The lowest asking price for a round lab-grown diamond from 1.00 to 1.50 ct, colour F to G, clarity VS1 to VS2, with an IGI report, read at Ritani, Clean Origin, Brilliant Earth, Whiteflash and Blue Nile on 23 October 2026. The same spec, 2.7 times the price from cheapest to dearest.
Maison Assay finding
On 23 October 2026, the cheapest round lab-grown diamond matching one spec (1.00 to 1.50 ct, F to G, VS1 to VS2, IGI report) was $240 at Ritani and $656 at Blue Nile: 2.7 times as much. Per carat the gap is 2.2 times ($238 to $525). All five stones carry an IGI report and the cut label Ideal.
For this spec on 23 October 2026, from $240 to $656 for stones of 1.00 to 1.25 carats, which works out to $238 to $525 per carat. These are asking prices on each jeweler's own page, not a market average and not a recommendation to buy from any of them.
In short:
| Jeweler | Carat | Cut label | Colour, clarity | IGI report | Asking price | Per carat |
|---|---|---|---|---|---|---|
| Ritani | 1.01 | Ideal | G, VS2 | LG843658875 | $240 | $238 |
| Clean Origin | 1.15 | Ideal | F, VS2 | not captured | $360 | $313 |
| Brilliant Earth | 1.00 | Ideal | G, VS2 | not captured | $480 | $480 |
| Whiteflash | 1.10 | Ideal | F, VS1 | LG812646398 | $538 | $489 |
| Blue Nile | 1.25 | Ideal | F, VS1 | not captured | $656 | $525 |
Because the cheapest matching stone is a different weight at each jeweler: 1.00 ct at one and 1.25 ct at another. Price per carat is a better yardstick across weights, though not a perfect one, since a diamond's price per carat is not constant as weight rises. On the chart, each dashed line is one price per carat; a stone's position against the lines is what it costs per carat, whatever its weight.
Very different numbers, which matters because a jeweler's cheapest match is the minimum of however many stones it lists. Brilliant Earth's filter reported 1,320 matches; Whiteflash showed three. Ritani's page did not state a filtered count, so it is shown as not counted rather than guessed.
No. Every figure is the price printed on the listing. On the same visits we saw offers that could lower the amount paid: Ritani's header banner offered 30% off lab-grown diamonds and engagement rings with a code; Clean Origin's listing showed a new-customer welcome price of $288 against its $360 listed price; Brilliant Earth's banner offered a $250 gift card with a purchase over $1,000; Whiteflash's pop-up offered $100 off a first order with a $2,000 minimum; Blue Nile's banner said up to 30% off select styles. We did not apply any code, so we do not know which would apply to a loose diamond, and the order of the five could change once they do.
No, and the reports are the reason. All five stones are IGI-reported and all five jewelers label them Ideal, yet Ritani priced its stone at $240 and Blue Nile priced its at $656. We read the report number from the listing text for Ritani and Whiteflash; for the other three it was an image, a link or not captured, and IGI's own report check sat behind a bot challenge we did not bypass. So we did not verify any report against IGI. For how differently the same cut word can be defined, read Super Ideal against the IGI report. For what each jeweler promises after the sale, see the return and resize policies side by side.
Lab-grown diamonds are diamonds; the FTC's Jewelry Guides require a clear disclosure when a stone is laboratory-grown (16 CFR 23.25), and each listing here states it.
Open the listing, find the IGI report number, and confirm it on IGI's own report check, in your browser, before you pay. A lower price is a lower asking price for a different stone: two stones of the same carat, colour, clarity and cut label can still differ in the proportions and the inclusions the report records. Ask the jeweler in writing what its cut label means before you compare labels across shops.
On 23 October 2026, in a desktop browser, we opened each jeweler's own lab-grown diamond search and set the same filters: round, 1.00 to 1.50 carat, colour F to G, clarity VS1 to VS2. We sorted by price low to high where the page offered it (Ritani, Clean Origin, Brilliant Earth) and read the first listing that matched; where it did not (Whiteflash, Blue Nile) we read every matching stone. We did not filter by laboratory, and at each jeweler the cheapest stone found was IGI-reported, so the IGI condition did not change any result. We noted the cheapest stone's weight, cut label, colour, clarity, lab, report number where shown, and price from its listing, with no code applied. We did not buy, bid or contact any jeweler. Prices and stock change daily, so this is one day's read of one spec, not an index; the next read is January 2027 (quarterly). Raw reads are held in this property's dataset registry, and every number on the page is computed from them.
For one spec, a round lab-grown diamond from 1.00 to 1.50 ct, colour F to G, clarity VS1 to VS2 with an IGI report, the cheapest asking price at five jewelers on 23 October 2026 ranged from $240 to $656, or $238 to $525 per carat. These are listed prices before any code.
For this spec on 23 October 2026, Ritani listed the cheapest matching stone at $240 (1.01 ct, G, VS2, Ideal). That is one day and one spec, not a ranking of jewelers, and the stones are not identical.
No. In this basket the price per carat of the cheapest matching stone differed by a factor of 2.2 across five jewelers, although all five stones carry an IGI report and the cut label Ideal.
No. They are the prices printed on each listing on 23 October 2026. Several jewelers showed codes or sign-up offers that were not applied, so the order of the five could change after a code.
The cheapest matching stone was a different weight at each jeweler, from 1.00 to 1.25 ct. Price per carat lets different weights be set side by side, though it is not a perfect yardstick because price per carat usually changes with weight.
Quarterly. It was read on 23 October 2026 and is next due January 2027. Each update repeats the same spec so the changes are the finding.