Calcite with Dioptase

A highly lustrous mound of closely interpenetrating, snow-white rhombic Calcite crystals, averaging between 2 and 2.5 cm on edge overgrowing a hidden core of pinkish Calcite or Dolomite.  A splendid Calcite from the Tsumeb mine in Namibia, the faces of which are themselves covered in micro-rhombohedral crystals, all with a high lustre and intense buttermilk-white purity. Scattered over the specimen are five pinhead patches of micro-crystalline Dioptase which appear a more bluish green than usual because of their tiny size and the internal reflection of the underlying white Calcite.  A Calcite beautiful for its form, arrestingly buttermilk-white colour, and terrific lustre from Tsumeb.