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
Williamson diamond mine Williamson diamond mine The Williamson Diamond Mine (also known as the Mwadui mine) is a diamond mine northeast of Shinyanga in Tanzania; it became well known as the first significant diamond mine outside of South Africa. The mine was established in 1940 by Dr. John Williamson, a Canadian geologist, and has been continuous operation since then, making it one of the oldest continuously operating diamond mines in the world. Over its lifetime it has produced over 19 million carats (3,800 kg) of diamonds. The Williamson mine, once owned by its namesake Dr. Williamson and later nationalized by the government of