What makes this Tsumeb dioptase so nice is the isolation of the bright, lustrous crystals to about 1 cm on a starkly contrasting matrix. In addition, there are two generations of crystals here, which adds real pizzazz: an earlier generation of small, sparkling crystals, and some later, larger, SUPERB ones (to one cm tip-to-tip). As with all diops, better in person than in the photos... 5.5 x 4.5 x 3.5 cm