Tanzania starts survey of tanzanite belt in Mirerani

Tuesday 10th November 2026

By inAfrika Newsroom

Tanzania has begun surveying 636 square kilometres in and around Mirerani to see whether the rock structures associated with tanzanite continue beyond the controlled mining area. Minerals Minister Anthony Mavunde launched the work on 9 November, following an August visit to the area.

The Ministry of Minerals said the Geological Survey of Tanzania will use magnetic, electrical and electromagnetic measurements to identify structures worth examining. The State Mining Corporation, known as STAMICO, will then drill selected targets to check what the rocks contain.

The survey covers ground on both sides of the controlled area. Geological Survey chief executive Ally Samaje said a review of existing and newer geological data had already identified structures that needed closer study, Jambo FM reported.

The measurements help geologists decide where to drill by showing how rock properties vary underground. The presence of tanzanite outside the established workings will need to be tested by drilling.

The Geological Survey said in August that the programme formed part of a government policy to set aside 10% of mining-sector revenue for detailed exploration. Mavunde said on 9 November that the data should help small-scale miners identify areas worth investigating.

Mavunde also directed the survey agency to continue investigating green garnet and tsavorite around Lemshuku, a separate area in Simanjiro District where those stones are already mined.

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