$705 for a one-carat lab-grown, on asking prices spanning 17.6 times
The reference price this paper's tape carries for a one-carat lab-grown diamond is $705 today. The same page shows one-carat rounds offered between $185 and $3,247, and a second source read $550 three weeks ago.
By The Diamonds Desk
What changed
The lab-grown reference on this paper's tape reads $705 a carat this morning, taken from CaratRadar's one-carat round average and confirmed at source, where the page is dated 17 August and states that it refreshes daily.
What it means
- A single average across a seventeen-fold range is not a price, it is a summary statistic wearing a price's clothes, and the trade should stop quoting one. Natural diamonds have Rapaport and RAPI, which this paper has spent a fortnight failing to read behind a paywall but which at least exist.
- Lab-grown has aggregator averages that disagree by 28% and ranges that disagree by 1,700%, and the gap between the cheapest and dearest one-carat is not error, it is cut quality, growth method and brand pretending to be the same product. The useful number for a retailer is not $705.
- It is the range, and the fact that nobody publishing an average is being paid to tell you how wide it is.
Key figures
| one-carat round average, six days | $705 |
|---|---|
| cheapest one-carat offered on the same page | $185 |
| dearest one-carat on the same page | $3,247 |
| the spread, derived here | 17.6× |
Source: Lab-grown, 17 August
Four readings in a fortnight
The series this paper has printed runs $727 earlier in the month, $711 on 11 August, $707 on the 14th and $705 today: down 0.84% in six days and 3.03% from $727.
That is a slow, orderly decline rather than the collapse the category is usually described with, and it is the fourth consecutive reading this paper has published in the same direction.
The number underneath the number is the one worth printing. The same page that averages a one-carat round at $705 shows the offers it is averaging running from $185 to $3,247 for the same nominal weight and shape, a spread of 17.6 times, this desk's division.
At two carats the cushion range runs $345 to $6,984 and at three carats $449 to $12,050.
An average sitting inside a seventeen-fold range is doing an enormous amount of work, and a jeweller quoting $705 to a customer is quoting the midpoint of a market in which the same specification is being offered at a quarter of it and at four and a half times it.
One nominal carat, lab-grown · dollars per carat, asking
Source: Lab-grown, 17 August
The range under the average
A second source disagrees, and this paper carries both. Its own natural and lab-grown price lists, compiled on 25 July from a live retail sample, put the one-carat lab-grown round at $550 a carat against a natural one-carat round at $4,581, a multiple of 8.3.
CaratRadar's $705 is 28.2% above that $550, this desk's arithmetic, on a gap of three weeks and two different samples of the same market.
Neither figure is wrong and the divergence is disclosed rather than resolved: one is a live retail asking average from one aggregator, the other a six-retailer median from another, and there is no clearing exchange behind either to settle the question.
In a market with no scarcity and no benchmark, the price is whatever the sample says.
| Figure | |
|---|---|
| Dearest Offer On The Page | $3,247 |
| The Average Quoted | $705 |
| Carat Capital List, 25 July | $550 |
| Cheapest Offer On The Page | $185 |
Notes on this table
All four describe a one-carat round lab-grown diamond. The top and bottom are the ends of the range the $705 average is drawn from, read 17 August 2026. The $550 is this paper's own price list of 25 July from a six-retailer sample; CaratRadar's average is 28.2% above it, this desk's arithmetic, and the divergence is disclosed rather than resolved. Carat Capital graphics desk.
What the trade body says instead
Against that, the category's own trade body spent last week arguing the problem lies elsewhere.
Marty Hurwitz, executive director of the Grown Diamond Trade Organization, told JCK on 14 August that lab-grown diamonds are a help and not a hindrance to the jewelry industry, and put the real challenge at getting Gen Z into jewellery stores to buy anything at all.
He also noted that consumers keep walking in to buy the category with no macro marketing behind it.
Both of those can be true while the price series above keeps sliding, because they measure different things: he is describing footfall and this desk is describing what happens to a manufactured product's price once footfall arrives and supply is unconstrained.
The story so far
Go deeper
Method
All four describe a one-carat round lab-grown diamond. The top and bottom are the ends of the range the $705 average is drawn from, read 17 August 2026. The $550 is this paper's own price list of 25 July from a six-retailer sample; CaratRadar's average is 28.2% above it, this desk's arithmetic, and the divergence is disclosed rather than resolved.
Sources
- Lab-grown diamond prices, one-carat reference, read 17 August 2026 — CaratRadar
- The Natural Diamond Price List (as of 30 July 2026) — Carat Capital
- GDTO's Hurwitz: the real industry challenge is Gen Z, not defeating lab-grown — JCK (14 August 2026)
- The one-carat stops falling — Carat Capital (4 August 2026)