The diamond market spent the week confirming what the price lists have signaled all year: rough and polished are settling into two distinct tracks, one anchored to scarcity and one anchored to production cost. The clearest data point came from De Beers, whose consolidated realized rough price fell to $155 per carat, down 5 percent from $164 a year earlier. For a trade that has spent three years waiting for a clearing level, that figure is the closest thing to a reference point on offer.

De Beers cuts to clear

De Beers reduced rough prices by 10 to 15 percent on goods above three-quarters of a carat at its most recent sight, and the company's average rough price index has fallen roughly 14 percent as it sold assortments at thinner margins. Sales rose once the cuts took effect, a straightforward demonstration that sightholders will buy at the cleared price and resist anything above it. The miner has confirmed 10 rough sales across the 12-month 2026 schedule and extended its current sightholder agreement through June 30, holding the system steady while it negotiates terms.

De Beers has thinned supply to match demand rather than chase volume. Sales slid from nearly $6.6 billion in 2022 to $3.5 billion last year, and production fell from 35 million to 21.7 million carats over the same period. The structural backdrop has not changed. Weak luxury consumption in China and the continued flood of lab-grown goods into the US market have produced three consecutive years of contracting natural-diamond demand. Anglo American CEO Al Cook told the Reuters NEXT Europe conference in mid-June that the long-running De Beers divestment has reached its most advanced stage in two years, with a sale possible in the coming weeks and Angola's Endiama among the named suitors.

Lab-grown finds its production-cost floor

On the synthetic side, the price slide has largely run its course. A one-carat round lab-grown stone now clears roughly $400 to $725 per carat at wholesale, with retail averages near $759 for rounds and $827 for ovals. That represents a decline of 85 to 88 percent from the 2020 peak near $3,410 per carat, and the rate of decline has flattened as premium certified stones approach the cost of producing them. The steepest cuts are behind the category. The floor is low enough that lab-grown now functions as a fashion-jewelry input rather than a store of value, which is precisely how the mass-market chains have begun to merchandise it.

The bifurcation is now measurable

The gap between the two products is no longer rhetorical. Natural diamonds at identical specifications hold a scarcity premium of five to fifteen times over lab-grown equivalents. A one-carat D/VVS2 natural stone budgets at $5,000 and up, while a comparable lab-grown sits in the mid-hundreds. GIA-graded goods continue to command a premium over IGI-certified stones at matching specs, which keeps certification a live variable in any wholesale negotiation, especially as lab-grown reports proliferate and buyers scrutinize the grading lab as closely as the four Cs. For retailers, the practical effect is two separate merchandising strategies under one roof: natural for the bridal and investment conversation, lab-grown for volume and price-point fashion pieces.

The corporate response to that split is covered in our industry report on Pandora's diamond and metal strategy, and the broader weekly picture sits in our trade week wrap.

Where the data points next

The question for the second half is whether $155-per-carat rough marks a clearing level or a way station. De Beers has shown it will trade margin for volume, and sales rose when it did. But with lab-grown anchored near its production floor and natural demand still contracting in its two largest markets, the realized rough price has further to prove before anyone in the trade calls it a bottom. The next sight figure, and whatever buyer finally closes on De Beers, will decide which it is. For independent jewelers, the immediate takeaway is simpler: the price gap between a $5,000 natural one-carat and a $700 lab-grown equivalent is now wide enough that the two products no longer compete for the same customer. The job at the counter is to stop treating them as substitutes and start selling them as separate categories with separate margins.