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
Gahcho Kue Diamond Mine Gahcho Kue Diamond Mine The Gahcho Kué Diamond Mine is located on the Canadian tundra in the Northwest Territories. It is situated at Kennady Lake (), in the Akaitcho Treaty 8 Territory AK claim block, which is southeast of the Snap Lake Diamond Mine and approximately east northeast of Yellowknife. The site is served by Gahcho Kue Aerodrome, which has both an ice runway in winter and a year-round gravel runway, and a spur of the Tibbitt to Contwoyto Winter Road from Lupin Mine. the main camp is at , north of the ice strip, with a smaller site at