How to read an IGI report
Every grading line, explained
Every diamond we sell comes with a report from the International Gemological Institute (IGI), one of the world's largest independent grading labs. The report is the stone's ID card: an unbiased, third-party description of exactly what you're buying. Here's how to read each part.
The report number
At the top you'll find a unique report number. This is the single most useful thing on the page — you can type it into IGI's free verification tool at igi.org/verify-your-report and see the official grading straight from the source. If a seller's listing matches the lab's record, you know it's legitimate. We print this number on every listing for exactly that reason.
Carat weight
Carat is weight, not size — one carat equals 0.2 grams. Two diamonds of the same carat can look different sizes depending on how they're cut, which is why measurements (below) matter too. Prices rise sharply at round numbers like 1.00, 2.00, and 3.00 carats, so a 0.95ct stone can be a smart value.
Color
Graded D (completely colorless) down through Z (light yellow or brown). D–F is colorless, G–J is near-colorless and where most buyers find the best balance of beauty and price — at G or H, the average person won't see any color once the stone is set.
Clarity
This describes tiny natural inclusions, on a scale from FL (flawless) through IF, VVS1/VVS2, VS1/VS2, SI1/SI2, down to I1–I3. "Eye-clean" means no inclusions are visible without magnification — many VS and even SI1 stones are eye-clean, so you rarely need to pay for the very top grades to get a flawless-looking diamond.
Cut, polish & symmetry
Cut is graded Excellent down to Poor and is the biggest driver of sparkle — a well-cut stone bounces light back at your eye. Polish and symmetry describe the quality of the finishing. For maximum brilliance, look for Excellent or Very Good across all three. Note that "Cut" grade is given for round diamonds; fancy shapes are judged more on polish, symmetry, and proportions.
Measurements & proportions
The report lists the stone's dimensions in millimeters, plus the table %, depth %, and length-to-width ratio. The ratio tells you the outline: a round is about 1.00, while an elongated oval might be 1.40. Use these to picture how the diamond will actually look face-up.
The takeaway
You don't need to chase the top grade in every category. The sweet spot for most buyers is a well-cut, eye-clean, near-colorless stone — and the IGI report lets you confirm all of that independently. Browse our collection; every stone shows its IGI number so you can verify it before you buy.