Skip to content
Mineralati

Minerals

Dioptase

dioptase

CuSiO3·H2O

Dioptase Crystal - A Bluish-Green Copper Cyclosilicate Mineral

Dioptase Crystal - A Bluish-Green Copper Cyclosilicate Mineral — via www.grimballjewelers.com · Source

Overview

Dioptase is an intense emerald-green to bluish-green mineral that is cyclosilicate of copper. It is transparent to translucent. Its luster is vitreous to sub-adamantine. Its formula is Cu6Si6O18·6H2O, also reported as CuSiO2(OH)2. It has a Mohs hardness of 5, the same as tooth enamel. Its specific gravity is 3.28–3.35, and it has two perfect and one very good cleavage directions. Additionally, dioptase is very fragile, and specimens must be handled with great care. It is a trigonal mineral, forming six-sided crystals that are terminated by rhombohedra. It is popular with mineral collectors and is sometimes cut into small gems. It can also be pulverized and used as a pigment for painting.

Identification characteristics

  • Mohs hardness 5

Scientific references

  1. Dioptase — Wikidata. https://www.wikidata.org/wiki/Q413369 Link
  2. Dioptase — Wikipedia. https://en.wikipedia.org/wiki/Dioptase Link