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
Williamson diamond mine Tanzania. Since February 2009 the mine is mostly owned by Petra Diamonds, with 75% ownership, the government of Tanzania owning the remaining 25%. The Williamson diamond mine is a large open pit mine currently about 90 meters (300 ft) deep. Diamond mining operations at the Williamson diamond mine are composed of four distinct activities: mining of the pit, re-treatment of tailings to recover missed diamonds, and gravel mining both on the property and adjacent to the property where gravel has been alluvially deposited. The open pit mining and tailings re-treatment are the largest of the four operations. The mine employs