Dioptase

calcite; conichalcite-duftite

A shard of siliceous matrix thickly encrusted with sparry white calcite which hosts an open vug lined with dioptase crystals (to 18 mm). The exposed calcite is locally dusted with apple-green conichalcite-duftite. Unfortunately there is damage to some of the peripheral dioptase crystals at the margin of the vug.

The specimen was number 140 in the collection of Clement Victor Latz, which was donated to the Australian Bureau of Mineral Resources (now Geoscience Australia) in 1976. There is no record of location in the mine, but the paragenesis is diagnostic for the second oxidation zone.