A Geoscience Digital Image Library

DescriptionDioptase is a hydrated copper silicate with the chemical formula CuSiO3-H2O. It's color can challenge the green of emeralds, but the mineral is too soft to cut as a gemstone. Specimens of dioptase are often deeply colored and show well developed crystals. Dioptase is one of the few silicates to crystallize in the same symmetry class as dolomite and forms crystals that can have a typical carbonates' rhombohedral shape. Dioptase forms as a secondary mineral in oxidized zones of copper deposits. Dioptase is relatively abundant but demand may put a stress on dioptase supplies. Dioptase's name comes from the Greek, dia meaning “through” and optomai meaning “vision”. This sample is approximately 3 cm.
LocationUSA ▹ Arizona. Near Tiger.
PhotographerShannon Heinle. 2002-01-22.
CollectionUniversity of North Dakota Mineralogy Collection #3043.
Key wordsdioptase, silicate, rhombohedral
Tech details146 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens.
GeoDIL number2170