Azurite

Azurite from Mineral Hill, Condobolin, New South Wales, Australia, measuring 70 × 55 × 27 mm and weighing 116 grams.

Azurite is a copper carbonate that forms in the oxidised, near-surface zone of copper deposits, typically alongside its more stable green relative, Malachite, into which it slowly alters over time given enough exposure to water and air. Mineral Hill is a polymetallic deposit worked for copper, gold and silver, and like most copper orebodies of its kind, its upper levels have produced a characteristic suite of oxidised copper minerals from weathering of the primary sulphides below.

This specimen comes from the Allan Waldon Collection. Good Azurite from inland New South Wales localities like this one doesn't come up as often as the better-known South Australian copper fields, which makes a piece like this a worthwhile addition for anyone collecting Australian copper minerals specifically.