Lucy's Diamond Insights
Deep market analysis, price trends, and diamond buying intelligence from Lucy, our resident diamond market analyst.
Subscribe via RSSBest 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 Current 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.
The natural diamond market split in two this week
Natural diamonds averaged down 2.66% this week while lab-grown edged up 1.70%, but those averages bury the real story. A 67% crash in 4ct to 5ct natural hearts, a 61% surge in D to E rounds, and a 49% collapse in lab-grown entry level rounds all happened in the same seven days. The market is moving in sharply different directions depending on which category you're watching.
Lab-Grown Diamond Price Chart 2020 to 2026, the 80 Percent Collapse
Lab-grown diamond prices have fallen roughly 80 percent since 2020, with the median for a 1ct G VS2 round brilliant dropping from around $3,400 to between $700 and $900 per carat. This is not a story about consumer rejection. CVD reactor capacity from India and China outpaced demand, and the year-by-year price data shows exactly when and how fast.
Diamond Carat Weight Guide, Magic Sizes and the Shy Carat Trick
A one carat diamond is a weight, not a size. Two stones with identical certificates can look dramatically different face up. Understanding magic size pricing and the shy carat trick can save you 8 to 15 percent on a stone that faces up indistinguishably from its heavier, pricier neighbour.
Diamond Colour Guide, D Through Z With Settings That Hide Warmth
The GIA colour scale runs from D to Z but what matters in wear is how your chosen grade reads against your setting metal. An H in yellow gold faces up white; an H in platinum shows warmth. This guide walks every colour band and tells you where the real value sits.
Diamond Clarity Guide, FL Through I3 With Real Inventory Data
The GIA clarity scale runs eleven grades from FL to I3, and most buyers shopping round brilliants under 1.5 carats can ignore eight of them. VS2 is the sweet spot for rounds, VS1 is the minimum for step cuts, and the real work for SI1 stones is in the inclusion plot, not the grade.
How Much Does a 1 Carat Diamond Cost in 2026, Current Data
The median price for a 1ct natural round brilliant sits at $2,730 USD in August 2026, based on over 272,000 active listings across 110 retailers. Lab-grown rounds at the same weight class have a median of $362, an 87 percent discount that widens as carat weight increases. Colour, clarity, shape, and the threshold effect at exactly 1.00ct all move the number significantly from that median.
How to Read a GIA Diamond Report, Field by Field
A GIA grading report has far more information than the headline colour and clarity grades. This field-by-field walkthrough covers every section from the header and proportions diagram through to the comments field, where the details that actually affect price are hiding.
Diamond Cut Guide, Why Cut Matters More Than the Other 3Cs
Cut is the only C that changes how a diamond performs after it leaves the ground. Two stones with identical colour, clarity, and carat weight can look completely different because of cut, and that difference is visible to the naked eye in any normal light. This guide covers the GIA five-grade scale, the proportions that drive each grade, and what to do when a cut grade doesn't exist.