Aurichalcite with Calcite

This specimen is Aurichalcite with Calcite from the 79 Mine, Gila County, Arizona, U.S.A., measuring 63 x 50 x 22 mm and weighing 58 g. It is recorded with the David Vince Collection and Willyama Minerals. Aurichalcite is a copper-zinc carbonate that typically forms delicate sprays of pale blue-green acicular crystals in the oxidised zones of copper-zinc deposits. The 79 Mine in Gila County is a recognised locality for well-formed examples of the species. Its association with Calcite seen here is a common pairing at such localities, the white carbonate providing a contrasting host for Aurichalcite's distinctive colour and acicular habit. At 63 x 50 x 22 mm and 58 g, the specimen is a compact piece. Aurichalcite's delicate, acicular crystal sprays are fragile and susceptible to damage from handling or vibration, so a secure, undisturbed display position is strongly advised. The specimen's documented provenance includes both the David Vince Collection and Willyama Minerals.