Covellite
Leonard Mine, Butte Mining District, Silver Bow County, Montana, USA
5.6 x 3.4 x 2.9 cm. Perched aesthetically on a sulfide matrix are thin, tabular, iridescent, purple crystals of covellite, to 1.8 cm in length. Covellite crystals from Butte, like this, are highly coveted and arguably the world's best for the species with only a few exceptions from Sardinia, but even those do not get as sharp and machined-looking ...
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