Lucy's Diamond Insights
Deep market analysis, price trends, and diamond buying intelligence from Lucy, our resident diamond market analyst.
Subscribe via RSSRound diamonds, a flooded market, and the arbitrage most buyers miss
Natural round diamonds are seeing their biggest weekly supply surge in months, with new listings flooding in across every major carat tier. The cross-retailer spread has reached 57%, meaning buyers who compare across retailers have a genuine advantage. A headline 104% price spike in melee rounds is a data artefact, not a market signal.
Eye-Clean Diamonds, How to Find SI1 Stones That Look Like VS1
An eye-clean SI1 can cost 25 to 40 percent less than a VS1 with identical specs, yet look identical at arm's length. The question isn't whether to buy SI1; it's which SI1 stones actually pass the test. This guide walks the four factors that matter, the GIA plot workflow, and the shapes where this strategy works and where it doesn't.
Natural Radiant Cuts Are Priced Below Median Across the Board Right Now
Natural 0.90ct F radiant cuts are listing between $627 and $1,238 on the open market right now, for stones with identical specifications. Lab-grown rounds carry a 60.7% cross-retailer spread, meaning the retailer you choose can cost as much as a carat upgrade. Two markets are moving in opposite directions, and both have specific opportunities worth acting on this week.
Small rounds surged 60% while big cushions quietly collapsed
Natural diamonds dipped 0.88% this week while lab-grown gained 2.72%, the first time in a month both markets moved in opposite directions simultaneously. Small natural rounds jumped over 60% in certain categories while large cushion cuts fell nearly 40% and lab-grown rounds in the same size range dropped 50% over the past month. Cross-retailer spreads on natural rounds remain at 56%, meaning buyers who compare are consistently finding major savings on identical stones.
The radiant market is splitting in half
Natural radiant cut diamonds are moving in opposite directions this week. Stones under 0.5ct in the N+ colour tier climbed 41% in seven days while 2ct to 2.5ct H-I radiant cuts fell nearly 49%. The spread tells a precise story about which end of the market to target and which to avoid.
Diamond Fluorescence, When the Blue Glow Saves You Money
The Strong fluorescence discount on D to H colour diamonds runs up to 15 percent, but most of those stones look identical to their more expensive counterparts. Knowing which colour range benefits from fluorescence and which doesn't, and how to inspect a stone before you buy, separates buyers who capture that discount from buyers who simply avoid the grade. We walk through every GIA fluorescence level, the real price impact by colour band, and how to screen for the 1 to 5 percent of stones with genuine milkiness.
Where the market is leaving money on the table right now
Three natural radiant cuts at 2.02ct F colour are sitting 54 to 69 percent below the category median. Natural emerald cuts show a 63 percent average spread across retailers. If you're in the market for a diamond and haven't compared prices across multiple sources, you're almost certainly overpaying.
Natural diamonds fell 4% this week. Large ovals took most of the damage.
Natural diamonds averaged down 4.1% this week, with large ovals correcting 54% in seven days after an extended run. Lab-grown pears moved the other direction, rising 51.4%. Cross-retailer pricing gaps on natural emerald cuts reached 63%, and two specific stones are flagged as genuinely exceptional value.
Best Online Diamond Retailers in 2026, Ranked by Price Transparency
Most ranked lists of online diamond retailers are paid placement. We monitor more than 14 million diamonds across 110 plus retailers without taking affiliate revenue, and we rank by price competitiveness against the market median. The results aren't what the popular lists suggest.
Natural melee rounds jumped 49 percent in a week
Natural rounds in the 0.20 to 0.29 carat range, J to K colour, jumped 48.63% in seven days while the broader natural market fell 0.93%. With only 73 active listings, thin supply can amplify moves like this, but the simultaneous spike in L to M colour and D to E grade rounds suggests something more structural. Buyers sourcing melee diamonds need to know where the cross-retailer gaps sit before they commit.
Large naturals in freefall, fancy blues quietly underpriced
Large natural pear and oval diamonds dropped as much as 66.7% in seven days while lab-grown fancy blue stones sit 35% to 38% below category median. The cross-retailer spread on natural rounds is 57% and lab-grown emerald cuts carry a $228 average saving waiting to be claimed. The market is moving fast enough that where you shop and when you shop both matter.
Diamond Price by Carat, From 0.5ct Through 5ct With Live Bands
Natural diamond prices don't scale linearly with carat weight. At each major weight threshold, the price compounds sharply, and the step from below 0.75ct into the 1ct band alone represents a 4.25 times increase in median price. This post maps median prices, per carat rates, and weight premium steps for round brilliants across both natural and lab-grown markets.