Anglo American PLC said it may write down the value of De Beers for the third time in two years, the latest sign of sustained weakness in the global diamond market as the storied mining house struggles to find a buyer for the business.

The London-based miner said it is conducting an impairment review of De Beers that could result in a reduction when Anglo reports full-year results Feb. 20. The potential write down would follow a $2.88 billion impairment in 2024 that reduced De Beers’ carrying value to $4.1 billion, itself coming on the heels of a $1.56 billion write down at the end of 2023.

The successive impairments underscore the diamond industry’s protracted downturn, driven by tepid consumer demand in key markets and growing competition from laboratory-grown stones. Anglo’s difficulties in offloading De Beers—it confirmed Thursday a “structured sale process is currently underway”—reflect buyers’ wariness of the sector’s prospects.

Anglo also slashed De Beers’ 2026 production targets; projecting output of 21 million to 26 million carats compared with a prior forecast of 26 million to 29 million carats. The company said it was aligning production “with prevailing demand,” a euphemism for curtailing supply in hopes of supporting prices.

The diamond miner’s pricing metrics paint a stark picture. De Beers’ rough-price index fell 12% in 2025 on a like-for-like basis. When accounting for stock rebalancing—high-volume transactions at lower margins—the index plummeted 25%. Those discounting efforts dragged the average price down 7% to $142 per carat for the year.

Despite the pricing pressure, consolidated rough-diamond sales rose 9% to $2.98 billion for 2025, while volume surged 23% to 23.9 million carats. The figures suggest De Beers moved more stones at significantly lower prices, a strategy that failed to salvage profitability. Anglo projected negative earnings before interest, taxes, depreciation and amortization for De Beers in 2025.

Full-year production declined 12% to 21.7 million carats, with Anglo citing planned maintenance and cost-cutting measures. Fourth-quarter output fell 35% year-over-year to 3.8 million carats.

Anglo has been working to exit De Beers since fending off a takeover attempt by BHP Group last year. The company is pursuing a broader restructuring that includes spinning off or selling multiple assets. De Beers, once the crown jewel of Anglo’s portfolio, has become a liability amid a structural shift in consumer preferences and oversupply concerns.

The diamond market has been pressured by weak demand in China, rising popularity of lab-grown alternatives, and younger consumers’ shifting spending priorities. Industry executives have warned the downturn could persist as the sector adjusts to new market realities.

Anglo American shares have underperformed the broader mining sector over the past year as investors weigh the company’s transformation plans against commodity headwinds and execution risks.