Global mining giant Rio Tinto is marking the last day of production at its Diavik diamond mine in the Northwest Territories.
The closure has been long planned as the mine approached the end of its productive life.
Diavik, 220 kilometres south of the Arctic Circle, produced more than 150 million carats of rough diamonds over its 23 years of operation.
Though diamond production has wound down, closure activities are set to continue until 2029.
Two other diamond mines are operating in the territory: the Gahcho Kué mine owned by De Beers and Mountain Province Diamonds Inc. and the Ekati mine owned by Australia-based Burgundy Diamond Mines Ltd.
The growing popularity of lab-grown diamonds has cut into the profitability of those operations, and the Northwest Territories government has been working to diversify its economy into new sectors, like critical minerals.
This report by The Canadian Press was first published March 26, 2026.
