Bornite

Description

Bornite (blue chalcopyrite). A mineral from the copper sulfide group. Freshly fractured, it has a bronze-red color, but under the influence of oxidation, it takes on characteristic blue, purple, green, and other iridescent hues. Bornite forms under conditions of high-temperature hydrothermal processes. In near-surface zones, it undergoes chemical alteration, resulting in the formation of chalcosine and covellite.