108 BULLETIN 42, UNITED STATES NATIONAL MUSEUM. 



ARIZONA COPPER DISTRICT. 



The copper iniues of Arizona are remarkable as baviug produced 

 large (juantities of oxidized ores. These ores occur for the most part 

 in large deposits at aud near the surface and are extracted by the 

 simpliest quarrying operations. They coutaiu 10 to 15 per cent, of cop- 

 l)er, aud, owing to their oxidized condition, a single fusion iu a water- 

 jacketed cupola furnace produces pig copper carrying from 07 to 98 

 per cent, of the metal. In many instances no flux is required, since a 

 mixture of tbe ore can be made that will be self-fluxing. In some 

 cases, however, limestone is used. It will thus be seen that both the 

 mining and smelting are exceedingly simple and inexpensive. Fuel, 

 however, is very dear, having cost over $50 per ton at some of the 

 works. 



This region is illustrated by a collection from the Copper Queen 

 mine, Bisbee, Cochise County, taken by Mr. B. Williams, which shows 

 a great variety of the ores. The collection begins with a sample of 

 free copper, which has evidently been produced as a secondary product 

 from the other copper minerals. It then follows on through various 

 stages of oxidation to malachite. 



COPPER QUEEN MINE AND SMELTEU. 



Ore. 

 (1) Free copper, crystallized on siliceons limonite. (r)6043.) 



Oxidized ore. 



(1) Cuprite, crystallized on limonite. Tbe crystals are well-developed octahedrons 

 ■with cubic faces, mostly iu separate individuals. (56050.) 



(2) Cuprite, in crystalline coating and layers, on limonite. (56047.) 



(3) Azurite, crystallized. (560.52.) 



(4) Azurite, crystallized, malachite, limonite; the azurite occurs in the interior of a 

 cavity surrounded by tbe malachite and limonite. (56051.) 



(5) Azurite, malachite, limonite ; the azurite occurs in separate crystalline aggre- 

 gates on fibrous globular malachite. (56056.) 



(6) Malachite, azurite, oxide of manganese. A mixture of malachite and azurite, 

 coated on the exposed surface with oxide of manganese. (56057.) 



(7) Malachite, a fibrous globular coating on the interior of a cavity. (56060.) 



(81 Malachite, a fibrous globular malachite in a cellular mass aud showing the 

 interior of one large cavity. (56059.) 



(9) Malachite, with a little azurite, cellular, massiv^e; showing a small elongated 

 cavity with stalactites. (56058.) 



(10) Average sample, from opeu surface cut. (.56069.) 

 (U) Average sample, from lower working. (56070.) 



(12) Average sample, representing a 3-daysruu of the furnaces; the charge being 

 opeu cut ore 30 pounds, lower workiugs ore 245 pounds, limestone 25 pounds. (.56008.) 



Slag. 

 (1) From the blast furnace. (56071.) 



A sample of the pig copper may be seen in the collection from the 

 Ausonia works. 



