Lac de Gras a wide and long stream called the Narrows. The median flood peak discharge in the Narrows is making it an important corridor for fish movements. 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
Merlin diamond mine mines worldwide, and a mere 5% gem-quality production at Australia's largest diamond mine, Argyle diamond mine. The high ratio of gem-quality diamonds is responsible for a relatively high value of $108 USD per carat (540 $/g). The known ore grade at Merlin is about 0.2 carats (40 mg) per tonne, although exploration continues under the mine's new owner. The largest diamond produced at the Merlin mine measured 104.73 carats (20.946 g), the largest ever found in Australia, and has been valued at over $525,000 USD . The mine and mining rights were sold by Rio Tinto Group, to Striker Resources,