Dominion Diamond Mines Dominion Diamond Mines Dominion Diamond Mines (formerly known as Dominion Diamond Corporation, Harry Winston, and Aber) is a Canadian specialist diamond mining company. The company holds a 40% stake in the Diavik Diamond Mine Project. Production at the Diavik Diamond Mine, Canada's second diamond mine, is operated by Dominion Diamond Mines' joint venture partner, Diavik Diamond Mines Inc., a subsidiary of Rio Tinto Group. The mine began producing diamonds in November 2002. In 2012 the company purchased all of BHP Billiton's diamond assets; the primary asset is the Ekati Diamond Mine, which is adjacent to the Diavik Mine. Diavik and
Argyle diamond mine of the open pit; these reserves would be mined underground (by block caving), rather than the open pit method currently used. In late 2005, Rio Tinto Ltd concluded that the operation was economically feasible. Pre-production construction of the underground mine commenced in early to mid 2006 The Argyle diamond mine is economically feasible because its large reserves and high-grade ore offset a low average diamond value. The estimated value of Argyle diamond production is only US$7 per carat ($35/g); this compares to values of $70 per carat ($350/g) for diamonds produced at the Diavik mine and US$170 per carat ($850/g)