Dioptase

This fine thumbnail specimen features deep emerald-green dioptase crystals with excellent luster from the type locality, the Altyn-Tyube Dioptase Deposit in Kazakhstan. The name "Altyn-Tyube" translates to "Golden Hill" in Kazakh, and the deposit has been known since Neolithic times for its copper mineralization.

While the specimen has some contacted areas, it remains a highly representative example of both the species and its historically significant locality. Altyn-Tyube is renowned for producing some of the world's finest dioptase crystals, and this piece is a classic from the first known occurrence of the mineral. For more information on this locality, see Mineralogical Record, March-April 2023 (Vol. 54, No. 2).