cuprite

Cuprite is a mineral species consisting of copper(I) oxide, with the chemical formula Cu2O. It is the copper(I) oxide mineral and crystallizes in the cubic system. Cuprite is best known for its deep red to reddish-brown crystals, which commonly occur as octahedra or as crusts and masses on other minerals in oxidized zones of copper deposits.

In terms of physical properties, cuprite has a vitreous luster, a dark red color, and a red streak. It typically measures 3.5 to 4 on the Mohs scale of hardness and has a relatively high specific gravity of about 6.0. Crystals are usually well-formed in the cubic system, though more often they occur as aggregates or crusts rather than single, sharp specimens.

Formation and associations: cuprite forms as a secondary mineral in the oxidation zones of copper-bearing ore bodies. It commonly occurs with other copper oxides and carbonates, such as tenorite (CuO), malachite, azurite, chrysocolla, and native copper, reflecting the weathering and alteration processes that concentrate copper oxides at or near the surface.

Occurrence and significance: cuprite is found in copper mining districts worldwide and is highly prized by mineral collectors for its vivid red crystals. While it is a copper oxide mineral, it is not a major ore source in modern copper production; its value lies primarily in mineralogy and collection.

Etymology: the name cuprite derives from cuprum, the Latin word for copper, with the -ite suffix used for minerals.