Rio Tinto Diamond Unit Remains in Red

Rio Tinto’s diamond business incurred a loss in 2025 amid the global market slowdown and as the company’s remaining mine neared its end of life.

Revenue rose 19% to $332 million for the 12 months, it said Thursday. Despite the improvement in revenue, the miner reported an underlying EBITDA loss of $79 million. EBITDA stands for earnings before interest, taxes, depreciation and amortization. However, that figure marks a gentler decline than the $115 million loss it posted in 2024.

Production from the Diavik mine in Canada, its only remaining diamond resource, grew 61% to 4.4 million carats. This reflected the company’s move to mining ore from the new underground portion of its A21 deposit, which produced more diamonds. Rio Tinto began to ramp up output from that area in the last quarter of 2024.

The new A21 underground section is due to be depleted at the end of the first quarter of 2026, at which point the mine will have reached its end of life. Rio Tinto expects to spend approximately $1 billion this year on closure activities associated with Diavik, its Argyle diamond mine in Australia, which ceased production in 2020, as well as a few other projects unrelated to diamonds.

Image: An aeriel view of the Diavik mine. (Rio Tinto)