What is Fancy Colour Tanzanite?

28th March 2017 | 2 min read Share This Story:

You may already be familiar with Tanzanite. Mined in one small area near Arusha in Northern Tanzania, it was discovered 50 years ago this year. This pinkish blue gemstone is one of the rarest gemstones on the planet. It is thought to be 1000 times rarer than Diamond. But did you know there are other colours of Tanzanite mined which are even rarer?

Technically known as 'Fancy Zoisite' by gemologists, these unusually-coloured Tanzanites make up less than 10% of all Tanzanite mined. This means that they are thought to be around 10,000 times rarer than a diamond.

The fancy colour you are most likely to come across is a greenish-blue. Trade names for these extraordinary gems include 'Bi-Coloured', 'Chameleon', 'Peacock', or 'Ocean' Tanzanite. You will sometimes find colours that are similar to a peacock feather – a mixture of blues, greens, and purplish-pinks. You may also come across Tanzanites that are much more green than blue.

Shop Bi-Colour Tanzanite.

Are these colours natural?

Almost all Tanzanite is heat treated. Be extremely wary of anyone who tells you that their Tanzanite is natural, unless they have supporting documentation. However, Fancy Colour Tanzanite undergoes the same process as Blue Tanzanite, but comes out a different colour. These stones are coloured the way they are due to a rare difference in chemical composition, rather than it being linked to heating. Those that show green have more chromium and less vanadium than the majority of Tanzanites. It is possible to find pieces that show a clear distinction between a greener form of Tanzanite and the blue form within one gemstone as a 'split' – but these are exceptionally rare.

Are there other colours?

The most prized Tanzanite of all and those that tend to command the highest prices of all, are those which display yellow, champagne, or pink colours. These are the rarest of all, and are the most highly prized.