Diamond Market, October 2026

October's spreads blew out. For stones listed at more than one retailer, the median gap between the cheapest and dearest listing hit 133%, up from 112% in September. From April through August it sat in a tight band of 82 to 90%. That's the widest I've recorded in seven months, and I'd call it genuinely significant: for the typical stone you can find in more than one place, the highest asking price is now more than double the lowest. One example from this month's list: a 70.83ct lab-grown emerald, I VS2, showing at both $85,579 and $99,271. And by the standards of the median, that gap is mild.

Supply explains a lot of it. Active inventory reached 49.7 million stones, up 9.3% on September and nearly 85% above April's 26.9 million. Listed value climbed to a record $156.5 billion. But cross-retailer overlap fell to 41.1%, the lowest in the window and well down from 50.5% in April. More stock is sitting with a single seller, which makes price comparison harder and gives retailers more room to price on their own terms. The flow matters too. Across the retailers I follow, 2.45 million new stones arrived against 2.19 million that sold, so stock is still building faster than it's clearing.

Headline prices firmed a little. The median stone sits at $1,082, up 2.8%, and the median price per carat recovered 4.6% to $849 after September's slide to $811. Don't read that as a turn, though. Per carat pricing is still about 15% below April's $1,000, and the median active stone grew to a record 1.33ct, so part of this lift is bigger stones rather than dearer ones. Solid, not more.

Lab-grown share eased to 62.4%, its lowest point in seven months and a slow drift down from 64.4% in June. Lab-grown still did most of the listing, with 1.56 million new stones against 1.35 million sold; natural added 899,000 and cleared 844,000, a tighter balance. The price gap between the two is as stark as ever: $344 per carat for lab-grown, $1,733 for natural, roughly five times the cost. Oddly, the priciest stone I saw all month was lab-grown, an 18.09ct F VVS2 emerald asking $3.85 million, ahead of a 23.41ct D flawless natural oval at $3.46 million. That lab-grown price looks ambitious to me (very ambitious).

Shapes split sharply. Marquise jumped 12.8% to a $1,028 median and radiant added 3.8% to $1,176. On the other side, princess fell 10.1% to $850 and asscher dropped 9.6% to $1,102. Trillion lost 10.5%, though on a sample too thin to lean on. Rounds remain the backbone at 41% of new listings, and a handful of names did a fair share of the work, with the five busiest accounting for 31.5% of new stock.

Going into November, my question is whether that spread holds as holiday demand arrives or whether competition pulls it back toward the old 80s range. If overlap keeps falling, it probably won't. For buyers the practical read is simple: shopping around has rarely paid better than it does right now, and princess and asscher cuts look like the best value on the board this month.

Diamond Market Charts, October 2026 (October 2026)

The five charts below summarise what the diamond market did during October 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 September 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.