What is Tanzanite?

Tanzanite as the name suggests is a gemstone from Tanzania close to Mt Kilimanjaro. It is actually a form of zoisite

A rich blue colour it is fairly soft (6/10 mohs) but does have an amazing ability to apparently change colour as you turn it. In a flash it can appear to change from almost red to purple to deep blue depending on the lighting conditions and the angle you are looking at it from.

cut, clarity, and availability all have an effect on price, but in general small gems sell for around £50 per carat and larger sizes above 2 carats sell for about £70 per carat. (Early 2008)