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
Luarica diamond mine Luarica diamond mine The Luarica diamond mine is a diamond mine located in Angola. The mine is owned by a consortium of diamond mining companies, the two largest holders being Endiama with 38 percent ownership and Trans Hex with 32 percent ownership. In 2004, the Luarica mine produced about 95,000 carats (19 kg) of diamond from over 632,000 cubic meters of ore processed. 84,000 carats (16.8 kg) of the production was sold in 2004, at an average price of over US$300 per carat (1500 $/g), a new high mark for Angolan diamond production. Probable reserves are 1.3 million cubic meters