Chalcanthite 35 pieces assorted box from Poland.

The mineral chalcanthite is a hydrated copper sulphate with the chemical formula CuSO4 · 5 (H2O). The green, green-blue or blue chalcanthite has a glaze, a white stripe color and the mineral has an imperfect fission (on [110]) and an indistinct cleavage (on [111]). The average density is 2.21 and the hardness is 2.5. The crystal system is triclene and the mineral is not radioactive. Because the mineral is hygroscopic, it must be stored in a closed room. The name of the mineral chalcanthite is derived from the Greek words chalcos, "copper" and anthos, which means "flower". Chalcanthite is formed in arid climates as a secondary mineral in rapidly oxidizing copper-containing rocks. It also arises in outflow rocks. The type of location of chalcanthite is the Chuquicamata mine, Calama, El Loa province, Antofagasta, Chile. The mineral is also found in the Gera district, Thuringia, Germany, in the volcano Tolbatschik on Kamchatka, Russia and in the Planet mine, La Paz County, Arizona, United States and in the Skouriotissa mine (Cyprus).