DIOPTASE
Specimen dio-25
$ 90.00Dims: 1.3x1.1x0.9" (3.3x2.7x2.2 cm)
Wt: 0.7 oz. (20.6g)
Rodgerberg Mine, Guichab, Nr. Grootfontein, Namibia
This thumbnail specimen is a single large crystal of dioptase on a calcite base. This crystal is possibly the largest that I have seen, measuring 16mm in length. It has the usual intense green color, and appears translucent due to a great many internal fractures. It is transparent enough that from some angles in internal fracture will reflect a bright green sparkle. However, most of the crystals sparkle is due to reflection from its vitreous luster. The prismatic crystal has six sides and exhibits a rhombohedral termination - characteristic for dioptase, especially on one end. This end is also the most transparent, as the other end is cloudy from inclusions and internal fractures. There are also several black areas in the crystal. The crystals perfection is marred by barely perceptible damage to the "good" end, and significant damage to the other end. Also, the crystal appears to have formed after its host, which (once removed) left crystal impressions on the surface, including a cavity several millimeters deep.