Lab-Grown Diamond Price History

The lab-grown price story since 2018 is one of supply scaling outpacing demand growth, with the result that wholesale prices have compressed steadily. The compression has been most visible in three places: in the Bain wholesale ratio, in the De Beers Lightbox public pricing decisions, and in trade-press reporting on Indian and Chinese producer margins.

We use these three sources here because they are publicly cited and can be linked. We deliberately do not include retailer-quoted prices because they are promotional and not directly comparable. The picture that emerges is consistent across the three sources, even though each captures a different slice of the market.

Lightbox is the cleanest single price-history anchor in the lab-grown category, because De Beers operated it with a deliberate published linear-pricing model and made each price decision visible¹².

At launch in May 2018, Lightbox sold lab-grown diamonds at eight hundred dollars per carat, regardless of colour or clarity grade. The pricing was branded transparent and was widely covered in trade press as the first time a major natural-diamond producer publicly committed to a fixed lab-grown per-carat price point.

In 2024, De Beers reduced the Lightbox per-carat price from eight hundred to five hundred dollars. The cut was a thirty-seven and a half per cent reduction, applied uniformly. Trade press read the cut as evidence that even a major-brand operation could not hold a high lab-grown per-carat price point against ongoing wholesale compression⁵.

In 2025, De Beers announced the closure of Lightbox⁶⁷. The brand was wound down. The closure was reported widely in mainstream media as a notable signal that lab-grown diamonds, at the major-brand retail level, could not sustain the original 2018 economics.

Bain & Company's Global Diamond Industry Report tracks polished lab-grown retail and wholesale ratios versus natural across multiple reporting windows³. The 2023 to 2024 window placed polished lab-grown retail at roughly thirty per cent of natural retail and wholesale at roughly fourteen per cent of natural wholesale, as discussed in detail in Chapter 7.

The trend over the years before 2023 was a steady decline. In 2018, around the Lightbox launch, the lab-grown polished retail ratio was closer to fifty per cent of natural; by 2024 it had fallen to roughly thirty per cent, with wholesale falling further. The headline figure that the trade and consumer press often cite, that lab-grown wholesale has fallen by roughly ninety per cent since the early lab-grown period, is consistent with this trajectory and is broadly supported by Rapaport reporting⁵.

Natural-diamond pricing has its own trajectory over the same period. AWDC's Q1 2026 press briefing reported a roughly twenty-seven per cent year-over-year decline in Antwerp rough-diamond trade values, on three point seven per cent volume growth⁴. The natural-rough decline is attributed to weak polished demand carrying over from 2024, inventory overhang, and synthetic-substitution effects.

The natural and lab-grown weaknesses are happening in the same time window but reflect different mechanisms. Natural rough is responding to demand softness and inventory cycles against an inelastic supply, with prices set by De Beers Sights, ALROSA tenders, and other producer-buyer relationships. Lab-grown wholesale is responding to continued production capacity additions against a backdrop of demand growth that has not kept pace.

Where this fits in the reference

The next chapter, Market Data, sets out the broader AWDC and Bain figures for 2025 to 2026 in more detail. Chapter 14 discusses what the cost-plus pricing trajectory means for resale values.