Prasiolite
Prasiolite is transparent green macrocrystalline quartz. It is the precise gem name for the material commonly sold to shoppers as “green amethyst.”
Quick facts
| Mineral | Quartz |
|---|---|
| Common shopping name | Green amethyst |
| Typical appearance | Pale green, mint, yellow-green, grey-green or leek-green |
| Mohs hardness | About 7 |
| Commercial colour | Often produced by treatment of suitable quartz material |
Why the name matters
Using prasiolite helps separate the identity of the stone from claims about how its colour formed. A seller can correctly identify a stone as prasiolite and still need to disclose relevant treatment information.
Treatment and natural colour
Naturally green prasiolite exists, but most material in ordinary jewelry trade is treatment-produced. Heat and irradiation can create green colour in suitable quartz. Appearance alone is not a reliable way to prove untreated natural colour.
What it looks like
Prasiolite is usually much softer-looking in colour than emerald or vivid green tourmaline. Because the colour is often pale, cut quality and lighting can strongly affect how lively or washed out the stone appears.
Related terms
Quartz, amethyst, heat treatment, irradiation, carat, windowing and extinction.