Green amethyst terminology
Short definitions for the words you are most likely to see in gemstone listings and guides.
Transparent green quartz; the precise gemstone name for material commonly sold as green amethyst. Full definition.
A familiar retail name for prasiolite. It does not by itself say whether the colour is natural or treatment-produced.
The mineral family that includes amethyst, citrine, rock crystal and prasiolite.
Purple quartz. Some amethyst can produce green material after carefully controlled treatment.
Controlled heating used to change or develop colour in suitable gemstone material.
Exposure to radiation under controlled conditions to alter colour centres in suitable material.
A claim that the visible colour developed without human treatment. If it carries a large premium, ask what supports the claim.
A unit of gemstone weight. One carat equals 0.2 grams; it is not a measurement of visible diameter.
A see-through area in a faceted stone where light leaks through instead of returning toward the viewer.
Broad dark areas that return little visible light from the viewing angle.
How large the stone appears when viewed from the top, usually understood from millimetre dimensions.
A different material made or presented to look like another gemstone, such as green glass sold to resemble prasiolite.