Crystals are transparent to translucent. The crystal habits include stubby crystals that are usually well formed prisms topped with the three faces of a rhombohedon. Prisms are six sided and usually not very long. Simple rhombohedrons are also common, at times a second rhombohedron will modify the primary rhombohedron faces producing a second set of three smaller faces. Crusts and massive forms are also seen.
Cleavage is perfect in three directions forming rhombohedrons.
Dioptase is a very beautiful mineral and it is one of the few minerals that can challenge the peerlessness of emerald's deep green. The mineral specimens that dioptase produces, however, are truly a treasure for anyone that likes deep green colors. Notable Occurrences include Tsumeb, Namibia. We also have an old Tsumeb collecton that contains some fine examples of dioptase.