Dioptase      Tsumeb Mine, Tsumeb, Otjikoto Region, Namibia, South West Africa.  Ex. Thomas G. Fowler collection.  A large thumbnail sized plate of small crystals with liberal tan colored smithsonite overgrowths.  It measures 3.5 x 2.2 x .7 cm overall.  Mounted in a perky box.  No damage.  Lower luster than most.  Great price.   $90