Diamond News 2025-2026: What Actually Changed

Date: announced 2 June 2025; effective 1 October 2025.
What changed: GIA stopped reporting lab-grown diamonds on the D-Z colour and FL-I3 clarity scales used for natural diamonds. The new system gives every lab-grown submission one of three outcomes: Premium (D colour, VVS clarity or higher, Excellent polish and symmetry), Standard (E-J colour, VS clarity, Very Good polish and symmetry), or no grade at all².

Why it matters: the 4Cs scale was developed for natural diamonds where colour and clarity vary widely. More than 95% of lab-grown diamonds cluster within a narrow quality band, so the granular scale produced spurious precision. The new tier system reflects what is actually different about lab-grown stones at the population level.

What buyers should do: pre-October-2025 GIA lab-grown reports remain valid with their original 4Cs grades. New stones graded under the new system carry Premium or Standard. IGI, the other major lab-grown grading lab, continues to use the traditional D-Z and FL-I3 scales. Full detail is in Chapter 5.

Date: closure announced 9 May 2025; end of jewellery production announced June 2024.
What happened: De Beers, the world's largest natural-diamond producer, announced the closure of Lightbox Jewelry, its lab-grown consumer brand launched in 2018¹. Lightbox had been a deliberate price-floor experiment, set initially at $800 per carat regardless of quality. As third-party lab-grown wholesale prices fell roughly 90% over six years, the price floor became indefensible. Lightbox lost $101.3 million in 2023 and $22.3 million in 2022.

Why it matters: the closure was widely read as a marker that the price-floor strategy had failed and that lab-grown was on a cost-plus pricing trajectory. Element Six, De Beers' synthetic-diamond arm that produced for Lightbox, now focuses exclusively on industrial applications. Independent lab-grown producers continue to sell to retail in volume.

What buyers should do: the closure does not directly affect the broader lab-grown retail market, which has many independent suppliers. Existing Lightbox warranties and customer support remain in place during the wind-down. The strategic lesson - that lab-grown pricing is on a cost-plus path rather than a brand-premium path - reinforces the resale-value picture.

Date: announced in Anglo American's 2024 strategic update.
What happened: Anglo American set out a plan to separate or divest De Beers, treating the diamond business as non-core to its mining portfolio³. The separation mechanism and timeline are still evolving and have been the subject of continuing trade-press coverage.

Why it matters: De Beers had been part of Anglo American since 2012 and accounts for the majority of global natural-diamond rough by value. The separation signal told the market that Anglo American's assessment of medium-term natural-diamond demand had weakened materially. The signal compounds the Lightbox closure narrative: the incumbent natural-diamond producer is repositioning around its core, not investing in new categories.

Date: Antwerp Q1 2026 trade figures (Jan-Mar 2026 data, published April 2026).
What happened: Antwerp rough-diamond prices fell roughly 27% year-on-year, from $99 to $72 per carat, while rough import volumes rose 35.7%⁴. Across the whole Antwerp trade, volumes were up almost 20% but value only 3.7%: many more carats moving, at much lower per-carat rough prices. The Antwerp figures follow a full-year 2025 in which total trade value fell 22.4% to $19.1 billion.

Why it matters: Antwerp handles approximately 86% of the world's rough diamonds by value, so AWDC figures are a reasonable proxy for global natural-rough activity. A 27% year-on-year fall in rough prices is large by the standards of the rough-diamond market. Polished moved the other way in the same quarter: international polished prices rose 11.6% year-on-year per IDEX reporting, suggesting the adjustment is concentrated in rough while the polished market firms.

What buyers should do: rough-price weakness eventually shows up at retail, though with substantial lag and not in full. The flow-through from rough to retail takes 6 to 18 months, and the early-2026 polished-price recovery means natural retail prices are unlikely to fall as far as the rough headline suggests.

Date: Q1 2026.
What happened: Edahn Golan reports indicate global wholesale prices for lab-grown diamonds fell 14% year-on-year in Q1 2026, with mid-stream prices for loose stones declining another 14%, and 3-carat round diamonds down 28% YoY as the weakest category⁵. The pace of decline appears to be easing compared to 2022-2024 but has not yet stabilised.

Why it matters: lab-grown wholesale has been falling continuously since 2018 (see Chapter 8). Q1 2026 figures suggest the market is approaching a cost-plus floor rather than a free-fall, but the floor has not yet been clearly established. Continuing pressure comes from low-cost Chinese production capacity, US supermarket-driven retail pricing, and the structural lack of supply constraint for synthetic stones.

The five events together tell one consistent story: the diamond market is undergoing a multi-year correction with both cyclical (post-pandemic inventory overhang) and structural (rising lab-grown share, falling lab-grown wholesale, brand-incumbent retreat from synthetic premium positioning) components. For buyers, the immediate practical implication is that 2026 is a buyer's market for both lab-grown and natural at the wholesale level, with retail prices following more slowly. For sellers and the secondary market, the resale gap that has always existed for diamond purchases has widened, particularly for lab-grown stones.

For the full chapter-by-chapter context, see the homepage table of contents, the market-data chapter, and the natural-diamond losing-value appendix.