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 of ore at an ore grade of per 100 cubic meters (43.2 mg/m³). There is a waste rock overburden of about 9.5 million cubic meters. Mining operations were suspended in May 2009 due to a decline in diamond demand caused by the late-2000s financial crisis. Trans Hex announced in August 2011 that it planned to withdraw from its two Angola joint-ventures with Endiama—Luarica and Fucauma—after failing to reach an agreement with the government of Angola (which owns the other major partner, Endiama). Endiama stated that it planned to restart operations alone. Luarica diamond mine The Luarica diamond mine is a