GURU DIAM LAB-GROWN PRICE INDEX · Q4 2026 · PUBLISHED 15 OCTOBER 2026
Lab-grown diamond prices per carat: key findings for Q4 2026
Certified round lab-grown diamonds from 1 to 2 carats trade at roughly $75 to $100 per carat at wholesale, and rounds above 2 carats at $100 to $125 per carat. Antique cuts such as old miner, criss cut, kite and hexagon trade at $275 to $375 per carat, about three to four times the round price for the same weight. Classic fancy shapes (oval, emerald, pear, radiant, cushion, princess) sit close to rounds at $100 to $150 per carat. Size matters less than shape: a 5 carat round costs only about a quarter more per carat than a 1 carat round. In lab-grown melee, the smallest sizes cost the most per carat, with 0.70 to 1.40 mm parcels at $75 to $200 per carat against $50 to $75 for 2.00 to 3.25 mm. Color matters less than shape: D–E and F–G rounds trade in the same per-carat band at most sizes, and D–E fancy shapes only pull ahead from 3 carats up. These are trade wholesale indications from Guru Diam's live inventory, not retail prices.
Guru Diam starting prices (October 2026): rounds from $75/ct, fancy shapes from $80/ct, antique cuts from $150/ct, melee from $50/ct, fancy color melee from $150/ct and matched pairs from $120/ct. The index below shows typical wholesale ranges across our inventory.
How lab-grown diamond prices compare by cut family
| Cut family | Trade price per carat (middle 50%) | What drives it |
|---|---|---|
| Round brilliant | $75 – $100 | The most produced cut; prices are tight and competitive |
| Fancy shapes | $100 – $325 | Wide spread: classic shapes near round, specialty shapes much higher |
| Antique cuts | $275 – $375 | Hand-finished faceting, lower yield from the rough, limited supply |
Lab-grown diamond price per carat by size
| Size | Round | Fancy shapes | Antique cuts |
|---|---|---|---|
| 1.00 – 1.49 ct | $75 – $100 | $100 – $250 | $250 – $375 |
| 1.50 – 1.99 ct | $75 – $100 | $100 – $250 | $300 – $375 |
| 2.00 – 2.99 ct | $100 – $125 | $125 – $300 | $250 – $350 |
| 3.00 – 4.99 ct | $100 – $125 | $175 – $350 | $275 – $375 |
| 5.00 ct and up | $100 – $125 | $150 – $425 | $350 – $450 |
Per-carat prices climb only slowly with size in lab-grown, unlike mined diamonds, where the per-carat price jumps at each carat milestone. For rounds the step from 1 carat to 5 carats adds roughly $25 per carat. The bigger jumps come from shape and cut style.
Lab-grown diamond price per carat by shape
| Shape | Trade price per carat (middle 50%) |
|---|---|
| Round | $75 – $100 |
| Oval, emerald, pear, princess, cushion, heart | $100 – $125 |
| Radiant, asscher, marquise | $100 – $150 |
| Trillion | $200 – $325 |
| Moval | $200 – $350 |
| Old miner (elongated), hexagon | $275 – $375 |
| Criss cut, kite | $300 – $375 |
Specialty and antique shapes hold their price because fewer cutters make them well and each one takes more time on the wheel. For jewelers, that is the margin opportunity: a certified old miner lab-grown diamond or a hexagon centre still reads as rare to a retail customer. Browse every shape in our guide to diamond shapes and cuts.
Lab-grown diamond price per carat by color
| Size | Round D–E | Round F–G | Fancy shapes D–E | Fancy shapes F–G |
|---|---|---|---|---|
| 1.00 – 1.49 ct | $75 – $100 | $75 – $100 | $100 – $250 | $100 – $350 |
| 1.50 – 1.99 ct | $75 – $100 | $75 – $100 | $100 – $250 | $100 – $125 |
| 2.00 – 2.99 ct | $100 – $125 | $75 – $100 | $125 – $300 | $100 – $300 |
| 3.00 – 4.99 ct | $100 – $125 | $100 – $125 | $200 – $350 | $125 – $350 |
| 5.00 ct and up | $100 – $125 | n/a | $225 – $450 | $125 – $350 |
Color moves lab-grown prices much less than shape. D–E and F–G rounds share the same $75 to $125 per carat band at almost every size, so dropping a color grade saves little on a round. In fancy shapes, D–E holds a clear premium from 3 carats up ($200 to $450 per carat against $125 to $350 for F–G); below that, the ranges mostly reflect which shapes sit in each group. Fancy shapes here exclude antique cuts, and H color is too thin in our inventory to report.
Lab-grown melee diamond price per carat by mm size
| Round melee size | Trade price per carat |
|---|---|
| 0.70 – 1.40 mm | $75 – $200 |
| 1.50 – 1.95 mm | $75 – $100 |
| 2.00 – 2.55 mm | $50 – $75 |
| 2.60 – 3.25 mm | $50 – $75 |
| 3.30 mm and up | $50 – $125 |
The smallest melee costs the most per carat because cutting and sorting a tiny diamond takes about as much labour as a larger one. If a design allows 2.0 mm instead of 1.2 mm accents, the per-carat cost can roughly halve. See sizes and carat weights in our melee diamond guide or browse wholesale lab-grown melee.
What this means for jewelers buying lab-grown diamonds
- Rounds are a price race. Margins on round centres are thin across the trade; compete on service, speed and certification rather than price alone.
- Shape is where value sits. Antique and specialty shapes earn three to four times the per-carat price of a round of the same size.
- Size up the centre, not the bill. Moving a customer from 1.5 to 2.5 carats adds little per carat in lab-grown.
- Design melee around 2 mm. Very small accent diamonds cost the most per carat.
For pricing on specific diamonds, open a free Guru Diam trade account or browse certified lab-grown diamonds and wholesale diamonds. More price guides: diamond prices and size charts.
Methodology
- Source: Guru Diam's live trade inventory in New York and Los Angeles, as of 15 October 2026. The certified sample covers 5,000+ IGI- and GIA-certified white lab-grown diamonds (D to H colour, mostly VVS and VS clarity); the melee sample covers round lab-grown parcels graded E–F, VVS2–VS1.
- Measure: the trade asking price per carat. Ranges show the middle 50% of inventory in each group (25th to 75th percentile), rounded to the nearest $25. Groups with fewer than 15 diamonds are left out.
- What it is not: these are wholesale indications for the trade, not quotes and not retail prices. Individual diamonds vary with cut quality, measurements and certificate details.
- Trend: this is the baseline quarter. The next index (Q1 2027) will show the change against these figures.
Cite this data: Source: Guru Diam Lab-Grown Price Index, Q4 2026, gurudiam.com. Journalists and researchers are welcome to use these figures with a link to this page. For questions, contact info@gurudiam.com.
Frequently asked questions
How much does a lab-grown diamond cost per carat at wholesale?
In Q4 2026, certified round lab-grown diamonds from 1 to 2 carats trade at about $75 to $100 per carat at wholesale. Fancy shapes run from $100 to $325 per carat and antique cuts from $275 to $375 per carat.
Why are antique cut lab-grown diamonds more expensive?
Antique cuts such as old miner, criss cut and kite take longer to cut, lose more rough in the process and are made by fewer cutters, so they trade at three to four times the per-carat price of a round.
Do bigger lab-grown diamonds cost more per carat?
Only a little. A 5 carat round lab-grown diamond costs roughly $25 more per carat than a 1 carat round at wholesale, far smaller than the size premium in mined diamonds.
Why does small melee cost more per carat?
Cutting and sorting a 1 mm diamond takes nearly as much work as a 2 mm one, so the per-carat price of the smallest melee ($75 to $200) is higher than 2 to 3 mm melee ($50 to $75).
Does color change lab-grown diamond prices?
Less than you might expect. At wholesale, D–E and F–G round lab-grown diamonds trade in the same $75 to $125 per carat band at most sizes from 1 to 5 carats. In fancy shapes, D–E carries a clear premium from 3 carats up. Shape and cut style move the price far more than color.
How often is the Guru Diam Lab-Grown Price Index updated?
Every quarter. Q4 2026 is the first edition and sets the baseline; Q1 2027 will add quarter-on-quarter changes.
