The Diavik mine, which is closing after more than two decades in operation, was discovered in 1991 beneath a frozen lake in the sub-arctic tundra of the Northwest Territories of Canada.
Yellowknife, Canada-Rio Tinto delivered its final production of ore from the Diavik diamond mine in the Northwest Territories (NWT) of Canada on March 24, marking the beginning of the end for the 23-year-old mine.
The mine, located in a remote area less than 150 miles south of the Arctic Circle, produced more than 150 million carats of rough diamonds while in operation and became a major economic pillar of the region.
"This is an historic day for Diavik and the Northwest Territories and a great source of pride for this unique Canadian success story," said Diavik Chief Operating Officer Matthew Breen.
"Diavik has been an inspired collaboration between a modern mining company and Indigenous partners with an enduring legacy of socioeconomic benefits for the North."
Indigenous government organizations, government representatives, and other stakeholders attended a celebration at the mine, formally marking the completion of production.
Closure activities will extend to 2029, followed by a period of post-closure monitoring, said Rio Tinto, the mine's sole owner since 2021.
"We look forward to continuing to respectfully reclaim the land in line with our commitments to, and in partnership with, the Government of the Northwest Territories and Indigenous partners," Breen said.
The final production of rough diamonds will be polished and sold through 2026 and beyond by Rio Tinto's international network of customers and its Select Diamantaires.
Excluding Diavik, there are two active diamond mines in Canada-Ekati (owned by Burgundy Diamond Mines) and Gahcho Kué (owned by De Beers Group).
Diavik, comprising four pipes, was discovered in 1991 beneath Lac de Gras, a lake in the sub-arctic tundra of Canada, about 190 miles northeast of Yellowknife.
Mining began in 2003.
Utilizing both open pit and underground mining methods, Diavik produced predominantly white gem-quality diamonds, a small proportion of yellow diamonds, and a handful of pink stones.
In a remarkably rare instance last summer, it yielded a violet diamond.
Among the most noteworthy discoveries is a 552.74-carat yellow diamond recovered in 2018, which holds the title for the largest diamond ever found in North America.
The Government of Northwest Territories has called Diavik "a pillar of the NWT economy."
In addition to producing more than 150 million carats of rough diamonds, the operation has supported more than 1,100 jobs annually and contributed nearly 10 percent of territorial GDP.
"The mine invested approximately $11.75 billion over its lifespan, including $8 billion in the North, while helping build Indigenous partnerships, local businesses, and a highly skilled northern workforce," it said in a statement.
Though its original life-of-mine was forecast for 2025, the transition of its A21 pipe to underground mining in late 2024 extended Diavik's life into the first quarter of 2026.
Planning for the mine's closure, however, commenced before the mine even began production, Rio Tinto said, with considerations for safety, land use, landforms, water, biodiversity, community capacity, and resource development.
The buildings on site are designed to be demolished and disposed of safely, according to its website, and when mining ends, the embankments will be breached and lake water will flow back into the open mines, to be connected to the lake.
"Forty years ago, there were very few people who believed there were diamonds in Canada – even fewer could have foreseen how the Diavik story would unfold. To arrive at this milestone has required vision, courage, and determination to overcome significant challenges to mine diamonds beneath a frozen lake in one of the world's most remote and pristine ecosystems," said Sophie Bergeron, Rio Tinto's iron, titanium, and diamonds managing director.
"Today, Diavik's influence stretches into many spheres and over many continents, and I am very proud to acknowledge all those people who have contributed to the discovery and development of the mine and the production and marketing of some of the finest diamonds the world has ever seen."
