Rings.com Research & Data

Rings.com Research

Lab Grown Diamond Price Per Carat

As of September 2026, a 1 carat E VS1 IGI round lab-grown diamond lists at a Market Median of $571 across four U.S. retailers, the first published 1ct Market Median since June; 1ct retailer medians run from $281 to $796.

Data as of September 18, 2026. Updated monthly. Next edition: week of October 26, 2026.

Published September 18, 2026  ·  E VS1 Round Excellent IGI  ·  USD  ·  The Rings.com Lab-Grown Diamond Price Index

$571Market Median, 1ct E VS1 IGI
$281 to $7961ct retailer medians, 4 published
$558 to $2,7562ct retailer medians, 6 published
251,098listings, seven retailers, September 17, 2026
Key figures in words, September 2026 (for quoting)
  • In September 2026 the Market Median for a 1 carat E VS1 IGI round lab-grown diamond was $571 across four U.S. retailers (Ritani, Grown Brilliance, With Clarity, Brilliant Earth), the first 1ct Market Median published since June 2026.
  • In September 2026 a 1 carat E VS1 IGI round lab-grown diamond listed at retailer medians from $281 to $796 among IGI-panel retailers, and $1,583 at VRAI, a non-IGI reference retailer.
  • The September 2026 edition of the Rings.com Lab-Grown Diamond Price Index analyzed 251,098 lab-grown diamond listings collected from seven U.S. online retailers on September 17, 2026.
  • Ritani raised its E VS1 IGI round medians across all three tracked weights in September 2026: +26% at 1ct ($223 to $281), +20% at 1.5ct ($212 to $254), and +18% at 2ct ($248 to $292), reversing August's decline.
  • Brilliant Earth's 1.5ct E VS1 IGI round median fell 32% in September 2026, from $1,151 to $784 per carat, while its 1ct (-7%) and 2ct (+1%) medians moved far less, the panel's largest single-cell move this edition.

Cite as: Rings.com Lab-Grown Diamond Price Index, September 2026 edition, rings.com/pages/lab-grown-diamond-price-index.

At 1ct, prices range from $281 to $796 depending on where you buy. At 2ct, the gap widens to $558 to $2,756. Same certification. Same grade. Different retailer.

Retailer 1ct 1.5ct 2ct
Ritani *$281$381$584
Clean Origin—$395$558
Grown Brilliance$500$972$1,356
With Clarity$642$1,067$1,472
Blue Nile—$1,004$1,640
Brilliant Earth$796$1,176$2,756
VRAI (non-IGI)$1,583$2,145 †—
Market Median (IGI retailers) $571——

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 this edition, at 1.5ct. See Key Findings. † VRAI's 1.5ct cell covers a 1.6–1.9ct window (median actual weight 1.75ct, not 1.5ct) and is not directly comparable to the other retailers in that column; see the VRAI methodology note. A dash (—) means fewer than 30 qualifying listings; in the Market Median row it means the median is not published this edition (the 1.5ct and 2ct cells fail this edition's publication rule; see Key Findings and the Market Median methodology note).

Key Findings: September 2026

Seven retailers. 251,098 listings. E VS1 Round Excellent IGI.

Ritani reversed course, raising prices at every tracked weight.
Its 1ct median rose from $223 to $281 per carat (+26%), 1.5ct from $212 to $254 (+20%), and 2ct from $248 to $292 (+18%), the opposite direction from August's decline across the same three cells. The 1ct sample fell from 1,126 stones to 504 and 1.5ct from 1,394 to 975, while Ritani's overall September collection (78,635 rows) was within 5% of August's (81,986), so the sample drop is concentrated in this specific carat/color/clarity/cut cell, not a smaller overall collection.
Brilliant Earth's 1.5ct cell dropped 32%, the panel's largest single-cell move this edition.
Its 1.5ct median fell from $1,151 to $784 per carat; by contrast its 1ct median moved -7% ($856 to $796) and 2ct +1% ($1,365 to $1,378). This was checked against the underlying listings (216 distinct URLs, prices $840-$1,810, a normal-looking distribution for the cell) rather than taken as a possible collection artifact.
Grown Brilliance held its 1ct and 1.5ct medians exactly flat while its listed inventory fell.
The 1ct sample dropped from 795 to 435 stones (median unchanged at $500/ct) and 1.5ct held at 371 to 376 stones (median unchanged at $648/ct); 2ct rose 3% ($659 to $678/ct) on a smaller sample too, 920 stones to 530. None of the three cells moved by more than 3%, the most stable retailer on the panel this edition despite the inventory swings.
Blue Nile's IGI cells returned at 1.5ct and 2ct, retiring the GIA reference row used the last two editions.
Its E VS1 IGI round cells cleared the 30-listing minimum at 1.5ct (n=56, $669/ct) and 2ct (n=54, $820/ct) for the first time since June; 1ct remains thin (n=27). Because Blue Nile's own IGI series is available again for most cells, the separate Blue Nile (GIA) reference row shown in July and August (used only when IGI cells were unpublishable) does not appear this edition; it returns if Blue Nile's IGI cells thin again.
VRAI's inventory was completely repriced-flat this cycle, a sharp reversal from August's +76% same-lot jump.
Of 690 listings present in both the August 29 and September 17 collections (matched by product URL), every single one carries an identical price to the cent. VRAI's published cells land at $1,583/ct (1ct, n=36) and a $2,145 median total stone price (1.5ct window, n=92; see the VRAI methodology note on why this cell uses the raw median rather than ppc x weight); its 2ct cell (n=11) remains below the minimum.
Clean Origin's 1.5ct cell recovered above the minimum; its 1ct cell has not.
1.5ct held n=210 this edition (was thin at n=24 in August), publishing at $263/ct; 2ct held roughly flat, $279/ct (n=197) against $278/ct (n=187) in August. The 1ct cell remains thin (n=20, was n=1 in August): still far short of the 30-listing minimum despite the partial recovery elsewhere in the panel.
The 1ct Market Median returns after two editions withheld: $571, from Ritani, Grown Brilliance, With Clarity, and Brilliant Earth.
The same four retailers were the only ones with a published 1ct figure in both August and September, so the contributor-eligibility test passes; because August itself withheld its 1ct Market Median, there is no prior published figure to test the move against, so this edition's figure is published as newly re-established rather than compared to a withheld prior value. 1.5ct and 2ct are withheld this edition: Blue Nile's newly-published cells (both weights) and Clean Origin's newly-published 1.5ct cell were not part of either cell's published contributor set in August, so the rule's contributor-eligibility test fails for both, exactly the composition-change case the rule exists to catch. See the Market Median methodology note.
With Clarity's collection was a full capture on all three bands, the first time since June.
All three cells now report a complete count rather than a partial-capture floor: 1ct $642/ct (n=453), 1.5ct $711/ct (n=997, +2.9% from August's disclosed 85%-capture floor of $691), 2ct $736/ct (n=300, +6.1% from $694). Because August's 1.5ct figure was itself a floor, some or all of this edition's 1.5ct increase may reflect the removal of that floor rather than a price move; this index cannot separate the two from the data available.

Methodology

Scope.
This index tracks listed retail prices (not transaction prices) across major U.S. online lab-grown diamond retailers. The September 2026 edition analyzed 251,098 lab-grown diamond listings across seven retailers. Data was collected on September 17, 2026 (With Clarity in three supplemental pulls the same evening, Pacific time; see Coverage this edition).
Retailer panel.
This edition tracks seven retailers: Ritani, Clean Origin, Grown Brilliance, With Clarity, Blue Nile, Brilliant Earth, 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. Total Stone Price figures in the price table (all cells except VRAI's 1.5ct, corrected in the VRAI note below) are computed as the median price-per-carat for that cell multiplied by the cell's nominal carat weight, not the raw median of actual listing prices; the two differ by up to a few percent (this edition, between 0% and 2.6% across the published IGI cells, the largest gap being Blue Nile's 1.5ct cell, $1,004 published against a raw median of $1,031). This is a candidate for a deliberate, disclosed methodology change in a future edition, not something being silently recomputed now. Clean Origin 1ct (n=20) falls below the threshold and is not published. Blue Nile 1ct (n=27) falls below the threshold and is not published. VRAI 2ct (n=11) falls below the threshold and is not published.
Coverage this edition: Ritani and Grown Brilliance.
Both continue to be scraped within three fixed carat bands (0.95-1.09ct, 1.40-1.59ct, 1.90-2.09ct, all colors), the collection method adopted in July. Ritani's September collection (78,635 rows) was within 5% of August's (81,986), so the overall capture is comparable; its E VS1 IGI round 1ct sample fell from 1,126 to 504 stones and 1.5ct from 1,394 to 975, a shift concentrated in this specific spec, not a smaller overall collection. Ritani's prices rose at every tracked weight this edition (see Key Findings). Grown Brilliance's 1ct sample fell from 795 to 435 stones and 2ct from 920 to 530, while its medians held flat to within 3% at every weight; its 1ct figure continues to cover 1.00-1.05ct (no listings returned between 0.95 and 0.99ct this edition either).
Coverage this edition: With Clarity.
With Clarity's benchmark-band collection was a full capture on all three bands this edition (1ct n=453, 1.5ct n=997, 2ct n=300), the first time since June that no band required a supplemental mobile-network pull; see the July and August editions for the capture method used when the site blocks the collecting IP. Because August's 1.5ct figure ($691/ct) was disclosed as an 85%-capture floor, part of this edition's 1.5ct increase to $711/ct may reflect the removal of that floor rather than a price move; the data available cannot separate the two effects. With Clarity is included in every Market Median computation and price range on this page.
Coverage this edition: Clean Origin and Blue Nile.
Clean Origin's 1.5ct cell recovered above the 30-listing minimum this edition (n=210, was n=24 in August), publishing at $263/ct; its 2ct cell held roughly flat ($279/ct, n=197, against $278/ct, n=187, in August). Its 1ct cell remains thin (n=20): still short of the minimum despite the partial recovery elsewhere. Blue Nile's E VS1 IGI round cells cleared the minimum at 1.5ct (n=56, $669/ct) and 2ct (n=54, $820/ct) for the first time since June; its 1ct cell remains thin (n=27, was n=18 in August). Because Blue Nile's own IGI series is available again for most cells, the separate Blue Nile (GIA) reference row used in July and August is retired this edition; it returns if Blue Nile's IGI cells thin again. No Blue Nile GIA row is shown this edition.
Coverage this edition: what is published at 1ct.
Four of the six IGI retailers have a published 1ct figure this month (Ritani, Grown Brilliance, With Clarity, Brilliant Earth), the same four as August; July's 1ct set was different (Ritani, Clean Origin, With Clarity, Brilliant Earth published; Grown Brilliance and Blue Nile thin), which is exactly why the Market Median could not test this edition's move against a July baseline and instead publishes as newly re-established (see the Market Median entry). Six IGI retailers have a published 1.5ct figure and six have a published 2ct figure this month, matching July's coverage at those cells (July also had all six); neither the 1.5ct nor the 2ct Market Median is published this edition, see below.
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.
Market Median.
Computed as the median of the per-retailer median prices per carat across all IGI-panel retailers with qualifying (published) data in that cell, rounded, then multiplied by the cell's nominal weight. VRAI is excluded from this computation (non-IGI, non-comparable). Publication rule, applied from the August edition: a cell's Market Median is published only when every retailer contributing to it also had a published figure in that cell in the prior edition, and the blended month-over-month move agrees with the move of those same retailers to within five percentage points; otherwise the blended figure mostly measures who is in the panel and is withheld. 1ct passes the first test: the same four retailers (Ritani, Grown Brilliance, With Clarity, Brilliant Earth) were the only ones with a published 1ct figure in both August and September. Because August itself withheld its 1ct Market Median, there is no prior published figure to test the move against; this edition's figure, $571, is published as newly re-established rather than compared to a withheld prior value, and is the first published 1ct Market Median since June. 1.5ct and 2ct both fail the first test: Blue Nile (both cells) and Clean Origin (1.5ct only) newly cleared the publication minimum this edition and were not part of either cell's published contributor set in August, so a blended figure this month would mostly measure the panel gaining retailers, not a price move; both are withheld. The published per-retailer figures are shown individually in the price table instead.
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); 2ct = 2.1-2.45ct (D-G colors). VRAI's 1ct (n=36) and 1.5ct (n=92) cells are published this edition; its 2ct cell (n=11) is not. The 1ct figure is median $/ct x 1 ($1,583; the raw median listing price in that window is $1,650). Because VRAI's 1.5ct window (median actual weight 1.75ct) diverges substantially from the nominal 1.5ct label, its published Total Stone Price figure ($2,145) is the true median of actual listing prices for this cell, not median $/ct ($1,250) x 1.5. VRAI's pricing was completely unchanged this cycle: of 690 lots present in both the August 29 and September 17 collections (matched by product URL), every one carries an identical price to the cent, a sharp reversal from August's +76% same-lot repricing against July. This index checked the price fields directly against the raw collections rather than assuming a currency or collection artifact.
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. James Allen was retired from the panel in the June 2026 edition following the closure of its independent storefront. The Ritani and Grown Brilliance carat-band collection is a collection-methodology choice, not a benchmark-specification change; this edition's band request starts at 0.95ct, which brings Ritani's 1ct cell to full coverage and affects its 1ct sample as described above, while Grown Brilliance's 1ct coverage is unchanged at 1.00-1.05ct. With Clarity's 1.5ct figure is a partial capture (85%) this edition, as July's was (74%), and is a floor on the true median; see Coverage this edition.
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.

Retailer selection. Retailers in this index are selected by our research process and are never added by request, payment, or partnership. The full criteria and observation process are public: how retailers are selected for this index.

Previous editions

Each edition is a frozen snapshot: the figures shown there do not change after publication.