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
Dominion Diamond Mines Ekati combined are estimated to produce over 7 million carats of diamonds in 2014, worth an estimated $1.1 billion. Diavik and Ekati are currently ranked the 9th and 19th largest diamond mines in the world, respectively, according to total carat production. The company's participation in the retail segment of the diamond pipeline was by means of its ownership of Harry Winston, Inc., a chain of retail stores. On January 14, 2013 the company announced that it has entered into an agreement to sell its luxury brand diamond jewelry and timepiece division, Harry Winston Inc., to The Swatch Group Ltd. for