2.2" Gemmy Dioptase Crystals on Quartz - Sanda Mine, Congo

This is a beautiful cluster of gemmy dioptase crystals on quartz that was collected from the Sanda Hills occurrences (Sanda mine) in the Republic of the Congo. Botryoidal, blue shattuckite formations can be seen beneath the quartz and on the "back side" of the specimen. This mine has been closed since 2019, so this material is old stock. The entire specimen is 2.2" wide and the dioptase is a lustrous, emerald-green color.

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. This copper-based mineral forms small rhombohedral crystals, typically less than 0.75 centimeters in length. It is popular with mineral collectors due to its vibrant color and it is occasionally cut into small emerald-like gems.

Dioptase, Shattuckite & Quartz
Sanda Hills Occurrences, Mindouli, Mindouli District, Pool Department, Republic of the Congo
2.2 x 1.8"