Diamond Market, Week 35, 2026

The most striking read from week 35 is what didn't leave the market. Off-market listings collapsed 85.84% week on week, from 647,880 to just 91,769, while new listings also pulled back sharply, down 39.59% to 1,227,617. The net effect: active inventory climbed to a record across the last seven weeks at 33.37 million stones, worth roughly $113.3 billion. The market isn't moving faster; it's simply accumulating. Retailers pulled back hard on restocking but held onto what they had.

Against that backdrop, lab-grown median prices put in a move worth paying attention to. The median lab-grown stone listed this week came in at $879.66, up 21.87% from last week's $721.79. Price per carat lifted even more sharply, from $346.76 to $449.52, a 29.63% jump. Natural stones also firmed, with the median up 5.56% to $1,014.04 and per-carat pricing at $1,958.64. Both segments moving up in the same week, against a backdrop of falling overall median prices, tells you the mix is shifting rather than prices repricing across the board. The overall median sits at $1,061, the lowest in seven weeks, because smaller and cheaper stones are claiming a larger share of what's actually trading.

The shape movers this week were pronounced. Pear added 33% in median price (from $690 to $918.50), marquise gained nearly 26% (from $760.05 to $955.69), and oval lifted about 20% to $1,095. Heart shapes moved the other way, shedding 12% to $925.03, and asscher gave back 8.4% to $1,773, though asscher still commands the highest median price of any shape in the new listings data. Round continues to dominate by volume, taking 41.19% of all new listings at 505,517 stones, with a median of $736.74. That's a wide gap from oval and cushion, which both sit above $1,095.

Lab-grown's share of active inventory held near 63.76%, essentially flat against the prior week and the broader seven-week window. The structural shift toward lab-grown has plateaued here for now; we haven't seen meaningful movement in share terms since the high of 64.88% in week 31. Cross-retailer overlap ticked up slightly to 50.28%, and the median spread across retailers held at 81.80%. That spread figure has drifted up through the window, from 75.9% in week 30, meaning the same stone listed across multiple retailers is showing wider price gaps than earlier in the year. Worth keeping in mind if you're shopping across the retailers I follow.

The week's largest listings are worth a mention, if only because the pricing contrast is so visible. Two 51.51ct lab-grown heart stones appeared in the market, IGI-certified G/VS1, listed at $98,210 and $186,775 respectively. That's $1,907 and $3,626 per carat for stones of that size, a fraction of what equivalent naturals would command. The most expensive new listing was a 20.06ct lab-grown pear, F/VS1, at $3,836,520. Lab-grown at that scale is genuinely niche territory.

Going into week 36, the supply picture is the thing to watch. Two consecutive weeks of well below average new listings and a collapse in off-market activity suggest retailers are pausing rather than repositioning. If fresh supply stays light and prices keep firm in lab-grown, the current accumulation could support a median price recovery. But the seven-week downtrend in median price, now at its floor for this window, hasn't reversed yet.

Diamond Market Charts, Week 35, 2026 (24 to 31 August 2026)

The five charts below summarise what the diamond market did during 24 to 31 August 2026. Each is a static image you can save or share. Together they cover where prices sit today, how inventory is moving, the lab-grown versus natural mix, where retailers raised or cut prices, and how much the same stone can vary across competing sellers.

Lucy Market Index

Ten numbers I record every snapshot.

Versus Week 34, 2026

Biggest shape movers

Recent trends

How metrics are tracking across the recent window of snapshots.

How the Lucy Market Index has moved

By origin

Top shapes by new listings

Notable stones

Each stone links to its full Carat Hunter listing.