This is the green variety of spodurnene, which has only been known tor about a century and is named after A_E Hidden, a mine-owner in the United States. where the mineral was first discovered. Some people nowadays maintain that the name hiddenite refers only to the emerald green or rich green variety ot spodumene, whereas others appiy this name to all gem-quality green spodumene, including pale and yellowish-green specimens; this seems the most practical definition.

Appearance The best. and very rare, specimens are a bright, almost emerald green, with quite strong green to blue~green pieochroism; but hiddenite may be a rather dull, pale green or even green with a yellowish tinge. The step cut is the most common. Strongly colored stones are usually small to medium—sized; paler specimens are often a bit bigger. but never as large as kunzite.

Distinctive features It is hard to generalize about a gem of such rarity and diverse appearance. Depending on the specimen. hicldenite may resemble both pale and strong colored emeralds, bright green and yellowish tourmalines, chrysoberyl, and diopside. The physical characteristics always have to be measured in order to identity it.

Occurrence The finest gems used to come from North Carolina. The less attractive, paler types, perhaps with a yellowish tinge, come from California, Brazil, and Madagascar.

Value Its attractive color, rarity, and the difficulty of finding reasonable—sized stones make intensely colored hiddenite one of the most valuable secondary gems.

Paler—colored specimens, which are easier to find in a good size, are of quite low value, similar to that of kunzite.

Simulants and synthetics Being little known and of recent history, hiddenite is not imitated. Nor is it produced synthetically, at any rate not on a commercial scale. Yet large stones, in which the medium-light green color is due to some form of treatment (probably irradiation) of very pale or colorless stones, or even very pale kunzite, do appear on the market from time to time.