Rio Tinto’s Diavik diamond mine in the Northwest Territories is set to close in approximately 18 months after almost a quarter of a century of operations. Over 144 million carats of rough diamonds have been recovered at Diavik through a combination of open-pit and underground mining since it entered commercial production in 2003, and the mine is a major contributor to the economy of the Northwest Territories, accounting for more than 10 per cent of the territory’s gross domestic product.