Rio Tinto is seeing a major boost in diamond production as it shifts operations underground at its flagship Diavik mine. After dealing with temporary closures due to ground instability, the mining giant is now ramping up operations, leading to an 18% year-over-year increase in fourth-quarter output, totaling 775,000 carats.
The transition marks the completion of the first phase of underground mining at the A21 pit, which ceased open-pit production at the end of 2023. As the company fine-tunes processing, commercial production in this area is expected to scale up quickly. In addition, operations at other sections of the deposit have resumed after a brief suspension due to subsidence concerns in July.
Carat recovery surged 43% from the previous quarter, reinforcing the benefits of the underground transition. However, total annual output fell by 17% to 2.8 million carats, with processed ore down 25% to 1.3 million carats.
Diavik remains Rio Tinto’s sole diamond mine following the 2020 closure of Australia’s Argyle mine. The company secured full ownership of Diavik in 2021 after acquiring its joint-venture partner's stake. Meanwhile, Rio Tinto has divested from the Fort à la Corne diamond project in Canada to focus on its core mining operations and exploration efforts, including an active diamond-exploration program in Angola.
Investing $40 million into underground mining at A21, Rio Tinto projects an additional 2 million carats of rough diamond production, extending the mine’s lifespan until early 2026. Despite the surge in production, the company has yet to release its forecast for 2025, leaving the industry eager to see what’s next for the mining powerhouse.