Oh Boy! If I had a dollar for everytime I was asked about this!

If you ever look a blue or purple Tanzanite and the listing tells you that the stone is unheated or untreated.......RUN!!!!!

The rule is very simple, if the stone is not brown to a yellow-brown it has been heated! Yes folks all tanzanite is heated and if someone tells you otherwise they are either dumb as a box of rocks or lying!

I deal in thousands of carats of Tanzanite every year, some fancy colored and a heck of a lot of D Block products. It is very rare to find unheated cut stones, why you ask???? The color looks a lot like baby poop. Once heated to 550 degrees a wonderful thing happens, the color changes. Depending on the depth of brown color you will wind up with blues and purples.

Ask me sometime to send a pic of a unheated round cut stone, I have a 4 ct here and would be glad to share what one looks like!