Secondary Sphalerite

This specimen is Secondary Sphalerite from Broken Hill, New South Wales, Australia, measuring 62 x 39 x 28 mm and weighing 73 g. It is drawn from the David Vince Collection. Sphalerite, zinc sulphide, is the principal zinc ore mineral at Broken Hill, and the deposit is internationally known for it in its ordinary massive primary form. Secondary Sphalerite, as in this specimen, has instead been reformed or recrystallised through later alteration of the primary ore rather than deposited directly as original ore mineralisation, representing a distinct generation of the same species within the orebody's long and complex mineralising history. Such secondary generations are a documented feature of Broken Hill's geology, reflecting the multiple episodes of deformation and remobilisation the orebody has undergone since its formation. At 62 x 39 x 28 mm and 73 g, the specimen is a compact cabinet piece. Sphalerite is a relatively soft, brittle mineral and benefits from careful handling and a secure display mount. The specimen's documented provenance is the David Vince Collection.