Prasiolite is light mint green quartz, the brother of amethyst and citrine.  It is also sometimes incorrectly referred to as “Green Amethyst” . Prasiolite is the result of an amethyst (purple quartz) gemstone being exposed to high heat.  This process can occur naturally inside the earth, or by humans in a laboratory.  Not every amethyst will produce prasiolite when heated (some will turn into citrine).  Prasiolite that is not treated is very rare and most of it comes from one mine in Brazil.

Prasiolite, like almost all quartz, can be found in very large sizes.  Its range of clarity is similar to that of amethyst and very clear stones are not hard to find.  The most important factor in determining the value of a piece of prasiolite is its color – the richer, more saturated green, the better.  However, by its nature, prasiolite will never be dark. In fact, a lot of lab-grown quartz is sold unscrupulously (e.g. on ebay) as prasiolite.  If it is very dark or rich in color, stay away.

Typical: This is a very nice prasiolite, of the quality that you would expect to find in a fine jewelry store Pale color:  This prasiolite is very pale.  You see a slight flash of minty color and a lot of reflection of the objects around it – it is mostly a colorless stone. The best:  You really don’t see prasiolite this color very often – usually only a few here and there and only in the finest jewelry stores.  This one, in a ring of gold and diamonds, sold for $18,000. Fake:  Any gem this color that is sold as prasiolite is an imposter.  No quartz occurs this color naturally, but it is the easiest thing to grow in a lab.


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