The Discovery
The actual discovery of tanzanite remains something of a mystery. Although like any African myth, there are numerous versions. The most widely accredited narrative suggests that in July of 1967, Ali Juuyawatu, a local Maasai tribesman, found a piece of translucent crystal near Mount Kilimanjaro. Fascinated by its blue-violet hue, he shared his find with Manuel D'Souza, a tailor by profession and prospector by passion, who was looking for rubies in the region. Believing the find to be vibrant sapphire, D'Souza had no idea he had stumbled on an entirely new specimen. Gemological tests revealed that the crystal had a composition more complex than sapphire, and that its color was more intriguing, more alluring, and more exotic than any other gemstone.

Mining History
As word of the discovery of the exquisite new gemstone became public, prospectors and tribesmen began to lay claim to the mining areas. Between 1967 and 1972, an estimated two million carats of gem quality tanzanite was produced from open-cast mining operations.

In 1971, the tanzanite mines were nationalised and mining was taken over by the State Mining Corporation, STAMICO. Production records for the first five years indicate a decrease in grades, mainly attributed to haphazard mining and theft. During 1978, Tanzanian Gemstone Industries, a state organisation established by STAMICO, published a report recommending the viability of full scale mining of gemstones. No meaningful action was taken. During the next ten years, production decreased. There was also an increase in informal, artisanal mining. By 1989, an estimated 30,000 artisanal miners were working in the area.

In 1990, the Tanzanian Government curbed artisanal mining and demarcated the area into Blocks A, B, C and D. Block A was awarded to Kilimanjaro Mines Limited, Blocks B and D to small-scale miners and Block C to Graphtan Limited, a graphite mining company. Graphtan ceased mining activities in 1996 and Afgem acquired the mining licence for Block C. In 2000, Afgem completed a feasibility study for the commercial mining of tanzanite and mine development commenced in 2001. In 2004, the TanzaniteOne Group acquired Afgem's tanzanite business and assets.