Tanzanite is the blue to violet gem variety of the mineral Zoisite. Since its relatively recent discovery in 1967, it has become a mainstream and popular gemstone, and is used extensively in jewelry. To date, Tanzanite is found only in the Arusha region of the African country of Tanzania, and it was named after its country of origin. 

Tanzanite gemstones are always Heat treated. Natural Tanzanites have a more dull gray, greenish, or brownish color, and heating to above 800 degrees Fahrenheit (about 430 Celsius) will produce the deep blue to violet color. The main appeal of Tanzanite is its lovely color. Its color ranges from pure blue to purplish-blue. It is highly pleochroic, and will display different color saturation when viewed at different angles.