De Beers sale 2026: the rough price base resets

Two things happened to the supply side of the natural market this month. De Beers reported its average rough price index at 65, down 20% year on year, and Bloomberg reported that a jewellery retailer and a luxury group are in talks to buy into the consortium bidding for the company. The first sets the floor under every polished grid. The second decides who is allowed to move that floor.

What the rough price index says going into Q4

De Beers publishes an average rough price index rebased to December 2006 = 100. For the third quarter of 2026 it read 65 — down 20% year on year and 6% from the second quarter. Across the nine months to September 30 the index fell 18%.

Volume went the other way. Third-quarter total sales volume rose 71% to 9.8 million carats and consolidated volume rose 91% to 8.7 million carats, while consolidated revenue rose only 4% to $731 million. The number that reconciles those is the average selling price: $84 per carat, down 45% year on year. Over nine months, total sales volume reached 24.6 million carats, up 37%, of which consolidated volume was 21.2 million carats. Those sold at an average $97 per carat, down 37%, for consolidated revenue of $2.04 billion, down 15%.

That pattern follows a decision rather than a drift. At the July sight — the first under a sightholder contract running to the end of 2028 — De Beers cut rough prices to bring them into line with the market. Volume responded within a quarter. Price did not.

Production moved on its own track. Third-quarter output fell 11% to 6.8 million carats, with Botswana down 20%. On October 16 De Beers took full ownership of Gahcho Kué by acquiring Mountain Province Diamonds' 49% stake, then raised 2026 production guidance to 25–28 million carats from 21–26 million and cut unit-cost guidance to about $70 per carat from about $80. Venetia, meanwhile, mined its final carats before a two-year pause announced in July.

Who ends up owning the supply side

Anglo American holds 85% of De Beers. Botswana holds the other 15% and hosts more than 70% of De Beers' production, which is why its government carries a right of first refusal over any sale.

On July 17, 2026 Botswana's Minister for State President, Moeti Mohwasa, told lawmakers that Anglo had run a competitive process with three shortlisted bidders and had identified the Global Diamond Consortium — led by Gareth Penny, De Beers chief executive from 2006 to 2010 and now chair of Ninety One — as preferred bidder. Anglo has not confirmed the choice, saying only that it is progressing the process. One of the other shortlisted groups is led by Diacore executive chair Nir Livnat. On July 30 Anglo chief executive Duncan Wanblad described the process as being in its last and most difficult stage, said the company was not exclusive with any consortium, confirmed a private sale rather than a listing, and set the goal of concluding during the second half of 2026. Statutory approvals, he added, would take roughly a year after a deal is signed.

Two October reports changed the likely shape of the buyer. Bloomberg reported on October 15 that Signet Jewelers and Richemont are in talks to take minority stakes in the Penny consortium, and that Botswana is nearing agreement to raise its holding to about 25%.

Read as a cap table rather than a headline, that is a producer moving from a diversified mining group to a mix of producer governments and downstream buyers. A retailer or a luxury house on the register has a different interest in the rough price index than a miner does: a miner wants the index high, a buyer of polished wants its input cheap and its category credible. Which of those interests dominates is the open question a desk cannot answer in advance, and it will not be settled on the day of signature — approvals run about a year beyond it. Anglo's own willingness to accept a lower number is already on the record, in write-downs of $1.6 billion in 2023, $2.9 billion in 2024 and $2.3 billion in 2025 against an underlying EBITDA loss of $511 million in 2025. Bloomberg put the price for the 85% stake at about $1 billion in July 2026. Anglo paid $5.1 billion for the Oppenheimer family's 40% of De Beers in 2011.

Consolidation of the share register is not the same event as consolidation of supply, and the second one is further along. Rio Tinto announced Diavik's final production on March 26, 2026, after 23 years and more than 150 million carats, with closure work running to 2029; Argyle closed in 2020; Venetia is paused for two years; and Gahcho Kué now runs to 2028 rather than 2030. A buyer inherits pricing power over a shrinking book, and De Beers' own conduct in July — cutting rough prices to meet the market rather than holding them — is what a producer does when it is setting price to clear volume.

How a rough reset reaches a polished quote

It mostly does not, at least not on the timescale a quote lives on. The rough index fell 18% over nine months and polished asking prices did not follow it down. The Rapaport Trade Diamond Index rose through September: 0.30 ct asking prices up 3.2% on the month and 15.1% for the year to date, 0.50 ct up 2.5% and 5.8%, 1.00 ct up 0.3%, 3.00 ct up 1.5%. The Rapaport Price List itself rose on September 11 for round 0.30–0.69 ct stones in D–G and VVS1–SI1. That is a change to the grid itself rather than to a discount off it — how the Rapaport grid is structured covers the difference.

Smalls rose because round production had already been cut, not because rough got dearer. The short-run polished grid is a function of availability, and availability in the categories a desk actually sells has been tightening: limited supply of 1.00–3.00 ct goods in Belgium, Indian manufacturers buying rough conservatively, and factories planning a November Diwali shutdown. The same quarter's weakness sat where lab-grown competes hardest — smaller, lower-quality natural goods, which is the pressure traced in GIA Premium vs IGI 4Cs.

The platform's own ask data shows the same split by weight rather than by headline.

Where the rough reset does reach a quote is through replacement cost on the next parcel, not through the sheet on the current one. Three adjustments follow from that:

• Separate the base from the discount. The Rapaport grid moved up while rough fell; a back quoted off memory rather than off the current sheet now carries two stale assumptions instead of one. Discount to Rap covers the arithmetic, and Rapaport price list alternatives covers the four references desks quote against instead.
• Price the band, not the market. Divergence by weight is wider than the market-level move, which is the mechanism described in Market Cycles and Signals and sized in how weight thresholds step the price curve.
• Watch availability, not ownership. Rapaport's October 8 market comment records availability limited for 1.00–3.00 ct goods, 2.00 ct especially, with fewer suppliers around. That is readable this week; the cap table is not readable for another year.

Common questions about the De Beers sale and rough prices

Who is buying De Beers, and when will the sale close?

No buyer is confirmed as of October 25, 2026. Botswana's government said on July 17, 2026 that Anglo American had identified the Global Diamond Consortium — led by former De Beers chief executive Gareth Penny — as preferred bidder from three shortlisted groups, and Bloomberg has reported a price of about $1 billion for Anglo's 85% stake. Anglo has not confirmed the choice, and chief executive Duncan Wanblad said on July 30, 2026 that the company is not exclusive with any consortium, that the aim was to conclude during the second half of 2026 as a private sale rather than a listing, and that statutory approvals would take about a year after signing. Bloomberg reported on October 15, 2026 that Signet Jewelers and Richemont are in talks to take minority stakes in the consortium.

What is the De Beers rough price index at now?

The average rough price index stood at 65 in the third quarter of 2026, against a December 2006 base of 100. That is 20% below the third quarter of 2025 and 6% below the second quarter of 2026. For the nine months to September 30, 2026 the index was down 18%, and the consolidated average selling price was $97 per carat, down 37%, across 21.2 million carats of consolidated sales volume.

Does a lower rough price mean polished prices fall?

Not on the same timescale, and not in 2026. The rough index fell 18% over the nine months to September while Rapaport Trade Diamond Index asking prices rose — 0.30 ct up 15.1% year to date and 0.50 ct up 5.8%. De Beers cut rough prices at the July 2026 sight and third-quarter sales volume rose 71% year on year, but goods bought at that sight are sorted, cut and polished before they reach an offer, so the cost change lands on the next parcel rather than the current sheet. The current sheet is set by availability in each weight and grade band.

How does consolidation affect diamond pricing power?

Less than the change of owner suggests. De Beers cut rough prices at the July 2026 sight and third-quarter volume rose 71% year on year while the price index fell 20% — a producer exercising pricing power does not need to do that. The sale moves Anglo American's 85% stake to a mix of producer governments and downstream buyers, with Botswana's 15% holding reportedly rising to about 25% and statutory approvals running roughly a year past signature. In the meantime the variable that moves a quote is availability per weight and grade band, not the share register.

What does De Beers taking full ownership of Gahcho Kué change?

De Beers bought out Mountain Province Diamonds' 49% stake on October 16, 2026, moving from 51% to full ownership, and raised 2026 production guidance to 25–28 million carats from 21–26 million while cutting unit-cost guidance to about $70 per carat from about $80. The Tuzo Phase 3 expansion has been paused since February 9, 2026, and De Beers' 2025 annual report states that without it the mine is anticipated to operate only until 2028, rather than to 2030 as the expansion would have allowed.

Price the base you can measure, not the owner you cannot

The ownership question will take another year of approvals to answer, and nothing about it is quotable to a buyer tomorrow. The rough index at 65, the $84 per carat realised in the third quarter and the Rapaport sheet's September increase all are. A desk that marks its base to the sheet it can read, tracks listing depth per comparable, and treats the sale as a reason to shorten its repricing interval rather than to guess at a number will be positioned either way the cap table settles. Origin is already a priced variable in its own right, as Diamond tariffs 2026 sets out; ownership is the next one.