Jewel-like DioptaseTsumeb, Namibia A mid-sized, cabinet specimen, this jewel-like treasure displays a rich carpet of dioptase crystals entirely covering the surface. Lustrous and vivid green, the specimen has an excellent mound formation and horizon line. The locality of Tsumeb is the most sought-after for this mineral and the present example is an African classic. Measuring 3.5 x 2.4 x 1 in (9 x 6 x 2.5 cm) Apanied by a custom-fitted stand.