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
Venetia Diamond Mine Venetia Diamond Mine The Venetia Diamond Mine is South Africa's largest producer of diamonds. It is situated close to the South African town of Alldays in the Limpopo province and is located within the 360 km² Venetia Limpopo Nature Reserve. The open-pit mine is one of De Beers’ six remaining diamond mines in South Africa and the only major diamond mine to be developed in the country during the past 25 years. As such, the mine represents one of De Beers’ single biggest investments in South Africa. The mine was opened in 1992 by Harry Oppenheimer, a former De Beers