptase. — Copper Silicate. 



Rhombohedral. R/\R — 1^Q° 24'. Occurs in six-sided 

 prisms with rhombohedral terminations. Color emerald- 

 green. Lustre vitreous. Transparent to nearly opaque. 

 H.=5. G. =3 -28-3 -35. 



