Secondary mineral, Cu3(CO3)2(OH)2; sp. gr. 3.7–3.9; hardness 3.5–4.0; monoclinic; various shades of deep azure blue; light-blue streak; vitreous lustre; crystals often tabular or short prisms, and radiating aggregates; cleavage prismatic or pinacoidal; occurs in the oxidized zone of copper deposits, associated with malachite but less widespread; soluble in nitric or hydrochloric acid, with effervescence. It is a minor ore of copper.