Four steps to check a stone
Find the number
Find the report number on the paper or PDF, and on the stone's girdle (laser inscription, seen under 10x magnification).
Check with the lab
Enter it on the lab's own page, below.
Compare
Check shape, carat weight and grades match the stone's listing.
Match the girdle
Check the girdle inscription matches the report number. If anything doesn't match, stop and call us.
An online lookup confirms the report is genuine in the lab's records. It does not prove the stone in your hand is the one in the report. Only the girdle inscription does.
Check with the lab
GIA
Gemological Institute of America. Enter the report number to see the report.
GIA Report Check ↗IGI
International Gemological Institute. Enter the report number to see the report.
IGI Verify your report ↗HRD
HRD Antwerp. Look up the certificate number on HRD's portal.
HRD Antwerp ↗
Reading a report
Match the report number, shape and carat weight to the stone. Natural diamond reports also record measurements, colour, clarity, cut (for round stones), polish, symmetry and fluorescence.
Laboratory-grown stones: GIA reports issued from 1 October 2025 give a Premium or Standard assessment instead of colour and clarity grades, and earlier GIA reports stay valid. GIA lab-grown girdles read Laboratory-Grown plus the report number; IGI lab-grown inscriptions start with LG, so include the prefix.
Stones without a report
Melee and cut-to-spec stones are graded in-house and sold without a lab report. They're labelled that way in our listings.