OXIDKS 



Cuprite may o\idi/e to CuO, the black oxide of copper, tenorito, 

 <u l>y tin action of percolating waters containing carbon dioxide 

 l>t- oxidi/.ed and transformed to the carbonate-, cither malachite 

 or a/urite, as is illustrated by the pseudomorphs of malachite 

 after cuprite of Chessy, France, some of which still contain a 

 central nucleus of cuprite. 



It occurs in good crystals at Bisbee, Arizona; in the Lake 

 Superior region ; and along the border of the trap of the Atlantic 

 coast, as at Somerville, New Jersey ; at New Haven, Connecticut. 

 Elongated, capillary, distorted cubes occur at Morenci, Arizona, 

 in plushlike mats, forming the variety known as chalcotrichite. 

 Noted European localities are Cornwall, England, where beautiful 

 crystals with complicated and rare forms are found ; also Chessy, 

 France, in individual crystals, combinations of the octahedrons 

 and the rhombic dodecahedron. 



Cuprite is an important ore of copper. 



ZINCITE 



Zincite. Oxide of zinc, ZnO ; Zn = 80.3, O = 19.7 ; Hexag- 

 onal; Type, Dihexagonal Polar; c = 1.621 ; 0001 A 1011 = 61 

 54'; Forms, p (lOll), m (lOlO), 

 c (0001) ; Cleavage, basal and pris- 

 matic ; Brittle, fracture subconchoi- 

 dal ; H. = 4-4.5 ; G. = 5.43 ; Color, 

 deep red to orange ; Streak, orange ; 

 Luster, adamantine ; Transparent to 

 nearly opaque; Optically (+). 



B.B. Infusible. In R. F. with 

 soda and borax on coal yields a zinc 

 coat. Easily soluble in hot acids with- 

 out effervescing. Generally shows 

 manganese with the fluxes. 



General Description. Crystals 

 are very rare, usually simple hemi- 

 pyramids, as both the base and prism 

 are rare faces on natural crystals. 

 Crystals of zincite appearing as flue 

 or slag products are much more com- 

 plex than the natural crystals. 



Pure oxide of zinc is white, but 



Fio. 413. Zincite Crystal from 

 Franklin, New Jersey. 



