Tanzanite & Zoisite

What is tanzanite?

Tanzanite is a variety of the zoisite mineral, exhibiting shades of purple, violet, and blue. Other shades of zoisites include yellow, green, and orange, in varying saturation and hues.

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Tanzanite is found in one location, having formed 585 million years ago by significant tectonic activity and heat in the area that would later become Mount Kilimanjaro in Tanzania.

Only recently discovered in 1967, when a Masai tribesman stumbled upon a stone that he believed to be a sapphire in northern Tanzania. Further inspection by a local prospector, Manuel d’Souza, concluded it was not sapphire, but a new, previously undiscovered gemstone. Tiffany & Co. would lay claim as the sole distributor of the stone, naming it Tanzanite as a tribute to its country of origin. Though they are no longer the sole distributors, their association and marketing helped elevate this gem in status.

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The mining area in the Merelani Hills at the base of Kilimanjaro is only 6km long and 2km wide. Having been divided up by the Government into six blocks, the D block often produces the finest gem material and fetches higher prices, although it is somewhat difficult to confirm which block a gem originated from.

Is tanzanite hard-wearing?

Large specimens can be found and are relatively free from inclusions; however, it is less hard than some other gems and can be easily abraded, so care is needed when wearing tanzanite.