Dioptase with Calcite

Unknown Owner

Help improve this recordNo owner is registered for this specimen yet. If it's yours or you know more about it, you can add the owner, provenance, publications and other details.

Since the famous discovery of Dioptase on snow white Calcite at the Tsumeb mine in, I think, the late 1970s, it is easy to forget the many other associations and morphologies which occur with Dioptase. This miniature is a terrific example of deep emerald green crystals forming a quite jumbled, busy display, mixed with colourless, transparent to translucent, rhombic Calcite crystals and a dusting of bright spring leaf green Conichalcite. The Dioptase, a copper silicate, is a darker shade of emerald green than more commonly seen at Tsumeb and forms equant crystals of varying size. It also occurs as micro-crystalline clusters coating earlier generation Dioptase crystals. The relatively random mix of Calcite and Dioptase produces a brecciated appearance, but through chemical paragenesis, not tectonic comminution. The specimen’s base shows an entirely different looking specimen, with an attractive lime green hackly mass of copper arsenates (probably mixed Conichalcite and Duftite) surrounded by outer encircling halos of Dioptase followed by Calcite.