Cuprite

Cuprite an oxide mineral composed of copper oxide Cu2O, and is a minor ore of copper. In spite of its nice color it rarely used for jewelry because of its low Mohs hardness of 3.5 to 4. It has a relatively high specific gravity of 6.1, imperfect cleavage and a brittle to conchoidal fracture. The luster is sub-metallic to brilliant adamantine.

It is a secondary mineral which forms in the oxidized zone of copper sulfide deposits. It known as ruby copper due to its distinctive red color.

Cuprite was first described in 1845 and the name derives from the Latin «cuprum» for its copper content.