Diamond Certification
Use an independent grading report to verify the characteristics you are paying for.
Diamond Certification & Grading Reports
A grading report documents measured and observed characteristics. It is one of the most important buying documents—but it does not replace visual inspection, retailer due diligence or an independent appraisal when one is appropriate.
GIA Reports
What GIA reports contain, how to verify a report and how to use the data.
IGI Reports
How IGI grading fits into natural and laboratory-grown diamond shopping.
Read a Report
A field-by-field decoder for the measurements, grades, comments and plots.
Laboratory Comparison
How to compare reports without reducing the decision to a logo.
What a grading report can tell you
Depending on the report type, it can document carat weight, color, clarity, cut information, measurements, polish, symmetry, fluorescence, proportions, clarity characteristics, inscriptions and comments. Report formats differ by laboratory and service.
What it cannot tell you
A grading report is not a promise that you will love the diamond. It does not capture every visual nuance, market price, setting quality or retailer service issue. It is evidence for a buying decision—not the entire decision.
Verify the report
Use the issuing laboratory's official report-check service where available. Match the report number and core characteristics to the listing and, when possible, the laser inscription on the diamond.
Core gemology references: Gemological Institute of America (GIA) diamond education and research materials. Consumer terminology and disclosure principles: U.S. Federal Trade Commission Jewelry Guides. Last reviewed August 2026.