How to verify a diamond grading report and supplier paperwork
Updated
A grading report tells you what a lab said about one stone. It does not tell you the stone in your hand is that stone, or that the seller is who they say they are. This guide covers both checks, in order.
Part 1: Check the report on the lab's own site
Never rely on a PDF or photo the seller sends. Take the report number and type it into the lab's official lookup yourself. Then compare every field (shape, carat weight, measurements, color, clarity, cut where graded) with the seller's paperwork and your own inspection.
| Lab | Official lookup | Notes |
|---|---|---|
| GIA | Report Check | Enter the report details on GIA's Report Check page. |
| AGS Laboratories | Verify a Diamond Grading Report | The American Gem Society has closed AGS Laboratories, but as of October 2026 its lookup is still online. Enter the AGS number as printed on the report (program report numbers and partner IDs are also accepted). Reports from 1 Jan 2001 to 1 Apr 2010 show grading details only; after 1 Apr 2010 you can also download the PDF. |
For any other lab, check its own website for a report lookup. If a lab does not offer an online lookup, ask it directly to confirm the report, using contact details from its own website, not from the seller.
What a lookup does and does not tell you
- It tells you the report number exists and what the lab recorded. If any field differs from the paper you were given, stop and ask why.
- It does not tell you the stone in front of you is the one described. A real report can be attached to a different stone.
Match the stone to the report
- Laser inscription. Many graded stones have the report number inscribed on the girdle. Look at it under a loupe or microscope and compare it with the report.
- Weigh and measure the stone and compare with the report.
- Re-test if value is high. For a large purchase, a gemological lab can confirm identity and whether a stone is natural or lab-grown. A seller who refuses this is a warning sign.
- Check the date and any "re-graded" notes on the report.
Part 2: Provenance and paperwork checklist before you pay a supplier
Tick each before you send money.
The supplier
- Legal name, address and business registration match across the invoice, the contract and the account you will pay.
- Bank or payment details came from a call or channel you started, not only from the email that carried the invoice. Confirm any change of details by phone.
- You can name who owns the business and how long they have traded.
The invoice or memo
- Describes each stone: shape, carat weight, color, clarity, report number.
- Carries a System of Warranties statement. The World Diamond Council describes the System of Warranties as a self-regulation framework: buyers and sellers of rough diamonds, polished diamonds and diamond jewelry add a warranty statement to their business-to-business invoices and memos. See the World Diamond Council.
Kimberley Process
- For rough diamonds, ask for the Kimberley Process certificate and the shipment details. For polished stones and jewelry, the System of Warranties statement is the usual paper.
The report
- Report number looked up on the lab's own site (Part 1) and every field matches.
- Laser inscription matches the report.
- Natural versus lab-grown is stated on the report and on the invoice.
Shipping and insurance
- Shipping route, carrier and insurance are written down, including who carries the risk until delivery.
- Return or inspection window agreed in writing before payment.
Payment
- Pay by a method that leaves a record tied to the invoice. Keep the invoice, report printout and lookup screenshot together.
If anything above is missing, ask for it before paying. A legitimate supplier can usually produce these quickly.
Next step
Once the paperwork checks out, Shield can pay your suppliers, including suppliers in China and Hong Kong, and you can put inventory spend on the Shield business credit card for luxury goods.