Diamond Market, Week 30, 2026

Median price per carat hit $976.15 this week, the highest reading in seven periods, while active inventory fell to its lowest point in the same window at just over 30.3 million stones. That pairing matters. New listings dropped 15.8% to 1.22 million, and off-market activity nearly halved versus the prior week: 83,952 exits against 160,081. The market is quieter, and it's pricing that way.

Natural diamonds did most of the price work. Median natural prices jumped to $1,738 from $1,391 the prior week, a gain of nearly 25%, with per carat pricing rising from $2,300 to $2,650. But natural supply contracted sharply: 413,523 new natural listings versus 541,064 the week before, a 23.6% pullback. Lab-grown stones told a different story at the per carat level. Lab-grown median listing prices rose 19.7% to $1,120, but median per carat pricing fell 21.7% to just $422.73. Rising sticker prices alongside falling per carat value signals mix shift more than real price movement. Larger lab-grown stones are entering inventory, and the per carat rate is compressing as they do.

Asscher is the shape to note this week. Median new listing prices rose 53.8% to $2,322.60, making it the priciest of the standard shapes to enter market this period. Volume was modest at 17,437 new listings, so some of that move is mix, but the direction is clear enough to watch. Trillion saw a similar pattern: up 84.3% in median to $1,401 on just 552 listings, thin enough that a handful of stones can swing it. Round remained dominant at 45% of new listings, with a median entry price of $1,016. Oval slipped 1.3% to $1,237 and marquise edged down 2.1% to $1,244. Not dramatic, but both have been consistently near the top of the new listing mix, and the softness is worth flagging.

Cross-retailer overlap continued its drift, hitting a seven period low at 47.0%, down from 52.5% at the peak in late June. The median spread between retailers tracking the same stone also compressed to 75.9%, another record low for the window. Both trends together suggest the market is differentiating: fewer stones duplicated across retailers, and tighter price convergence where overlap remains. Concentration stayed elevated, with the top five sources accounting for 48% of new listings. A handful of names is still doing most of the work.

The most expensive new arrival was a 50.5ct D VS1 natural pear, GIA certified, listed at $5.3 million. A 1.4ct Fancy Vivid Blue radiant VS2 came in at $2.84 million, a reminder that colour commands premiums that carat weight alone doesn't explain. On the lab-grown side, a 10.05ct E VVS1 round hit $2.57 million and a 21.51ct E VVS2 emerald listed at $2.5 million, both pushing into territory that would have seemed outlandish for synthetics not long ago. Largest in inventory was a 91.42ct lab-grown cushion at $166,312, roughly $1,818 per carat, which underlines how dramatically the economics shift at scale in the lab segment.

Going into week 31, the key question is whether the supply tightening holds. New listings have been falling across seven periods and active inventory is at its lowest in the window. If that trend continues alongside further per carat price gains, buyers in the 1 to 2 carat natural segment may start to feel it. The lab-grown per carat slide is a counterweight, but it's moving in a different direction for a reason worth watching.

Diamond Market Charts, Week 30, 2026 (20 to 27 July 2026)

The five charts below summarise what the diamond market did during 20 to 27 July 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 29, 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.