Start with issuer, identity and scope
Confirm the laboratory, report number, issue date and the type of service provided. Check whether the material is identified as natural or laboratory-grown and whether the report concerns a loose stone or mounted jewellery. Use the issuer’s own verification service to compare the details. Report formats change over time, so an unfamiliar layout calls for verification rather than an immediate assumption that it is invalid.
Match the basic measurements
Compare shape, carat weight and dimensions with the listing and the offered stone. Carat measures mass: one carat equals 200 milligrams. Measurements help explain the stone’s visible size and suitability for a setting. A laser inscription, when present, can assist identification, but its presence is not a substitute for matching the full set of information. Ask for clarification when identifiers or specifications do not agree.
Read quality descriptions together
Colour, clarity, cut information, polish and symmetry describe different aspects of the stone. The relevant fields depend on the laboratory and report type. Where a clarity plot is included, it records particular characteristics rather than functioning as a photograph of everyday appearance. A report also cannot show every preference-sensitive aspect of a fancy shape. Use consistent images or video alongside the documented observations when assessing the final selection.
Check comments and current terminology
Look for origin, growth-method and treatment disclosures where the service reports them. Do not infer untreated status from silence in a shortened listing. For qualifying colourless-to-near-colourless laboratory-grown diamonds, GIA introduced Premium and Standard overall assessments in October 2025. IGI continues 4Cs laboratory-grown reporting. Read each issuer’s wording as issued; avoid translating different report systems into supposedly equivalent grades without an appropriate basis.
Know what a report does not establish
GIA describes its reports as technical assessments, not certificates or appraisals. A grading report does not by itself promise a resale price, document every supply-chain stage or certify environmental performance. If valuation, provenance or a sustainability claim matters, request the corresponding evidence separately. Before confirming a purchase, keep the verified report with the final written specification so future discussions refer to the same identified stone.