On Tuesday 2 September 2026, Rapaport quietly announced something the wider media has barely noticed: for the first time in fifteen months, the RAPI 1-carat diamond price index posted a positive month. It rose 0.5% in August, following flat or negative figures going all the way back to May 2025.
On its own, half a percent doesn't sound like news. In the context of two and a half years of falling headlines, it is one of the clearest signals yet that the natural diamond market has found its floor and started climbing back. From Antwerp, we've been reading the same signal in the trade for several weeks. This is what the data actually says — and what it means if you're thinking about buying.
What Rapaport announced
The Rapaport Trade Diamond Index (RAPI™) tracks asking prices for round D-H, IF-VS2 diamonds — the benchmark quality most commonly traded in Antwerp and worldwide. The August 2026 numbers, published on 2 September:
- 1-carat RAPI: +0.5% — first positive month since May 2025
- 0.30-carat RAPI: +2% — continuing its recent rebound
- 0.50-carat RAPI: +2.5% — the strongest monthly gain
- 3-carat RAPI: −0.4% — a minor correction after 18 months of stability
The pattern is important. Small stones are leading the recovery, not the top end. That's because miners and manufacturers have finally cut production hard enough to rebalance the supply of exactly those categories that suffered most in 2025. The 1-carat segment — long the swing category in engagement rings — has stabilised as inventory declines and, in Rapaport's own words, consumers are cooling on lab-grown diamonds.
That is a significant sentence to see coming from Rapaport itself.
Why this signal matters
For most of 2024 and 2025, the diamond news cycle was dominated by one story: prices are falling. Both mainstream Dutch and Belgian coverage (NOS, VRT NWS) framed the sector as being in structural crisis, with lab-grown alternatives and shifting generational preferences cited as the drivers. Half of that story was true. Half was wrong.
The half that was true: natural wholesale prices dropped 25–30% from their 2021 peak, and commercial-grade stones under 2 carats — the ones most directly comparable to mass-produced lab-grown — have been hit hardest. Lab-grown wholesale prices themselves have fallen 96% since 2018, according to analyst Edahn Golan's Q2 2026 tracking.
The half that was wrong: the industry is not collapsing. It is bifurcating. Investment-grade naturals (D–F colour, VS clarity or better, 2 carats and up) have held or grown value throughout the decline, and the commercial-grade segment is now recovering. That is precisely what the September Rapaport data confirms
The context behind the numbers
1. De Beers halted its Venetia mine (13 July 2026). The 4,400-employee mine in South Africa, producing predominantly smaller, lower-value stones, was paused for two years. Rapaport's coverage made clear this was a strategic supply cut, not an operational failure — Venetia's average realised prices had fallen to just $66 per carat versus $353 in Namibia.
2. Antwerp posted its first meaningful growth since 2022. The AWDC's first-half 2026 figures, released 13 July, showed total trade up 9% year-on-year to $10.6 billion, with the number of diamonds traded up 14%.
3. Miner losses translated into supply discipline. Alrosa's H1 2026 revenue fell 36% and De Beers' fell 19% to $1.58 billion — but De Beers trimmed its losses through cost cuts and more stable prices.
What this means for buyers in September 2026
If you're considering a natural diamond purchase, three practical implications:
Waiting for prices to fall further is now a losing strategy for premium stones. The floor is in for investment-grade naturals. Commercial grades may still soften slightly, but even there the September Rapaport data suggests the worst is behind.
The market rewards grade over size. A D/VVS 2-carat has held value materially better over the last 18 months than an H/SI 1-carat — and that pattern accelerates as high-end demand hardens.
Certification matters more than ever. With GIA restructuring its lab-grown reports and HRD partially withdrawing from that segment, the certificate itself is becoming a clearer market signal. See our diamond certification guide for what to look for.
The Antwerp read
From the diamond district, the September Rapaport announcement doesn't feel like the beginning of anything — it feels like the outside world finally catching up to what the trade has been seeing since Q2. The number of diamonds physically moving through Antwerp has been up 14% since January. The order books at cutting houses in the region have been rebuilding. Larger stones have been quietly stable while the mainstream press wrote obituaries.
None of this makes the diamond sector immune to further shocks. But it does mean the "diamond market is collapsing" story that dominated 2024–2025 is no longer accurate as of September 2026.
For the full 2026 context on pricing across grades and sizes, our Natural Diamond Prices in 2026 guide walks through the current bands. For the broader science and history of why these stones hold value, see our Famous Diamonds encyclopedia.
Questions about a specific stone or the current market moment? We're always available to talk — reach us at questions@diamantwerp.be or via WhatsApp on +32 471 01 79 97.
