Rings.com Research
Lab-Grown Diamond Price Index
Monthly benchmark prices for lab-grown diamonds across major U.S. online retailers.
Published May 21, 2026 · E VS1 Round Excellent IGI · USD
At 1ct, prices range from $290 to $901 depending on where you buy. At 2ct, the gap widens to $566 to $3,284. Same certification. Same grade. Different retailer.
| Retailer | 1ct | 1.5ct | 2ct |
|---|---|---|---|
| Ritani * | $290 | $392 | $566 |
| Clean Origin | — | $902 | $1,242 |
| Grown Brilliance | $610 | $1,199 | $1,656 |
| With Clarity | $595 | $1,025 | $1,440 |
| James Allen | $646 | $1,176 | $1,882 |
| Blue Nile | $711 | $1,295 | $2,070 |
| Brilliant Earth | $901 | $1,638 | $3,284 |
| VRAI (non-IGI) | $1,180 | $1,071 | — |
| Market Median (IGI retailers) | $628 | $1,176 | $1,656 |
Total stone price. E VS1 Round Excellent IGI. Median. All prices USD. VRAI: proprietary Diamond Foundry grading, not matched to E VS1 IGI specification. * Largest month-over-month move. See Key Findings.
Eight retailers. 528,819 listings. E VS1 Round Excellent IGI.
- If you're shopping for a 1ct E VS1 IGI round, prices range from $290 to $901 depending on where you buy. That gap is not a quality difference. It's a retailer difference.
- Ritani posted the largest month-over-month move: -28% at 1ct ($401 to $290), -37% at 1.5ct, -32% at 2ct. Sample sizes of 843-1,707 qualifying stones per cell confirm this is not a data artifact.
- Prices across most retailers were stable month-over-month. The Ritani move is the outlier.
- Clean Origin inventory contracted from ~16,000 to ~6,500 listings. Its 1ct cell has no qualifying data this month.
- James Allen (now merged into Blue Nile): $646 at 1ct, $1,882 at 2ct.
Methodology
Scope. This index tracks listed retail prices (not transaction prices) across major U.S. online lab-grown diamond retailers. The May 2026 edition analyzed 528,819 lab-grown diamond listings across eight retailers. Data was collected on May 18, 2026.
Retailer panel. This edition tracks eight retailers: Ritani, Grown Brilliance, With Clarity, James Allen, Blue Nile, Brilliant Earth, Clean Origin, and VRAI. The panel is fixed and disclosed for comparability. Any additions, removals, or reclassifications will be explicitly noted in that month's report.
Price inputs. Prices are the publicly visible list price at the time of data collection, including any site-wide or automatic reductions that do not require a membership or promotional code. Excluded: promotional codes, membership discounts, negotiated pricing, strikethrough compare-at prices. All prices in USD, excluding sales tax and shipping.
Benchmark specification. E color, VS1 clarity, round brilliant, Excellent cut, IGI-certified. Three weight cells: 1ct (0.95-1.05ct), 1.5ct (1.45-1.55ct), and 2ct (1.95-2.05ct).
Statistical method. Each published figure is the median total stone price across all qualifying listings within that cell. A minimum of 30 qualifying listings is required for publication. Per-cell sample sizes (n) are visible as tooltips when hovering over any price. Clean Origin 1ct has no qualifying data this month. VRAI 2ct (n=22) falls below the threshold and is not published.
Deduplication. Listings are deduplicated within each retailer by URL. Stones with identical IGI certificate numbers may appear at more than one retailer and are counted as independent listings at each retailer where they appear.
VRAI. VRAI uses Diamond Foundry proprietary grading exclusively and carries no IGI-certified inventory. Included as a non-comparable reference point. Weight windows: 1ct = 1.0-1.09ct (D-F colors); 1.5ct = 1.6-1.9ct (D-G colors). VRAI 2ct fell below the 30-listing minimum in May and is not published.
James Allen. Tracked as an independent storefront through its active period. Signet Jewelers announced in March 2026 that the James Allen banner will be shuttered by mid-2026, with inventory transitioning to Blue Nile. The jamesallen.com storefront now redirects to Blue Nile. Rings.com will assess whether the James Allen API remains active before the June edition.
Comparability. Historical index figures may not be directly comparable when the benchmark specification or retailer panel changes. Such changes are explicitly noted in the relevant month's report.
Independence. Rings.com receives no compensation from the retailers included in this index for inclusion or ranking, and no retailer has any editorial control over the methodology or results.