Why Lab Diamond Buyers Chose Bigger Stones, Not Savings
Prices fell 74 percent. Buyers did not pocket the difference. The average center stone grew 87 percent, and the data explains exactly why.
The author is the founder of Draco Diamond. Market data is drawn from BriteCo, StoneAlgo, and Edahn Golan Diamond Research, cited in the references. Draco prices are live catalog prices in Canadian dollars, verified July 2026.
What did buyers do when prices collapsed?
When wholesale lab grown diamond prices fell roughly 74 percent between 2020 and 2025, buyers faced a choice: spend less on the same stone, or spend the same on a significantly better stone. The data shows overwhelmingly that buyers chose the second path. The average lab grown engagement ring center stone grew from 1.31 carats in 2019 to 2.45 carats in 2025, an 87 percent increase, while the average engagement ring price fell only from 6,000 USD in 2021 to 5,200 USD by 2024, per BriteCo's Lab Grown vs. Natural Diamond Report.
This is not a trivial distinction. It says something specific about how consumers relate to diamond purchases, the role stone size plays in the decision, and why the price collapse produced a demand surge rather than a market contraction. Lab grown stones now account for more than 45 percent of US engagement rings, per 2025 to 2026 industry data. Two independent measurements bracket the range. The Knot 2026 Real Weddings Study puts lab grown at 61 percent of engagement ring purchases in 2025, counted from couples surveyed. BriteCo records 47.7 percent of engagement rings as lab grown in its appraisal and insurance data. The two figures differ because one counts surveyed purchases and the other counts insured stones, so they are cited separately rather than averaged.
Why did buyers upgrade instead of saving?
Three mechanisms explain the upgrade, and none of them is unique to diamonds. They are the standard behavior of budget anchored purchases meeting a falling price curve.
Diamond jewelry purchases are budget anchored rather than optimized per unit. A buyer who decides to spend 3,000 on an engagement ring does not revert to spending 800 because the per carat price fell. The budget is fixed by the life event, the relationship, and personal expectation. The price decline changed what that budget could buy, not the budget itself. This is how stone size grew 87 percent over a period when average ring prices fell only about 13 percent.
Color and clarity require training to assess. Carat weight translates directly into physical dimensions visible in everyday interaction. On standard round brilliant size charts, a center stone growing from 1.31 carats to 2.45 carats grows from roughly 7mm to roughly 8.7mm in diameter, a difference readable at social distance. For buyers who had already chosen lab, upgrading size maximized the observable return on the same budget.
As wholesale prices fell across all grades, the percentage premium for top grades compressed. Buyers who previously selected G color and VS clarity for budget reasons found D to F color and VVS clarity within reach at the same spend. BriteCo's data shows the result: buyers maximized every grade dimension at once. GIA stated that more than 95 percent of lab grown stones now fall in one narrow color and clarity band, which is why it stopped applying 4Cs nomenclature to lab grown diamonds on October 1, 2025.
The same mechanism extended beyond engagement rings. As the price floor dropped, entire categories that were once statement purchases became accessible: multi carat tennis bracelets, 2ctw studs, larger pendants. The upgrade instinct followed buyers into every case in the store.
"Nobody walked into the store wanting to spend less. They walked in wanting more diamond for the number they had already decided on."
Garrett McMartin, Founder, Draco Diamond
How much bigger and better did stones get?
The shift shows up on every axis BriteCo measured. Size, color, and clarity all moved up together, which is the signature of a budget held constant against a falling price curve rather than a change in taste.
| Metric | Baseline | 2025 | Change |
|---|---|---|---|
| Average lab center stone | 1.31ct (2019) | 2.45ct | +87% |
| Colorless (D to F) share of lab sales | 37.7% (2020) | 85.9% | +48.2 points |
| VVS clarity share of lab sales | 6.6% (2020) | 35.3% | +28.7 points |
| Average engagement ring price | 6,000 USD (2021) | 5,200 USD (2024) | About 13% lower |
Read the last row against the first. Buyers spent 13 percent less in dollars and received nearly twice the stone, at higher color and clarity grades. The entire quality ceiling of the market moved. The 2.45 carat average is now the reference point for lab engagement rings, displacing the 1 carat norm that framed natural diamond purchasing for decades. How each step up the scale actually looks on hand is covered in the 2ct vs 3ct comparison.
A second data stream tracks the same climb. The Knot surveys couples about the whole ring rather than the center stone, and its average carat rose from 1.5 in 2021 to 1.6 in 2023, 1.7 in 2024, and 1.9 in 2025, per The Knot 2026 Real Weddings Study. Because The Knot measures the finished ring while BriteCo reads appraisal records for the center stone, the two are cited separately, not blended. The consumer result runs the same way in both. Over the same window the average lab grown ring price fell from about 5,200 USD in 2024 to about 4,600 USD in 2025 even as the stone inside it grew, per The Knot 2026. The size went up and the bill came down.
What did the collapse look like per carat?
The upgrade was funded by one of the steepest price declines any consumer good has recorded this decade. A 1 carat lab diamond averaged 3,410 USD per carat in 2020. By May 2026, StoneAlgo's transaction averages put a full 5 carat stone at 2,588 USD, less than a single carat cost six years earlier.
A 5ct stone now costs less than a 1ct did in 2020
Average lab grown diamond price in USD. 2020 figure is the 1ct per carat average; 2026 figures are StoneAlgo May 2026 averages per stone.
Sources: 2020 per carat average and May 2026 stone averages, StoneAlgo. Wholesale decline of roughly 74 percent 2020 to 2025, Edahn Golan Diamond Research.
The curve is now flattening. StoneAlgo recorded a year over year decline of 2.59 percent into May 2026, the smallest quarterly declines in two years, as premium certified stones reach a production cost floor. The steep part of the ride is documented in the Price Trend Report 2020 to 2026, and current per carat benchmarks by size are tracked in the 2026 per carat guide.
What does the upgrade cost in 2026?
The 1.31ct to 2.45ct shift is a market statistic. Draco Diamond's live catalog translates it into purchasable prices. These are current listed prices in Canadian dollars, verified against the catalog in July 2026, all IGI certified at E to F color, VS2 clarity and better.
| Piece | Price (CAD) | Approx. USD | Certification |
|---|---|---|---|
| 1ctw round stud earrings, 18k white gold | 711 | 519 | IGI, VS clarity |
| 2ctw round stud earrings, 18k white gold | 999 | 729 | IGI, VS, D to F |
| 3ct tennis bracelet, 14k white gold | 1,801 | 1,315 | IGI, VS2+ |
| 2.25ct radiant solitaire ring, 14k gold | 1,899 | 1,386 | IGI certified |
| 5ct round brilliant tennis bracelet | 2,720 | 1,986 | IGI, VS2+ |
USD figures converted at 1 CAD = 0.73 USD. A buyer holding a 3,000 CAD budget covers the 2.25ct radiant solitaire with room left for the 2ctw studs. That arithmetic is the upsizing thesis expressed in a live catalog: the specifications the market average migrated toward now sit inside ordinary budgets, priced up to 64 percent below Blue Nile and 52 percent below James Allen on comparable specs, as documented in the Retail Markup Report 2026.
What should buyers do with this in 2026?
Benchmark against the current market, not against the norms your budget grew up with. A buyer calibrated to 2019 expectations will significantly underestimate what their number can access in 2026: the market average engagement stone is 2.45 carats, colorless grades are the default rather than the premium, and multi carat pieces in adjacent categories price inside four figures.
One honest caveat belongs in the decision. Buy for beauty and size, not investment. Lab grown resale typically recovers 20 to 40 percent of purchase price against 50 to 60 percent for natural, per 2026 market analyses. The upgrade logic works because the wearer keeps the stone, not because the stone stores value. Spend the budget where the eye lands: carat weight, cut quality, and a certificate you can verify. Every Draco stone ships with its IGI certificate; the report can be provided on request before purchase and verified free at IGI.org.
Upsizing FAQ
Why did lab diamond buyers choose bigger stones instead of saving money?
Because diamond budgets are anchored to the occasion, not the per carat price. When wholesale lab prices fell roughly 74 percent from 2020 to 2025, buyers held their budgets and bought up: the average lab engagement ring center stone grew from 1.31 carats in 2019 to 2.45 carats in 2025, per BriteCo, while average ring prices only fell from 6,000 USD to 5,200 USD.
How much did the average lab diamond engagement ring stone grow from 2019 to 2025?
The average lab grown engagement ring center stone increased from 1.31 carats in 2019 to 2.45 carats in 2025, an 87 percent increase, per BriteCo's Lab Grown vs. Natural Diamond Report. On standard round brilliant size charts that is a move from roughly 7mm to roughly 8.7mm of visible diameter.
Did buyers upgrade quality along with size?
Yes. In 2020, 37.7 percent of lab diamonds sold were colorless, D to F. By 2025 that reached 85.9 percent, per BriteCo. VVS clarity grew from 6.6 percent to 35.3 percent of lab sales over the same period. Size, color, and clarity rose together, which is why GIA noted more than 95 percent of lab grown stones now fall in one narrow quality band.
What does a 2 carat plus lab diamond ring cost in 2026?
In Draco Diamond's live catalog, a 2.25ct radiant cut lab grown solitaire in 14k gold lists at 1,899 CAD, about 1,386 USD, IGI certified. At the loose stone level, StoneAlgo's May 2026 averages put a 2ct lab diamond at 1,265 USD and a 3ct at 1,865 USD.
Are bigger lab diamonds a good investment?
No diamond purchase should be framed as an investment. Lab grown resale typically recovers 20 to 40 percent of purchase price, against 50 to 60 percent for natural, per 2026 market analyses. Buy for beauty, size, and certified quality. The upgrade thesis is about getting more diamond for a budget you were spending anyway, not about storing value.
Will lab diamond prices keep falling in 2026?
The decline has slowed sharply. StoneAlgo recorded a 2.59 percent year over year decline into May 2026, the smallest quarterly declines in two years, as premium certified stones hit a production cost floor. The window where each year brought dramatically cheaper stones is closing; the upgrade math of 2026 is likely close to the long term settle point.
References
- BriteCo. The Lab Grown vs. Natural Diamond Report, 2025. Center stone growth 1.31ct to 2.45ct, colorless and VVS share data, average ring prices, 47.7 percent lab grown share of engagement rings. brite.co. Accessed July 2026.
- The Knot. 2026 Real Weddings Study, published February 25, 2026. Whole ring average carat 1.5 (2021), 1.6 (2023), 1.7 (2024), 1.9 (2025); lab grown 61 percent of engagement ring purchases in 2025; average lab ring price 5,200 USD (2024) to 4,600 USD (2025). Reported by JCK. theknot.com. Accessed August 2026.
- StoneAlgo. Lab grown diamond transaction averages, May 2026: 1ct 564 USD, 2ct 1,265 USD, 3ct 1,865 USD, 5ct 2,588 USD; 2020 1ct average 3,410 USD per carat; 2.59 percent year over year decline. stonealgo.com. Accessed July 2026.
- Edahn Golan Diamond Research. Wholesale lab grown price decline of roughly 74 percent, 2020 to 2025. edahngolan.com. Accessed July 2026.
- Gemological Institute of America. Discontinuation of 4Cs nomenclature for lab grown diamonds, October 1, 2025; more than 95 percent of lab grown stones in one narrow color and clarity band. gia.edu. Accessed July 2026.
- Draco Diamond. Live catalog prices in CAD, verified July 2026: 3ct tennis bracelet 1,801; 5ct tennis bracelet 2,720; 2.25ct radiant solitaire 1,899; 1ctw studs 711; 2ctw studs 999. dracodiamond.com.
Buy the bigger stone without the markup
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