Tanzanite is a trade name that was first used by Tiffany and Company for gem-quality specimens of a mineral named zoisite with a blue color. Tiffany could have sold the material under the mineralogical name of “blue zoisite,” but they thought the name “tanzanite” would stimulate customer interest and be easier to market.

The name “tanzanite” was given because the world’s only known tanzanite deposit of commercial importance is in northern Tanzania. The name reflects the gem’s limited geographic origin. The mines are all located in an area of about eight square miles in the Merelani Hills, near the base of Mount Kilimanjaro and the city of Arusha.

Faceted blue tanzanite: This violetish blue tanzanite is an exceptional faceted oval weighing 8.14 carats and measuring 14.4 x 10.5 x 7.6 millimeters in size. On the basis of its color and clarity, it would be rated in the top 1% of all tanzanite ever produced. It is easy to see why Tiffany’s called tanzanite “the most beautiful blue stone to be discovered in 2000 years.” Stones of this quality might be purchased by museums, investors, or collectors, or used in custom or designer jewelry.