Blue lightning

Bling bling. Diamonds may be a girl’s best friend, but tanzanites, which are more than a thousand times rarer, and not from a conflict area, are increasingly sought after. Formed beneath our planet’s surface almost 600 million years ago, tanzanite is found in only one place on Earth – in the foothills of Mount Kilimanjaro. According to experts, the chances of tanzanite occurring elsewhere in the world in one in a million. Over the next couple of decades, all the existing tanzanite is likely to be mined and purchased, meaning that in the future it will be a heirloom gem.

There are many Maasai legends about its creation. One says that the land was set ablaze by a bolt of lightning and the heat transformed the ground into crystals. Certainly, the discovery of the stone is ascribed to a local Maasai tribesman, Ali Juuyawatu, in 1967. Word about the discovery of tanzanite soon reached famous New York jewellers Tiffany & Co. Henry B Platt, great grandson of company founder Louis Comfort Tiffany, and later chairman of the firm, was fascinated by this new gemstone. He named it ‘tanzanite’, rather than its mineral name ‘blue zoisite’, and launched it at Tiffany’s in October 1968, claiming it was ‘the most beautiful blue stone discovered in over 2000 years’.

Tanzanite is ‘trichroic’, which means that it radiates three difference colours from each of its crystallographic axes – blue, violet and bronze. In the ground the bronze colour is more dominant, but gentle heating brings out the richer blues and violets. The colour of a tanzanite stone at a glance can vary hugely – from royal blue to lilac, periwinkle to indigo. Tanzanite has a similar hardness to an emerald but is less brittle, however it is not as tough as a diamond. Tanzanite jewellery is really occasionwear rather than for an everyday stone.

The quality of a stone is decided by the ‘four Cs’ – colour, clarity, cut and carat weight. You can also choose whether to buy an unset stone or a piece of readymade tanzanite jewellery.

On a more sober note, tanzanite mining – like any mining – is a dirty and dangerous business. But gemologists Guillaume Soubiraa and Michael Rogers, who visited some of the deepest working tanzanite mines, maintain that for all the hardship, toil and risk faced by these miners, the best that you can do is to reward their toil by buying the end product.

On their blog at www.ruby-sapphire.com, they write: “Having experienced firsthand the conditions under which tanzanite is mined gives us a new-found respect. No longer when we view tanzanite do we do simply see a blue stone. Instead, when gazing into its azure depths we see the soldiers who work the blue seam. While some might see them singing the blues, we now hear their song, we look towards their mistress. Her name is Hope.”

Want to know more about tanzanites or buy a stone to become a future family heirloom?

In Arusha you can visit museum The Tanzanite Experience to find out more about the stone, or you can even visit TanzaniteOne’s mine, 70km from Arusha, for a guided underground mineshaft tour.

In Zanzibar, stockists of tanzanite include:

Memories of Zanzibar, Kenyatta Street 024 223 9376/7

La Opala, Kenyatta Street 024 223 8058 or 0777 414686 or 0762 414686 http://www.laopalajewellers.com/