Lac de Gras Lac de Gras Lac de Gras is a lake approximately north east of Yellowknife, in the Northwest Territories of Canada. Lac de Gras was the centre of the diamond rush of the 1990s. There are two working, and one closed, diamond mines in the area, Diavik Diamond Mine, Ekati Diamond Mine, and the care and maintenance Snap Lake Diamond Mine. It was called Ekati by aboriginal peoples. The lake is ultraoligotrophic but supports a slow-growing but stable population of some eight species of cold-water fishes, including round whitefish, cisco, and lake trout. Lake trout dominate the lake, both numerically and
Williamson diamond mine years of operation, average ore grade was about per hundred tons (60 mg/t); in the first few years of full operation grades were as high as per hundred tons (124 mg/t), or 10 times the ore realized today. Production in the 1950s and 1960s was usually between 500,000 and 750,000 carats (100 and 150 kg) per year; the peak year of production was 1966, when 924,984 carats (185 kg) were produced. Today production levels for all Williamson mine diamond recovery activities is about 300,000 carats (60 kg) per year. Notable stones produced at the Williamson mine include the Williamson pink