Discovery of tanzanite (blue zoisite)
Descubrimiento de la tanzanita (zoisita azul)
- Date
- 1967 · confidence high
- Place
- Mererani, Simanjiro, Manyara, Tanzania
- Credited to
- Local prospectors, with Manuel d'Souza registering the claim
- Field
- Cosmos & Earth
⚠️ Disputed: the sources disagree.
What was discovered
A blue-violet variety of zoisite found in the Mererani hills, the only place in the world where it is mined. Tiffany & Co. launched it in 1968 as 'tanzanite' and made it a jewellery gem.
Accounts of who found it first vary: Ali Juuyawatu, a Maasai herder and the tailor-prospector Manuel d'Souza figure in different versions. The blue colour is due to vanadium and natural heating.
What it led to
- artisanal and large-scale mining in Manyara
- an international market with traceability and labelling
- colour change by heat treatment from brown to blue