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 chairman. In 2004 the mine had 955 employees and recovered 7,187,300 carats (1437.5 kg) of diamonds from 5,871,000 metric tons of ore. The Kolope River flows 8 km to the west of the mine. Surface water storage dams have been built on two of its tributaries. 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