How To Tell If Tanzanite Has Been Heated

According to my new book, Gemstone Identification Made Easy, there is a fairly simple way to tell if your Tanzanite is natural in color, or has been heat treated. Most Tanzanite comes out of the ground, brown or green color, and then is heat treated to get the various bluish purple colored gemstones. However some Tanzanite comes out of the ground those colors, naturally. Of course these gemstones would have a much greater value, than the heated variety. Plus you may be being charged too much for a stone being sold as natural, when in fact it has been heat treated. The use of a dichroscope, can help you in determining if your stone has been treated or not. Tanzanite is a trichoic gemstone, meaning it shows three different distinct colors. When looking through a dichroscope, you will see three distint different colors. Natural, unheated Tanzanite will show blue, purple, and green. Sometimes the purple color will be reddish, and sometimes yellow instead of green. However the important thing is that you will three distinctive different colors in unheated Tanzanite. The green, yellow coloring is very often not seen in heated Tanzanite. If you view through your dichroscope your Tanzanite, and you see blue, purple, and green chances are good that you have gotten an unheated, natural Tanzanite. Congrats to you, if you have such a rare, and fabulously valuable Tanzanite in your collection.