Liroconite is a complex mineral: Hydrated copper aluminium arsenate hydroxide, with the formula Cu<sub>2</sub>Al[(OH)<sub>4</sub>|AsO<sub>4</sub>]·4(H<sub>2</sub>O). It is a vitreous monoclinic mineral, colored bright blue to green, often associated with malachite, azurite, olivenite, and clinoclase. It is quite soft, with a Mohs hardness of 2–2.5, and has a specific gravity of 2.9–3.0.
thumb|left|Vugs in [[gossan lined with lustrous, blue-green liroconite blades and sparkly, dark blue clinoclase microcrystals from Wheal Gorland (size: 3.4 × 3.0 × 2.0 cm)]]
It was first identified in 1825 in the tin and copper mines of Devon and Cornwall, England. Although it remains quite rare it has subsequently been identified in a variety of locations including France, Germany, Australia, New Jersey and California.
It occurs as a secondary mineral in copper deposits in association with olivenite, chalcophyllite, clinoclase, cornwallite, strashimirite, malachite, cuprite and limonite. The crystal structure consists of a framework of AsO<sub>4</sub> tetrahedra, Jahn-Teller-distorted [CuO<sub>2</sub>(OH)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>] octahedra and [AlO<sub>2</sub>(OH)<sub>4</sub>] octahedra.
250px|Unit cell of liroconite
See also
- Kernowite – an isostructural mineral with iron in place of aluminium