The Letlhakane mine is a kimberlite open-pit and underground diamond mine in north-central Botswana, located approximately 25 kilometres east of Orapa and operated by Debswana Diamond Company - the joint venture between De Beers and the Government of Botswana that controls all four of Botswana's principal diamond mines. Letlhakane was the first kimberlite mine to be developed in Botswana after the country's independence and was the smallest and oldest of the Debswana operations until its 2017 transition from open-pit to a tailings retreatment operation.

History

The Letlhakane kimberlite pipes were discovered by De Beers prospectors in 1969, four years after the discovery of the giant Orapa pipe in the same general area. Three pipes - DK1, DK2 and a smaller third - were identified, and after technical and feasibility evaluation through the early 1970s the mine entered production in 1977. The Letlhakane mine was a small operation by Botswana standards, producing approximately 1 million carats per year at peak, but it was strategically important as the second Botswana kimberlite mine and as a testbed for Debswana's expansion through the 1980s and 1990s into Jwaneng (1982) and Damtshaa (2003).

Production and stone characteristics

Letlhakane diamonds are generally smaller than those of Orapa and Jwaneng - average stone size and grade have historically been below the Botswana average - but the proportion of higher-quality material has been strong, and Letlhakane has produced several notable individual stones over the years. The mine's by-product (heavy mineral) suite has also been studied as a reference for kimberlite geochemistry in the region.

In 2017, Debswana ceased open-pit mining at Letlhakane and transitioned the operation to a Tailings Resource Treatment plant, which retreats the tailings dumps accumulated over four decades of mining for residual diamond content. This extends the operating life of the Letlhakane site without further open-pit excavation and is consistent with industry-wide trends toward tailings retreatment as primary kimberlite reserves deplete. The TRT plant is expected to operate for at least two more decades on currently estimated tailings inventory.

Position in the Botswana operation

Letlhakane has always been the smallest of the Debswana operations and contributes a relatively modest share of Botswana's overall production, which is dominated by Jwaneng (the world's most valuable diamond mine by carat value) and Orapa. The mine's significance is as much historical as economic: it was Botswana's second kimberlite mine, demonstrated that the country had multiple economically viable kimberlite pipes, and supported the early expansion of Debswana that has made Botswana the world's largest diamond producer by value. The Damtshaa mine, immediately adjacent to Letlhakane, was developed in 2003 to extend operations on smaller satellite pipes in the same area.