Malachite

Malachite from Burra Open Pit Mine, Burra Burra, South Australia, Australia, measuring 65 × 65 × 70 mm and weighing 428 grams. This is a substantial specimen in relation to its dimensions, with a recognisable place in an Australian copper-mineral collection. The Burra attribution is central to its appeal, connecting a familiar mineral species with a specific South Australian mining locality.

Malachite is a copper carbonate hydroxide that forms during the alteration of copper-bearing minerals. It represents a later stage in the life of a deposit, when water and oxygen help redistribute copper near the surface. Its chemistry differs from that of copper oxides and sulphides, making it a useful companion to those minerals in a display that follows copper through different geological environments.

Rounded green lobes give the Malachite its distinctive botryoidal form, a term used for surfaces resembling a cluster of grapes. Here the broad curves are softened by a fine, velvety-looking texture. It is a lovely contrast of scale: a weighty piece with a surface that invites quite gentle, close observation, particularly where the lobes meet and form deeper green recesses. The specimen comes from the Anne McDonald Collection. That recorded ownership is part of the piece's story and belongs alongside the mine attribution. There is a satisfying combination here of substantial size, a defined Australian locality and a familiar secondary copper mineral, offering a useful focal specimen for a Burra group with the rounded green surface giving it an immediately recognisable character.