Cerussite

Cerussite from the Blackwoods open cut, Broken Hill, New South Wales, Australia, measuring 135 × 72 × 68 mm and weighing 939 grams.

Cerussite is a lead carbonate that forms as Galena oxidises near the surface, commonly developing the distinctive twinned, reticulated crystal growths the species is known for among secondary lead minerals. The Blackwoods open cut exposed part of Broken Hill's oxidised zone directly to weathering, and open-cut workings like this one have historically produced some of the field's better Cerussite, often reaching a useful size, as this near-kilogram piece does.

This specimen comes from the David Vince Collection. A substantial, well-formed Cerussite from a named Broken Hill open cut is a genuinely useful reference piece, both for its size and for the documented locality behind it.