Chalcocite ps. Covellite
Butte Mines, Silverbow County, Montana, USA
Thumbnail, 2.8 x 2.2 x 1.3 cm
Ex. Jennie Areson
Chalcocite has totally pseudomorphed fine, tabular crystals of covellite in this rare complete replacement that is, shockingly, not as ugly as most of them tend to be! The specimen is highlighted by a doubly-terminated crystal measuring 2.5 cm in length and exhibit a brownish gray color with faint hints of blue. Significant pseudomorph, and a significant US thumbnail specimen.