Dioptase

Transparent dioptase suitable for faceting is exceedingly rare, and stones are usually very small, often well under 1 carat. Carat weight thus heavily influences value when combined with strong color and clarity, but even tiny faceted stones are considered notable.

Color is the main attraction: a saturated, medium to medium-dark emerald-green with high translucency is ideal. Too dark or heavily included stones lose some of their visual impact, although rich color is still appreciated in specimens.

For faceted dioptase, clarity expectations are high due to rarity; eye-clean stones are exceptional. In mineral specimens, aesthetics and crystal integrity matter more than strict clarity, with undamaged terminations and vivid color being key.

When cut, dioptase is typically fashioned into small step or brilliant cuts, but cutting is risky due to perfect cleavage and brittleness. Any chipping, poor symmetry or dull polish strongly reduces value, so very few cutters attempt it.

Dioptase occurs in copper deposits in Namibia, the Democratic Republic of Congo, Kazakhstan and a few other localities. Crystals suitable for top-grade specimens are limited and often come from a small number of famous mines.

Demand is driven almost entirely by the mineral collecting community, where fine dioptase specimens are highly prized for their intense color. The gem market demand is niche, focusing on collectors of ultra-rare faceted stones.

Prices for top-quality dioptase specimens have increased as classic localities mature and fewer new world-class pockets are found. Faceted dioptase remains a curiosity whose market is too small to show broad price trends.