The price of a lab-grown diamond is the single fact that most changes how the rest of this timeline reads. The brands of 2015–18 launched into a market where a lab-grown stone cost a little less than a mined one. By 2025 it cost a small fraction. Below are the figures this record can source, with the analyst or publication named for each, and the reasons the numbers sometimes disagree.
The headline figures
| Measure | From | To | Change | Source |
|---|---|---|---|---|
| Lab-grown discount to natural (like-for-like) | ~10% (2016) | ~80% (end 2022) | Gap widened 8× | Zimnisky 1 |
| Average one-carat lab-grown price | US$3,410 (2020) | US$892 (Jan 2025) | −74% | Fortune, citing industry data 4 |
| Wholesale lab-grown prices | 2015 | early 2025 | −90% to −95% | Zimnisky 5 |
| Wholesale since Lightbox launch | US$800/ct (2018) | 2025 | ~−90% | De Beers 6 |
| Wholesale, 2025 alone | Jan 2025 | Dec 2025 | −26% | Golan 7 |
| Lightbox retail, DEF colour | US$1,500/ct | US$900/ct (May 2024) | −40% | Lightbox 3 |
2016–2022: from near-parity to an 80% discount
Paul Zimnisky's analysis is the most cited long-run series. As recently as 2016, he notes, lab-grown diamonds sold for only about 10% less than equivalent natural stones. By the end of 2022 the discount had reached roughly 80%. Over 2022 alone like-for-like prices fell an estimated 20% while demand grew 38% to about US$12 billion and lab-grown passed 10% of global diamond jewellery sales for the first time 1.
The cause was supply. CVD reactors that cost up to US$300,000 in 2019 were selling for under US$100,000 in India by 2022, and India and China together accounted for nearly three-quarters of lab-grown jewellery production by volume 1. Signet and Pandora expanded distribution the same year, so volume and price moved in opposite directions at once.
2023: the wholesale–retail gap
By late 2023 the wholesale collapse had outrun retail. On 21 November 2023 the Rapaport Group issued a consumer alert showing an identical three-carat round near-colourless lab-grown solitaire at US$2,975 from one retailer and US$8,190 from another, a 275% difference, and said some lab-grown stones were trading as low as 99% below natural at wholesale while "certain retailers are not passing these savings onto consumers". Martin Rapaport predicted wholesale prices would settle at US$50 to US$80 per carat 2. De Beers ended Lightbox's engagement-ring trial in September 2023, citing the volumes needed to make it viable 2.
2024: Lightbox cuts, then exits
Lightbox had launched in 2018 at a flat US$800 per carat, deliberately far below the market 8. On 10 May 2024 it cut prices by up to 40%: colourless DEF stones from US$1,500 to US$900 per carat, GH from US$800 to US$600, IJ from US$800 to US$500 3. The price De Beers had been criticised for setting too low in 2018 was now above the market.
January–March 2025: the numbers at the bottom
Fortune's January 2025 survey put the average one-carat lab-grown price at US$892, down from US$3,410, a fall of 74% against 2020 prices, while natural diamonds were down 26% over two years 4. In March 2025 Zimnisky told JCK that "at wholesale, lab-grown prices are down 90% to 95% compared with prices in 2015", that Indian producers were making diamonds for under US$10 per rough carat, and that he expected lab-grown to migrate to e-commerce at very low price points within five years 5.
On 8 May 2025 De Beers announced it would close Lightbox, stating that wholesale lab-grown prices had fallen around 90% since the 2018 launch and were "tracking closer to a cost-plus model" 6. The full story is on the De Beers page.
2025: a slower fall, and the first rises
Edahn Golan's Lab Diamond Wholesale Price List recorded a 26% fall across 2025, but the fourth-quarter decline was 4.7%, which Golan called the smallest since lab-grown entered the market. The decline was uneven by size: three-carat rounds fell 32% over the year, while 1.5-carat stones fell only 8% and rose 11% quarter on quarter. The reason was cost: Chinese HPHT factories stopped cutting once rough reached about US$10 per carat, and goods of one carat and below began to rise 7. Golan's outlook was for smaller stones to keep firming and larger ones to level rather than recover.
Why the figures differ
Readers will see 74%, 85%, 90% and 95% quoted as "the" fall. They are all sourced; they measure different things.
- Wholesale versus retail. Wholesale fell furthest. Retail fell less because retailers kept margin, which is what the Rapaport alert was about 2.
- Start date. "Since 2015" (Zimnisky) gives 90–95%; "since 2020" (Fortune) gives 74%; "since 2018" (De Beers) gives about 90%.
- Like-for-like or average. A like-for-like series tracks a fixed quality; an average-ticket series also reflects shoppers buying bigger stones as prices fall.
- Size. From 2025 small and large stones diverged, so a single percentage is increasingly misleading 7.
What it means for the history
The brands on this timeline launched at very different points on that curve. MiaDonna and Ada sold lab-grown at near-natural prices; Courbet, Lark & Berry and Lightbox launched in 2018 when the discount was still modest; Pandora arrived in 2021 just before the steep part. Anyone reading "lab-grown was cheap" back into 2018 is reading history backwards. For buyers, the practical consequences, what a UK price should look like now and how to judge a retailer's margin, are covered in the UK buying guide.