1991 Discovery of Diamonds in the NWT
The 1991 announcement by Charles Fipke and Stewart Blusson, and their partner BHP Minerals, that diamonds had been discovered in a sample of rock taken from Lac de Gras started the greatest mineral staking rush in Canadian history.
Fipke and Blusson had been on the hunt for Arctic diamonds for more than a decade prior to this discovery. They were convinced that the geologic conditions northeast of Yellowknife (map) were, contrary to a commonly held belief, perfect for the presence of kimberlite.
Kimberlite, the stone in which diamonds are found, is extremely rare. Billions of years ago high temperature and pressure deep within the earth transformed simple carbon into diamonds. Millions of years ago, when the earth’s core was hotter than it is today, explosive but short-lived eruptions of gaseous kimberlite brought these diamonds to the surface creating a narrow pipe.
There are fewer than ten thousand occurrences of kimberlite in the world and very, very few of these contain diamonds. Kimberlite is a very soft rock and eight to ten thousand years ago continental glaciers scoured out the tops of these pipes and when the ice melted these pipe tops became lakes.
Finding these kimberlite pipes can be difficult but fortunately kimberlite also contains what are called ‘indicator minerals’ – chrome diopside, pyrope, garnet, ilmenite and olivine – and finding these indicator minerals in alluvial deposits can lead the way back to the kimberlite pipe, which is the process used by Fipke and Blusson to find the Northwest Territories’ first diamondiferous kimberlite pipe.
This discovery of diamonds in the Lac de Gras area marked the beginning of unprecedented economic growth in the Northwest Territories. Canada’s first diamond mine, Ekati Mine, was built at the site of Fipke and Blusson’s discovery. A second diamond mine was built by Diavik Diamond Mines at Lac de Gras and by 2005 a third mine, the De Beers’ Snap Lake project, is expected to begin production. Canada is now the world’s third largest diamond producing nation, by value, behind Russia and Botswana.