| Quartz | |
|---|---|
Raw natural prasiolite |
|
| General | |
| Category | Oxide mineral |
| Identification | |
| Color | shades of green |
| Mohs scale hardness | 7 – lower in impure varieties |
| Diaphaneity | Transparent to nearly opaque |
Prasiolite, green-quartz or vermarine is a green form of quartz, a silicate mineral chemically silicon dioxide. Prasiolite is one of several quartz varieties. Since 1950, almost all natural prasiolite has come from a small Brazilian mine, but it is also seen in Lower Silesia in Poland. Naturally occurring prasiolite is also found in the Thunder Bay area of Canada.[1]
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.[2]
It is a rare stone in nature. Most prasiolite sold is used in jewellery settings. Prasiolite is heat treated amethyst.[1] 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 cobalt-60 or E-beam irradiation.
The name is derived from Greek πράσον prason meaning "leek" and λίθος lithos meaning "stone." This means that "prasiolite" literally means "garlic green-colored stone." The mineral was given its name due to its green-colored appearance.