Aldridgeite, a new mineral from the Block 14 open cut, Broken Hill, New South Wales

摘要

Aldridgeite, (Cd,Ca)(Cu,Zn)_4(SO_4)_2(OH)_6-3H_2O, is a new Cd-bearing sulphate mineral, the Cd analogue of serpierite, from the Block 14 open cut, Broken Hill, New South Wales. It occurs in cavities in a quartz-garnet-smithsonite matrix associated with niedermayrite and pyromorphite. Aldridgeite forms sprays of pale blue acicular crystals to 0.8 mm across. Individual crystals are up to 0.4 mm in length and 0.005 mm across. The crystals have a vitreous lustre and a pale blue streak. Mohs hardness is about 3 (estimated). The fracture is irregular and the tenacity is brittle.