Tanzanite
The violet-blue gemstone from the foothills of Mt. Kilimanjaro...also known as Zoisite

Tanzanite is another gem that was discovered in the 1960’s in East Africa.
It is found in Merelani, Tanzania, which is by the foothills of Mt. Kilimanjaro, Africa’s highest mountain at 19,341ft above sea level.
Tanzanite is the gem form of the mineral zoisite and is trichroic in its natural, unheated state, meaning that each axis of the crystal displays a different color.
The stones are then usually heated to remove the brownish components, leaving the blue and violet-purples visible.
Tanzanite is one of the birthstone choices for December and celebrates the 24th Anniversary.
We have many more shapes and sizes available in Tanzanite – please contact us if you don’t find what you are looking for in our online inventory.
Here is a link to GIA’s Buyer’s Guide to Sapphires:
click here to see a selection of Tanzanite for sale
Colors | violet-blue blue purple purple-blue |
Family/Species | Zoisite |
Properties | RI = 1.691-1.704 DR SG = 3.30 (+/-0.10) Hardness = 6-7 suitable for use in jewelry but not recommended for rings that will be used frequently or that have unprotected settings |
Treatments | Almost always enhanced by heat, but we do have Natural, unheated material available too See policy on Treatment Disclosure |
Important information | Smaller stones of intense color are rarer than larger stones of the same color note: ultrasonic cleaners can harm stones |
Birthstone | December |
Anniversary | 24th |
Cuts | Free sizes and Calibrated in standard cuts |
Mining locations | Merelani, Northern Tanzania, and as a secondary product of Tsavorite mining in Southern Kenya |