CaratNinety-six percent down — and firming: the strange bottom of the lab-grown market
Q2 wholesale lists show one-carat lab-grown rounds rising for the first time in years while two-carat-plus goods fall twenty percent. Rough is up 25–30. This is what a floor looks like.
Since July 2018, wholesale lab-grown diamond prices have fallen ninety-six percent — one of the fastest commodity collapses in the history of luxury goods. Which is what makes the second-quarter 2026 price lists genuinely strange reading: the average is still down thirteen percent year on year, but one-carat rounds — the engagement-ring workhorse — are up one percent. In this market, a plus sign is an event.
The curve now bends by size. Stones of 1.50 to 1.99 carats are down eleven percent year on year; two carats and above are down twenty, the steepest declines in the categories that once carried the fattest wholesale margins. The goods that made growers rich are the goods still in free fall; the commodity sizes have found buyers at the bottom.
Upstream, the producers have stopped waiting. Rough lab-grown prices have been pushed up twenty-five to thirty percent in recent months — opportunistic moves by growers reading the same firming signals. Downstream, specialty retailers moved twenty-four percent more lab-grown units in the second quarter while total consumer spending on the category stayed flat, locked in the same narrow range it has held for eighteen months. More stones, same dollars: the category is still deflating at retail even as its wholesale floor sets.
Regulators are redrawing the labels while the prices settle. From September 1, Russia will require lab-grown jewelry tags to read 'synthetic' — banning the word 'diamond,' grading nomenclature, and descriptors like 'natural' or 'eco-friendly,' with weights stated in grams only. However the WTO politics of it play out, it is the hardest legal line yet drawn between the two products, and other producer nations are watching.
The desk's view: an eighteen-month flat line in consumer spending against double-digit unit growth means the category's identity has resolved — high-volume, low-price, fashion-adjacent. The one-percent uptick in one-carat rounds is not a recovery; it is the market agreeing, finally, on what a lab-grown diamond is worth. For retailers, the play remains margin discipline and honest positioning, not price speculation.