Prasiolite can also be found spelled praziolite. Prasiolite can be confused with the similarly colored praseolite which results from the heat treatment of iolite, a variety of cordierite.
It is a rare stone in nature. Most prasiolite sold is used in jewellery settings. Prasiolite is heat treated amethyst. Most amethyst will turn yellow or orange when heated producing citrine. But some amethyst will turn green when treated. Currently most all prasiolite on the market results from a combination of heat treatment and ionizing radiation.
Green quartz is sometimes incorrectly called green amethyst, which is an actual misnomer and not an acceptable name for the material, the proper terminology being Prasiolite. It is actually against Federal Trade Commission Guidelines to call prasiolite "green amethyst." Other names for green quartz are vermarine, greened amethyst, or lime citrine.
The name is derived from Greek πράσον prason meaning "leek" and λίθος lithos meaning "stone." This means that "prasiolite" literally means "scallion green-colored stone." The mineral was given its name due to its green-colored appearance.