Hiddenite is the strongly pleochroic, bright green variety of spodumene. First discovered in North Caroline by W. E. Hidden in 1879.

Gemological information

Gemological Information for Hiddenite
Color Green
Crystal Structure Monoclinic
Refractive Index 1.662 to 1.676
Durability Poor
Hardness 6.5 to 7
Similar Stones Tourmaline, Peridot, Beryl
Treatments Irradiation
Country of Origin Afghanistan, Madagascar
Hiddenite Care
Ultrasonic Cleaning Never
Steam Cleaning Never
Warm Soapy Water Safe
Chemical Attack Reacts slowly to Hydrofluoric Acid
Light Sensitivity Irradiated Green fades quickly
Heat Sensitivity Sensitive


Gem Reference Guide, Los Angeles: Gemological Institute of America, 1988. Pp. 229-231.

Newman, Harold. An Illustrated Dictionary of Jewelry, New York: Thames and Hudson, 1981. Pp. 154-155.

Schumann, Walter. Gemstones of the World, New York: Sterling Publishing, Co., 1977. Pp. 114.