Calcite, (w. Dioptase and Cuprite)

Mineral: Calcite, Cuprite, Dioptase
Chemistry: CaCO3
Size: 30 mm
Owner: Geoff Krasnov
Photographer: Geoff Krasnov

A druse of gemmy, emerald-green dioptase crystals is overgrown by a stepped, rhombic tablet of colourless to very pale-yellow calcite which, locally, is coloured by the dioptase.  

The calcite is also partly included by irregularly distributed patches of microscopic particles of cuprite (var. chalcotrichite), which formed on the calcite surfaces during an earlier stage of growth, and which now define incomplete but bright, orange-red phantoms.

This aesthetic and colourful specimen was originally in the collection of noted thumbnail collector Willard Perkins. It is from the second oxidation zone at Tsumeb.