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
Orapa diamond mine Orapa diamond mine The Orapa diamond mine is the world's largest diamond mine by area. The mine is located in Orapa, a town in the Central District of Botswana about west of the city of Francistown. Orapa ("resting place for lions") is owned by Debswana, a partnership between the De Beers company and the government of Botswana. It is the oldest of four mines operated by the company, having begun operations in July 1971. Orapa is an open pit style of mine and is the largest diamond mine in the world by area. The mine is located on two kimberlite