Tanzanite is a variety name of the mineral Zoisite and should only be used to describe the purple/blue material from Tanzania.
In its original form, Tanzanite is a dark brownish color, and is then heated to achieve the blue/purple.
Tanzanite was made famous by Tiffany and Co, who was the first to introduce it to the United States. Tanzanite gets its name from the country where it is found; Tanzania.
Tanzania is currently the only location in the world where you can find commercially viable deposits of Tanzanite.
The mineral Zoisite can be found in a number of locations in the world including Europe and North American.
Gem quality Zoisite occurs in the following colors: colorless, blue/purple, grayish-white, grey, yellowish-brown, yellow, pink, green.
At a 6.5-7.0 on the Moh's scale of hardness, Tanzanite is best suited to earrings and pendants.