278 Copper Minerals from Arizona. 



branching coralloid form, in groups of indistinct crystals, beau- 

 tified by a red amorphous coating of cuprite, often 1 to 2 mm. 

 in thickness, which is again enveloped in a thin white coating of 

 kaolin, or, as is frequently the case, with an alteration of mala- 

 chite after cuprite ; in both instances the cuprite and copper 

 protruding through the other coating. 



Aurichalcite, from Copper Queen Mine, is found lining and 

 covering cavities from two inches to seven and eight across (5 

 to 20 cm). It forms beautiful tufts and radiations of a light 

 green, and bluish green color, or is also associated with opaque 

 white calcite crystals in limonite cavities. The crystals, in the 

 tufts, are from 2 mm. to 4 mm. high, and for beauty of associa- 

 tion rival anything yet found. 



Cerusite is abundant at the Flux Mine in Pima Co., where it 

 occurs in wonderful masses and veins of a pure snowy white 

 color. Solid blocks are taken out a foot square, and weighing 

 from 50 to 60 lbs., made up entirely of crystals from 1 to 4 cm. 

 in length, although the form is not distinct, except in occasional 

 cavities. 



One interesting group 10 cm. square is beautifully tinted with 

 green by a deposit of carbonate of copper. The crystals are 

 very perfect but indistinct. In respect to quantity of material 

 these specimens are unsurpassed. 



At the Belle Mine, Yavapai County, cerusite is also plentiful, 

 but is not so white, and usually covered with a brown coating. 



I am indebted to Messrs. Adams, Shaw and Nivens for in- 

 formation and specimens. 



[All these mineral varieties were illustrated with a large set of very ele- 

 gant specimens.] 



