Diamond Grading Labs: Compare the Report, Not Just the Logo
A laboratory report is a structured description of a diamond. Different laboratories and report services can use different formats, so compare the actual data, verify the report and inspect the stone.
GIA
Understand GIA report fields and verification.
IGI
Understand IGI report fields and lab-grown context.
Use the report for four jobs
- Identify the stone.
- Document the 4Cs and measurements.
- Expose proportions, finish, fluorescence and comments.
- Create a common basis for comparison.
Do not treat “certified” as a beauty guarantee
Grading reports do not promise that a diamond will be attractive to your eye, fairly priced or suitable for a particular setting. They also are not the same as an appraisal, which addresses value for a stated purpose.
Verification matters
Use the issuing laboratory's report-check system where available. Match the report number and key fields to the retailer listing and any laser inscription.
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.