Conichalcite, CaCu(AsO₄)(OH), is a relatively common arsenate mineral related to duftite (PbCu(AsO₄)(OH)). It is green, often botryoidal, and occurs in the oxidation zone of some metal deposits. It occurs with limonite, malachite, beudantite, adamite, cuproadamite, olivenite and smithsonite.