Thumbnail Emerald-Green Dioptase Crystals - Kazakhstan

This is a thumbnail sized specimen of gemmy, emerald green Dioptase crystals from the Altyn-Tyube Deposit in Kazakhstan. The crystals have a saturated, dark green color with well defined crystals.

The Altyn-Tyube deposits are the type locality for dioptase, which was first described in the nineteenth century. This remote locality in the Steppes of Kazakhstan has been mined for copper for thousands of years. Dioptase is an intense, emerald-green, copper based mineral which forms small rhombohedral crystals, usually less than 0.75 cm in size.

Dioptase is an uncommon mineral found mostly in desert regions where it forms as a secondary mineral in the oxidized zone of copper sulfide mineral deposits. It is popular with mineral collectors due to it's vibrant color and it is occasionally cut into small emerald-like gems.