Chalcocite

Unknown Owner

A cluster of fine somewhat iridescent chalcocite crystals without matrix. Some damage present as seen. Still very nice classic example from this long closed North American occurrence.The Flambeau Mine in Rusk County, Wisconsin, was an open pit copper and gold mine that operated from 1993 to 1997. The deposit was a volcanogenic massive sulfide ore body hosted in Precambrian volcanic rocks. During mining, rich secondary enrichment zones were encountered that produced copper sulfide minerals. Chalcocite occurs at the mine as dark gray to black metallic masses and crystalline coatings formed by the alteration and enrichment of primary copper minerals such as chalcopyrite. Specimens from the Flambeau Mine are valued by collectors for their well developed sulfide mineralization and associations.