A rarity of note from a recently acquired Tsumeb collection that we found in Germany two weeks ago, aside from the obvious colorful green dioptase inclusions there is an unknown green mineral coating the surface of the lustrous calcite rhombs. The rare mineral can be seen with the naked eye as a consistent covering of darker green specks than the dioptase beneath and only under a microscope is their unique form visible.

The olive green crystals are flake like blades exhibiting a good luster and spread out consistently across all surfaces. The dioptase inclusions consist of bright green micro crystals that are so proliferous that the calcite rhombs appear to be all green. The inclusions are present as distinct phantoms easily recognizable in those rhombs that display some crystal faces void of color, the clean faces allow you to see into the crystals where the inclusions in adjacent faces can be seen as perfect lines appearing millimeters beneath the exterior of the surface consistently following  the sharp calcite form.

I have had other dioptase in calcite from tsumeb but generally they have little luster if any at all, I have never seen a specimen that features so many small calcite rhombs like this, the overall luster is so much better due to so many additional crystal faces reflecting light creating a striking sparkle.

This specimen also exhibits good relief with elevated surfaces and resultant deep crevices all lined with calcite giving it more dimension that the typical flat plates that came out. There are only small imperfections to report, some cleavages near the peripheral edges and slight edge wear to isolated rhombs within.