dioptase

Dioptase, a captivating gemstone with its name derived from the Greek words "dia" (through) and "optima" (vision), alludes to its stunning green colour and visual allure. This rare gem is composed of copper silicate and is renowned for its vibrant emerald-like hue.

Dioptase is primarily found in desert regions with copper deposits, including Kazakhstan, Namibia, and parts of the southwestern United States. Its formation typically occurs in the oxidized zones of copper ore deposits, where it develops into exquisite green crystals.

One of Dioptase's most captivating attributes is its remarkable transparency, allowing light to create a mesmerizing play of colour within its depths. Due to its relative scarcity, Dioptase is highly sought after by gemstone collectors and jewellery enthusiasts, adding a unique and vivid touch of green to the world of gemstones.

Click on the terms in the table below to discover their meaning

Click on the terms in the table below to discover their meaning

Name Dioptase
Category Cyclosilicate
Chemical Formula CuSiO3 · H2O
IMA Symbol Dpt
Crystal System Trigonal
Crystal Habit Commonly in prismatic to rhombohedral crystals; as indistinct crystalline aggregates and massive
Twinning Uncommon contact twins or penetration twins
Cleavage Perfect
Fracture Conchoidal to uneven
Tenacity Brittle
Hardness
(Moh's Scale)		 5
Specific Gravity 3.28 - 3.15
Diaphaneity Transparent to translucent
Colour Emerald-green, blue-green
Streak Green
Lustre Vitreous
Optical Class Uniaxial (+)
Refractive index nω = 1.652 - 1.658
nϵ = 1.704 - 1.710
Birefringence δ = 0.052
Dispersion Rd = 0.030
Pleochroism Weak
Clarity Type III
Notable Varieties Dioptase

References

Mineralogical Society of America. (2018). Dioptase. In J. W. Anthony, R. A. Bideaux, K. W. Bladh, & M. C. Nichols (Eds.), Handbook of Mineralogy. Chantilly, VA 20151-1110, USA: Mineralogical Society of America. Retrieved from https://www.handbookofmineralogy.org/pdfs/dioptase.pdf

The Gemology Project. (2007, January 10). Dioptase. Retrieved from The Gemology Project: http://gemologyproject.com/wiki/index.php?title=Dioptase

About the Author

Daniel Gillespie is student of Web Development and the developer of Gemology 101. With a straightforward and informative approach, Daniel invites readers to explore the world of gemology, offering a valuable resource for both enthusiasts and those seeking knowledge about precious stones.