Wulfenite (w. calcite and conichalcite-duftite)

calcite; conichalcite-duftite

A matrix-free specimen of butterscotch-coloured wulfenite, dominated by a large, square, tabular crystal (25 mm on edge) with a smaller crystal in parallel growth extending from the righthand side (as photographed). Part of the large crystal is frosted with microcrystals of white calcite and localised crusts of olive-green conichalcite-duftite. The arsenate has not been analysed, but its association with a lead mineral (in this case wulfenite) favours duftite over conichalcite.

The specimen is in the collection of Sharon and Eugene Cisneros.