Tanzanite: a Rare Gemstone from Tanzania Africa
Tanzanite is the blue/purple variety of the mineral zoisite which was discovered in the Mererani Hills of Northern Tanzania in 1967, near the city of Arusha. It is used as a gemstone. Tanzanite is noted for its remarkably strong trichroism, appearing alternately sapphire blue, violet and burgundy depending on crystal orientation.
Tanzanite in its rough state is usually a reddish brown color. It requires artificial heat treatment to 600 °C in a gemological oven to bring out the blue violet of the stone. Tanzanite is a rare gem. It is found mostly in the foothills of Mount Kilimanjaro. The mineral is named after Tanzania, the country in which it was discovered.
Originally called “blue zoisite” it was renamed as part of a campaign by Tiffany & Co., who wanted to capitalize on the rarity of the gem, then only found in Tanzania, but who thought that “blue zoisite” (which might be pronounced like “blue suicide”) wouldn’t sell well. From 1967 to 1972, an estimated two million carats of tanzanite were mined in Tanzania. The mines were later nationalized by the Tanzanian government.
*Some text taken from Wikipedia