290 



A. F. Rogers — Delafossite. 



Art. XXV. — Delafossite, a Cuprous Metaferrite from Bisbee, 

 Arizona ; by Austin F. Rogers. With an analysis by Gr. S. 

 Bohart. 



Mr. Wm. L. Tovote, geologist of the Old Dominion Mining 

 Company of Grlobe, Arizona, kindly sent me for identification 

 and description some specimens of what was thought to be a 

 new mineral from Bisbee, Arizona. The mineral is hexagonal 

 in crystallization, and on analysis proves to have the formula 

 CuFe0 2 . In 1873 Friedel* described a Siberian mineral with 

 the composition Cu 2 O.Fe 2 3 , to which he gave the name 

 delafossite. The Bisbee mineral must be referred to delafos- 

 site, and though not a new mineral the results obtained warrant 

 the establishment of delafossite as a distinct mineral species.f 



Fig. 1. 



Fig. 2. 



Occurrence. — The mineral under discussion was found by 

 Mr. Tovote in a stope above the 14th level of the Hoatson shaft 

 of the Calumet and Arizona property near the Copper Queen 

 line. According to Mr. Tovote^: it occurred in a great mass of 

 white kaolin and ferruginous clay at about the lowest zone of 

 oxidization. The surrounding country rock is limestone. The 

 associated minerals include copper, cuprite, and hematite ; the 

 hand specimens contain copper and hematite. 



Crystallography. — The mineral is found in more or less dis- 

 tinct crystals and subbotryoidal crystal aggregates on massive 

 hematite. The crystals are hexagonal and greatly resemble 

 hematite crystals, for_they consist of a pinacoid {0001} with 

 a rhombohedron {1011}, and are tabular to equidimensional 

 in habit. There are also composite prismatic crystals with con- 

 cave pinacoidal faces which suggest the " eisenrosen." Fig. 1 

 represents a typical crystal. The hexagonal prism J 1010}, 



* Comptes Rendus, vol. lxxvii, p. 211. 



f In Dana's System of Mineralogy, 6th edition (p. 259), and in Hintze's 

 Handbuch der Mineralogie (vol. i, p. 1939) it is included in the Appendix to 

 Oxides. 



^Mining and Scientific Press, vol. cii, p. 206, 1911. 



