When it comes to Dioptase, there is no locality greater or more prolific than Tsumeb for quantity and quality. This specimen exhibits the top emerald green color (impossible to replicate in photos) that made these specimens so famous. The crystals themselves, are in very good condition overall, and even pass light when backlit. The final touch to these sharp, lustrous trigonal crystals is the fact that they are sitting on a mound of classic contrasting white Calcite on matrix. Ex. Brian Kosnar Collection.