Within the species zoisite lies a gemstone of drama and intrigue that’s consider, alongside the sapphire, to be of the finest blue stone in existence. Tanzanite, despite its scarcity, has not only gained a remarkable public awareness in a very short space of time, but has become an object of desire worldwide.

Tanzanite is a rare and beautiful transparent indigo-violet gemstone that is found in just one area of Tanzania and nowhere else. It was first discovered in 1967 and was recognised as a major gemstone when Tiffany & Co. introduced it to the international market. In an industry where colour is increasingly growing in importance for both jewellery makers and buyers alike, the tanzanite provides a more colourful and slightly more affordable option compared to a large blue sapphire.

The tanzanite can appear in a range of colours from a deep sapphire blue to violet-blue to soft lavender and lilacs, all due to the presence of vanadium. They often have a distinct pleochroism, allowing the specific hue of the stone to alternate when viewed from different angles. Occasionally the stone will be heat treated to produce a more intense blue colour. Considering the tanzanite doesn’t have the natural brilliance of a sapphire, it is often faceted into trillion, cushion and brilliant cuts to aid the stones lustre.

Tanzanite stone on workbench
Cabochon cut tanzanite in white gold ring

Judith Crowe, The Jeweller's Directory of Gemstones (London: A&C Black, 2006)
Cally Hall, Gemstones (London: Dorling Kindersley, 1994)
Jaroslaw Bauer and Vladimir Bouska, A Guide in Colour to Precious & Semiprecious Stones (London: Octopus Books, 1983)