Diamonds
The 4Cs that actually move price, cut and proportions, lab-grown vs natural economics, and what to pay.
Edited by CaratWire Editorial Desk · Senior gemological editor (G.G. (GIA), FGA on desk)
Live reference: the 2026 diamond price-per-carat index — round and fancy-shape ranges by carat weight and GIA/IGI grade, refreshed on a rolling basis.
Antique European Cut Diamond: History, Identification & 2026 Market Values
An antique European cut diamond can trade anywhere from $2,500 to $20,000+ per carat in 2026. Here's how to identify a genuine period stone, read its angles, and price it against the current collector market.
2026 Lab-Grown Diamond Price Per Carat: $200–$1,800 IGI/GIA by Clarity
2026 lab-grown diamond price per carat by clarity — $200 (SI2) to $1,800+ (FL) on IGI and GIA-graded comps, by clarity grade FL to SI2 and size band. When to spend up on clarity, when to take the eye-clean SI1.
Lab-Grown Diamond Resale Value in 2026: The Per-Carat Reality Check
Lab-grown diamond resale values in 2026 are sitting at 5–20% of original retail across most exit routes. Here's the per-carat math by size, by lab report, and what to do if you bought one in 2021.
CVD vs HPHT Lab-Grown Diamonds: How the Two Methods Differ at the Counter
CVD and HPHT lab-grown diamonds are both real diamond, but they grow differently and carry different telltales under a loupe. Here's how to spot them and which to buy in 2026.
IGI vs GIA Lab-Grown Grading: What the 2025 Report Format Change Means
IGI still prints the 4Cs on lab-grown diamond reports. GIA dropped to a Premium/Standard tier in October 2025. Here's which report to ask for, and how to price the difference.
Diamond Shapes Compared: Price, Sparkle, and Which Ones Hide Flaws
Six diamond shapes compared on price-per-carat, sparkle, finger-coverage, and which hide vs expose inclusions and color tint — with real ranges and counter scripts.
Diamond 4Cs Ranked by What Actually Moves Price and Looks
A skeptical, numerate breakdown of the diamond 4Cs — ranked by price impact and visible beauty. Where buyers overspend on clarity and color, and underspend on cut.
Diamond Fluorescence: When Blue Costs You and When It Pays You Back
Diamond fluorescence is a 10-15% discount the trade prices like a defect. Here is the GIA grading data, the per-carat math, and when blue actually pays you back.
Diamond Cut Grade: The Only C That Makes a Diamond Sparkle
The diamond cut grade is the one C that color and clarity can't buy back. How to read proportions, verify with ASET, and put your premium where it actually shows.
Moissanite vs Diamond: An Honest, Numerate Buyer's Guide to Fire, Hardness, and Price
Moissanite vs diamond, by the numbers: 2.4x the fire, 9.25 vs 10 hardness, honest price ranges per carat, the loupe test, and why neither is an investment.
2026 Diamond Price Per Carat: $5,500/ct (1 ct) to $18,000/ct (2 ct) — GIA Guide
$5,500–$9,500/ct for a 1 ct GIA-graded natural diamond in 2026, $11,000–$18,000/ct for a 2 ct, and $450–$900/ct for a 1 ct IGI lab-grown. Where the 1, 1.5, and 2 ct threshold jumps land — and what to pay.
Old European Cut Diamond: How to Value and Certify Antique Cuts
An old european cut diamond can trade at a discount or a premium. Learn how chunky facets, small tables, and open culets affect value, light, and price.
Fancy Color Diamonds: What Actually Drives Price (and Where Lab-Grown Wrecks Resale)
Fancy color diamonds are priced by hue, saturation, and rarity — not carat. Here's the real per-carat math, plus where lab-grown destroys value and the yellow exception.
Diamond Carat and Size: Why a Well-Cut 0.90ct Can Face Up Bigger Than a 1.00ct
Diamond carat and size aren't the same thing. Learn how cut depth and spread set the face-up mm a buyer actually sees — plus target diameters by shape and per-carat math.
Eye Clean Diamond: How to Buy SI1 and SI2 That Looks Flawless for Less
An eye clean diamond in SI1 or SI2 can look flawless to the naked eye while costing far less than VS or VVS. Here's how to buy by inclusion location and verify it.
Clarity Enhanced Diamond: How to Spot Treated Stones Before You Overpay
A clarity enhanced diamond can look two grades better than it is. Bench-level tells, which treatments GIA won't grade, and a counter checklist to avoid overpaying.
GIA vs IGI: Which Diamond Lab to Trust (and How to Adjust Your Offer)
GIA vs IGI compared on natural and lab-grown diamonds: where IGI grades softer, why GIA dropped the 4Cs on lab-grown, and the per-carat math to adjust your offer.
Lab-Grown vs Natural Diamonds 2026: 1ct D-VS1 — $1,400 vs $8,200
GIA-graded 1ct D-VS1 naturals run $7,800–$9,400; identical IGI lab-grown stones now sell for $1,200–$1,600. Resale, certification, what to actually buy.
Do Diamonds Hold Value? The Honest Resale Math Most Jewelers Won't Show You
Do diamonds hold value? Honest resale math: natural stones recover ~20-40% of retail, lab-grown near zero. What actually holds value, and how to buy smarter.
Lab Grown Diamond Resale: Why the Secondary Market Barely Exists
Lab grown diamond resale recovers cents on the dollar. Here's the price-collapse feedback loop, real per-carat math, and when buying lab-grown still makes sense.