Buying Guide

The Gemstone Guide to Tanzanite

About Tanzanite

Loved for
The intense deep purple blue stones are the most highly prized, and rare, shade of this precious gem.

About Tanzanite
Tanzanite was discovered in 1967 in the foothills of Mount Kilamanjaro, and is name after Tanzania, its country of origin.

Brought to prominence by Tiffany & Co. in 1968, a year after it was discovered, the stone is 1,000 times more rare than a diamond. Ethnical tanzanite miners TanzaniteOne mine operate a space only 17 kilometres square, and expected to be depleted within 30 years.

Its rarity gives this stone precious gems status amongst many in the industry.

Colour
Tanzanite is blue zoisite, a calcium aluminum silicate. Although it is found in shades of yellow and green, the deep purple – ultramarine blue hues are by far the most highly prized.

The vast majority of these stones are heat treated to amplify the striking violet-blue colour. It is pleochroistic, which gives the stone its colour-shifting properties when viewed from different perspectives.

Where it's found
Tanzanite is rare, with only one source, the Merelani Hills in Tanzania, East Africa.

Moh hardness
6-7 (1 soft to 10 hard)

Birthstone
For December

Anniversaries
24th wedding anniversary