Natural Diamonds Slid Again While Lab-Grown Quietly Climbed

Natural diamond prices dropped 6.4% this week across our database of 7.3 million stones, while lab-grown climbed 5.6% across 14.7 million listings. That's a swing of 12 percentage points in seven days. If you're shopping right now, which market you're buying from matters more than almost any other decision you'll make.

The 30 day picture is starker still. Naturals are down 9.5% over the past month. Lab-grown stones are essentially flat, up a negligible 0.14%. What looked like a temporary dip in natural pricing three weeks ago is starting to feel structural.

Where natural prices crumbled

The single biggest category drop was natural round brilliants in the 0.30 to 0.49ct range, N+ colour, I clarity. Down 82.6% in a week. Not a typo. These are low colour, heavily included smalls, and the market has repriced them almost overnight. Over 30 days the decline was 30.9%, meaning the bulk of the damage landed in the past seven days alone.

Larger stones took a beating too. Natural pears in the 5.00 to 9.99ct range, J to K colour, I clarity, fell 48.4%. That category was already down 47.7% over 30 days, so this isn't a blip. It's a sustained correction. Natural ovals in the 4.00 to 4.99ct range with the same colour and clarity profile dropped 40.3%. Natural cushions from 3.00 to 3.99ct, F to G colour, I clarity, lost 39.6%.

Category	Shape	Carats	Colour	7 Day Move	30 Day Move
Natural	Round	0.30 to 0.49	N+	Down 82.6%	Down 30.9%
Natural	Pear	5.00 to 9.99	J to K	Down 48.4%	Down 47.7%
Natural	Pear	0.30 to 0.49	N+	Down 40.5%	Up 6.2%
Natural	Oval	4.00 to 4.99	J to K	Down 40.3%	Down 42.1%
Natural	Cushion	3.00 to 3.99	F to G	Down 39.6%	Down 34.9%

A pattern runs through every row: lower colour grades and included clarity stones are getting punished hardest. If a natural stone isn't reasonably clean and white, buyers don't want it at anywhere near last month's price. Fancy shapes in larger sizes are especially exposed.

Not every natural category fell, though. Natural rounds in D to E colour with I clarity rose 61.7% this week, and natural radiants from 0.30 to 0.49ct in N+ colour jumped 41.0%. Both sit in the I clarity range, which suggests included inventory is being violently repriced in both directions. The market isn't simply punishing I clarity across the board. It's being far more selective, rewarding top colour even in lower clarity while abandoning everything else.

Lab-grown's quiet rally

While naturals bled value, lab-grown stones pushed higher. The standout was lab-grown ovals in the 1.00 to 1.24ct range, J to K colour, I clarity, surging 84.5% in a week and 43.6% over 30 days. An unusual move for a segment that spent most of 2026 grinding sideways.

Lab-grown rounds in the 0.20 to 0.29ct range, D to E colour, I clarity, jumped 53.8%. Small stones with top colour are finding keen buyers willing to pay up.

Supply tells part of the story. Lab-grown round brilliants in the 0.30 to 0.49ct range saw supply explode by 512% this week. Lab-grown rounds from 0.50 to 0.74ct added 178%. Lab-grown ovals in the 1.00 to 1.24ct range grew 128%, with 21 new listings and 12 delisted. That's an enormous wall of new inventory, yet prices still rose. Demand is absorbing the flood. For now.

On the natural side, supply surged too. Natural rounds in the 1.00 to 1.24ct range jumped 419% in available listings, with 24 new stones added and only 12 delisted. Rounds from 1.50 to 1.99ct climbed 225%, with 47 new listings and just 4 removed. Rising supply alongside falling prices suggests sellers are getting nervous. Fresh inventory is hitting the market at exactly the moment buyers are pulling back, and that combination rarely ends well for prices.

The gap between natural and lab-grown

Lab-grown diamonds now cost 72% to 86% less than equivalent natural stones depending on shape. Marquise cuts show the widest spread at 85.8%. A natural marquise averages $7,453; the lab-grown equivalent averages $1,059. Radiants aren't far behind at 84.7%, and cushions sit at 83.9%.

Shape	Natural Avg	Lab-Grown Avg	Gap
Marquise	$7,453	$1,059	85.8%
Radiant	$7,326	$1,119	84.7%
Cushion	$7,184	$1,157	83.9%
Pear	$8,057	$1,335	83.4%
Round	$8,175	$1,996	75.6%
Princess	$4,319	$1,197	72.3%

Round brilliants, the most popular shape by far, show a 75.6% gap. The average natural round in our database sits at $8,175. The average lab-grown round: $1,996. Princess cuts have the narrowest gap at 72.3%, still enormous in dollar terms.

With natural prices sliding and lab-grown firming, both sides of this equation are pushing the gap wider. For budget-conscious buyers, these numbers continue to speak for themselves. You can browse current pricing across all shapes using our advanced search tools.

Same stone, very different receipt

Cross-retailer price spreads remain staggering this week. For lab-grown marquise diamonds, the average spread between the cheapest and most expensive retailer for comparable stones is 100.6%. You could pay double for the same lab-grown marquise simply by picking the wrong shop.

Natural ovals show an average cross-retailer spread of 85.2%. Lab-grown ovals: 83.9%. Lab-grown pears: 82.4%. These aren't minor discrepancies. Comparison shopping across retailers can save you more than almost any other single decision you'll make, including the choice between natural and lab-grown within the same quality tier.

Retailer markups tell the story even more plainly.

Retailer cohort (anonymised)	Active Listings	Avg vs cohort median
Smallest by inventory in cohort	~700	+111.4%
Large US-anchored A	~126k	+5.0%
AU-region mid-size	~92k	+0.6%
Large US-anchored B	~24k	Benchmark
Specialist value-cohort retailer	~1,400	minus 13.6%

The highest-markup retailer in the cohort averages 111.4% above the cohort median across ~700 listings. More than double the median market price. If you're shopping there without checking prices elsewhere, you're almost certainly overpaying. Significantly. At the value end of the cohort, one specialist retailer in our index runs about 13.6% below the cross-retailer median (small inventory, sharp pricing). An Australia-anchored mid-size retailer sits nearly flat at about 0.6% above median across ~92,000 listings, making it one of the most competitively priced large-volume sellers in the dataset. The largest US-anchored retailer falls in between at around 5.0%, reasonable given scale.

Our cross-retailer comparison tools exist precisely for these kinds of spreads. A few minutes comparing prices across retailers can save you hundreds, sometimes thousands.

Five stones that caught my eye

Our value detection system flagged several stones this week, all scoring a perfect 1.000 on our scale. These are priced dramatically below median for their category.

A natural pear, E colour, 0.51ct, listed at $187. That's 76% below the median per carat price of $1,553. An E colour pear under $200 is unusual by any measure. If you need a natural accent stone or a delicate pendant centrepiece, this category is worth browsing.

A natural emerald cut, L colour, 0.70ct, at $301 sits 65% below median. Warm colour, yes, but at $430 per carat against a median of $1,230, you're paying a fraction of the going rate. For a vintage style setting where warmth is the point, that's solid buying. On the lab-grown side, a radiant in H colour at 1.00ct for $1,016 is 65% below its category median of $2,910 per carat. A one carat lab-grown radiant with near colourless grading at that price is strong value.

Also spotted: a natural marquise, F colour, 0.42ct, at $272 (59% below median) and a natural round, M colour, 0.41ct, at $246 (52% below). Stones priced this far under market tend to disappear within days. You can browse all current exceptional value signals and set alerts for your preferred specs.

What I'm watching next week

Natural round supply is the big one. The 419% surge in 1.00 to 1.24ct rounds and 225% jump in 1.50 to 1.99ct rounds can't be ignored. If these stones don't find buyers quickly, expect further softening in the most traded natural category on the market. Round brilliants above a carat are the bellwether of natural diamond pricing, and right now they're flashing caution.

Lab-grown absorption capacity matters just as much. Supply flooded in this week, particularly in smaller rounds, and prices held or rose. That dynamic can't continue indefinitely unless demand keeps pace. A pullback in lab-grown prices would be the first meaningful one since early March, and it would change the calculus for buyers sitting on the fence.

Then there's the I clarity story. Nearly every major mover this week, rising or falling, landed in the I (included) clarity range. Natural included stones are getting hammered. Lab-grown included stones are finding a floor and, in some cases, rallying hard. Whether that divergence holds will tell us a great deal about how each market values lower grade inventory going forward.

For buyers, it comes down to this. If you want natural, patience is paying off. Prices are falling, supply is rising, and you're getting better selection at lower costs each passing week. There's no urgency to buy today what will likely be cheaper next Friday. If you want lab-grown, the window on current pricing may be tighter than it looks. Prices firmed this week and the strongest value stones are being bought up quickly. Whichever market you're in, compare across retailers before you commit. The single biggest waste of money in diamonds isn't buying the wrong stone. It's buying the right stone from the wrong shop.