Home > Copper Minerals – January 21 > MS1497 Chalcosiderite

Chalcosiderite - Sold


Chalcosiderite is a copper iron phosphate mineral, the name itself a combination of the Greek roots chalco for copper and sider for iron (Ullman, 1814). Chalcosiderite and turquoise have the same crystal structure. As the discovery of chalcosiderite predated X-ray diffraction and early turquoise specimens were massive, the isomorphous relationship between chalcosiderite and turquoise remained unrecognized until the discovery of turquoise crystals in Virginia (Schaller, 1912).

A open pocket in iron stained quartz matrix hosts a 15 by 15 mm druse of forest green chalcosiderite. The chalcosiderite crystals form tight spherical aggregates, and individually measure about 1 mm. From the co-type locality. Formerly in the collection of Victor Hoffman.