Green Amethyst (Prasiolite) FAQ
(Learn more about the mineral "Green Amethyst", also called Prasiolite/Praziolite, Amagreen or Vermarine.)
What is Green Amethyst?
Green Amethyst, is a light to medium green member of the Quartz species of minerals. Other members of the Quartz family used as gemstones include Smoky quartz, rose (pink) quartz, citrine, lemon quartz and amethyst (lavender).
Green amethyst is NOT related to any of the other popular green gemstones - emerald (green beryl), tourmaline, tsavorite garnet, chrome diopside or peridot (olivine).
Are there other names for Green Amethyst?
Green amethyst is a mineral of many names! A geologist would tell you that this gem stone is more properly called greened amethyst or prasiolite (sometimes spelled praziolite). The word "Prasiolite" comes from the Greek words meaning "Leek Stone". It is also known as Green Quartz or (incorrectly) called lime citrine. Less common names for the mineral are Vermarine and Amagreen.
Why are Green Amethysts Green?
Green amethyst is produced when heat is applied to a certain type of amethyst. Most amethyst turns yellow, orange or brown when heated, but amethyst containing iron compounds with specific properties (Fe2+ iron compounds) will turn green instead.
Some natural sources green quartz has been found, however the green amethyst sold as gemstones is heat-treated. The two are the same - it is speculated that heat produced naturally by geological events during formation of the mineral caused the production of the naturally green deposits.
What are the mineral properties of Prasiolite?
Prasiolite, like all Quartz, is composed of silicon dioxide (SiO2). It forms hexagonal crystals, has a hardness of 7 on the Mohs scale, and a specific gravity (a measure of a stone's weight in proportion to its size) of 2.65. It contains a specific type of iron compound which changes to a green color when heated (see above) - either by naturally occurring or manual application of heat.
Natural prasiolite crystlas are reported to often be dichroic - this means they appear as different colors when observed under lights with differing polarizations.
Where is Prasiolite Found?
The type of amethyst from which green amethyst is made is found in only a few locations, the main source being Brazil - particularly in Montezuma (Minas Gerais state). Other locations where this variety of amethyst have been found include Arizona, the California-Nevada border, and Zimbabwe.
Deposits of naturally occurring prasiolite (green amethyst) has been reported in Southern Bahia (Brazil), Canada (Thunder Bay), Poland, Tanzania, Namibia, Nevada and New Hampshire. It is often to be found side-by-side with purple amethyst crystals in igneous, metamorphic and volcanic rock.
Is Prasiolite Suitable for Making Jewelry?
Yes! Prasiolite, like ordinary amethyst, citrine and smoky quartz, is a wonderful gemstone for jewelry. It is durable and scratch-resistant enough for daily wear in rings, pendants, bracelete or earrings, and the large crystals make it perfect for spectacular large-carat gemstone jewelry in cushion, emerald, pear shape, trillion, or other popular cuts.