Diamond Market, Week 36, 2026

2,395,362 new listings entered the market in week 36, almost double the prior week's 1.2 million and a record high across the seven weeks I've tracked. Natural diamonds drove the bulk of the surge: new supply rose 225% from the prior week to 1,224,961 stones, briefly edging past lab-grown additions for the first time in months. That volume hit a market already sitting at peak active inventory, and prices didn't respond upward. They fell.

Cross-retailer overlap dropped to 44.5%, down nearly six points from 50.3% last week and the lowest reading in seven weeks. The median multi-retailer spread compressed alongside it, from 81.8% to 71.9%, also the lowest in the period I track. Together, these numbers describe a structural shift worth watching. Retailers are stocking more differentiated inventory than at any point this year, and where the same stone does appear across multiple platforms, the pricing distance has narrowed sharply. That's not just price pressure; it's the market becoming simultaneously less interchangeable and more competitive at the stone level.

Lab-grown pricing took the sharpest drop of the period. The median lab-grown stone fell from $879.66 to $666.45, a decline of 24% in a single week. Per carat pricing moved from $449.52 to $379.73. Natural held considerably firmer: median natural price slipped just 1.4% to $999.92, with per carat value settling at $1,881.14 from $1,958.64. The natural to lab-grown per carat ratio now sits at roughly five to one. Lab-grown removals from market were actually down slightly this week, so the price compression isn't a clearance story. Supply is moving through at lower prices, and there's no floor visible yet.

Shape pricing had wide swings. Trillion cuts fell 41.6% to a median of $474, though at 1,689 new listings the volume is thin enough that a single batch can skew the number. Asscher is harder to dismiss: down 31.9% to $1,207.44 on 21,953 new stones, that's meaningful volume behind the drop. Marquise slipped 20.7% to $758.06. Emerald cuts were the standout on the other side, up 4.6% to $1,069.43 on 126,038 new listings, and radiant stepped up 2.1% to $1,221. Round continues to anchor supply at 53.7% of all new listings, with a median of $722.55.

Three GIA-certified natural pears above 25 carats were among the most expensive stones on market this week, led by a 25.65ct E VVS2 at $3,129,956. Two D Flawless pears just above 25 carats followed at $2.6 million and $2.59 million. At the other extreme, the largest stones on market were a pair of lab-grown cushions above 55 carats, priced between $139,000 and $174,000. That pricing reflects what lab-grown has become: extraordinary size is now largely accessible, and it's not priced like a rarity.

The question going into week 37 is whether this listing surge holds or was a one week event. If new additions stay anywhere near 2.4 million, pressure on median prices will intensify further. Lab-grown is already repricing faster than most anticipated, and the per carat value erosion shows no sign of slowing. With cross-retailer overlap at its lowest in seven weeks, any reversal back toward uniform inventory across platforms would signal retailers retreating on differentiation, which typically means the price competition sharpens before it eases.

Diamond Market Charts, Week 36, 2026 (31 August to 7 September 2026)

The five charts below summarise what the diamond market did during 31 August to 7 September 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 35, 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.