Chemical composition -- Lithium aluminum silicate.
Color-- colorless, yellow, pink, violet, blue, green.
Optics -- R.I. 1.66-1.68, biaxial positive.
Durability -- Hardness 6.5-7.5. Brittle, with one direction of perfect cleavage that makes faceting difficult. Stones should not be worn in jewelry subject to heavy wear.
Crystal structure-- Monoclinic.
Specific Gravity-- 3.0-3.2.
Sources -- Brazil, Afghanistan, North Carolina.
Varieties -- kunzite, hiddenite.
A medium-deep green spodumene found only in Hiddenite, North Carolina. Both the town and the gem are named after William Hidden, the original mine owner. Hiddenite occurs only in small crystals and is quite rare. Ordinary green spodumene from other localities is often erroneously and misleadingly labeled hiddenite, which must contain chromium to deserve the name.
A violet-pink spodumene, usually quite pale but sometimes bright and intense. The color is somewhat unstable and tends to fade in sunlight. The best material comes from Madagascar, Afghanistan, and Brazil. Large pieces are fairly abundant.