Argyle diamond mine at the Ekati mine, both in Canada. However, Argyle has two to four times the concentration of diamonds (ore grade) of these mines. This makes extraction economically feasible, as mine costs are mostly related to the amount of ore processed, not the amount of diamond extracted. In 2005, Rio Tinto was given the go-ahead to a future expansion project, moving it from an open pit to an underground mine. This plan was postponed; in September 2010 Rio Tinto announced fresh plans to develop an underground mine beneath the existing pit, increasing annual production to 9 million tonnes of ore. The
Damtshaa diamond mine Damtshaa diamond mine The Damtshaa diamond mine is a diamond mine located in Botswana about west of the city of Francistown. Damtshaa, meaning "water for a tortoise", is owned by Debswana, a partnership between the De Beers company and the government of Botswana. It is the newest of four mines operated by the company, officially opening on October 25, 2003. Damtshaa is of open pit construction, located on top of four distinct kimberlite pipes of varying ore grade. The mine is forecast to produce about 5 million carats (1,000 kg) of diamond from 39 million tons of ore over the