Ekati Diamond Mine and Stewart Blusson who had been prospecting in the region for almost ten years, having found kimberlite indicator minerals as early as 1985. The Point Lake kimberlite was determined to be uneconomic, but its discovery precipitated one of largest staking rushes in mining history, covering most of the area between Yellowknife and the Arctic coast. There are 156 known kimberlite pipes within the Ekati block of claims, including the Point Lake pipe. Ekati officially began operations on October 14, 1998, and was operated by BHP Billiton Canada Inc., a part of the BHP Billiton Group, the world's largest diversified resources
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)