Tanzania's Gemstones: Tanzanite and More

Tanzanite: found in only one place

Tanzanite is a blue to violet variety of the mineral zoisite. According to the Gemological Institute of America, its only known source is the Merelani hills in northern Tanzania, on the plains between Arusha and Mount Kilimanjaro. It came to the world's attention in 1967.

Its colour shifts between blue and violet depending on the angle and the light. Most tanzanite is gently heated to bring out the blue, a common and accepted practice; a good seller will tell you whether a stone has been treated.

Other gems from Tanzania

• ›Tsavorite: A vivid green garnet, found in Tanzania and neighbouring Kenya.
• ›Other garnets: Red and pink garnets in many shades, popular in jewellery.
• ›Tourmaline: Green, pink and multicoloured stones.
• ›Spinel: Red, pink and blue spinel, increasingly sought after.
• ›Sapphire and ruby: Including ruby in green zoisite from the Longido area north of Arusha, a striking stone often used for carvings.

See it for yourself

The mining area at Mererani is about 60 km from Arusha, inside a security wall with a single guarded gate, so visits go through a licensed local partner. On our Mererani tanzanite mine tour, you see how miners work and watch stones being cut. For something shorter, the Tanzanite Experience in Arusha is a half-day museum visit with a cutting demonstration.

Buying gems safely

• ›Buy only from licensed dealers, never from people on the street. Fake and glass stones are common.
• ›Look at stones in daylight and ask whether they have been treated.
• ›Keep the receipt, any certificate and the export or tax paperwork the dealer gives you.
• ›Rules on selling and exporting gemstones are set by Tanzania's Ministry of Minerals and can change, so ask the dealer what applies to you.