Dominion Diamond Corporation formerly known as Harry Winston Diamond Corporation and before that Aber is a Toronto, Ontario, Canada, specialist diamond mining and retail company. The company holds a 40% stake in the Diavik Diamond Mine Project. Production at the Diavik Diamond Mine, Canadas second diamond mine, is operated by Dominion Diamond Corporations 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 Billitons diamond assets; the primary asset is the Ekati Diamond Mine, which is adjacent to the Diavik Mine.