Tanzanite

Tanzanite is the blue/purple variety of the mineral zoisite. The gemstone is strongly trichroic, meaning it can appear sapphire blue, violet and burgundy depending on crystal orientation.

Tanzanite is usually a reddish brown in its rough state, requiring artificial heat treatment to bring out the blue violet. The mineral was named by Tiffany & Co.. after Tanzania, the country in which it was discovered. In 2002, The American Gem Trade Association chose Tanzanite as a December birthstone. It is 6.5 on the Mohs scale.