Cornubite is a rare secondary copper arsenate mineral with formula: Cu₅(AsO₄)₂(OH)₄. It was first described for its discovery in 1958 in Wheal Carpenter, Gwinear, Cornwall, England, UK. The name is from Cornubia, the medieval Latin name for Cornwall. It is a dimorph of Cornwallite, and the arsenic analogue of pseudomalachite.