How do I verify an IGI or GIA certificate number?

Quick answerUpdated November 1, 2026

Type the number in yourself on the laboratory’s own website: IGI’s verification at igi.org, or GIA’s Report Check at gia.edu, never a link or QR code from the seller. The online report must match the listing and the stone: shape, carat weight, measurements in millimetres, colour and clarity grades (or, for a GIA lab-grown assessment since 1 October 2025, “Premium” or “Standard”), and “laboratory-grown” if the stone is lab-grown. Then have a jeweller read the number laser-inscribed on the girdle, because a genuine report number can be copied onto a different stone.

Illustration: how do i verify an igi or gia certificate number? — Illustration (AI render): the girdle, the thin outer edge of a diamond where report numbers are laser-inscribed.

1. Find the number on the report and on the stone

An IGI report prints its number at the top. On the IGI lab-grown sample report listed under Sources, the number begins with LG and is repeated under “Inscription(s)”, meaning it is laser-inscribed on the girdle. Since 1 October 2025, GIA laser-inscribes every lab-grown diamond it assesses with “Laboratory-Grown” and its GIA quality assessment number. On a natural diamond with a GIA Diamond Grading Report, the inscription is an optional extra at an additional charge, so a natural stone may have none.

2. Look it up on the laboratory’s own website

Type the address and the number yourself: igi.org for IGI, and Report Check on gia.edu for GIA. Do not follow a link or scan a QR code supplied by the seller: in 2018 the Thai laboratory AIGS warned that fake reports bearing its logo had working QR codes that opened a look-alike website. If a GIA lab-grown assessment number does not come up online, ask GIA before you rely on it.

3. Match the report to the listing

Shape and cutting style, carat weight, measurements, colour and clarity grades, and the description must all match the listing. An IGI report gives letter grades, such as E colour and VVS 2 clarity. Since 1 October 2025 GIA describes colourless lab-grown diamonds only as “Premium” (D colour, VVS clarity or better, Excellent polish and symmetry, and an Excellent cut grade on round brilliants) or “Standard” (a stone that misses Premium but still reaches at least J colour, VS clarity, Very Good polish and symmetry, with Good symmetry allowed on fancy shapes, and a Very Good cut grade on round brilliants); a stone below Standard gets no GIA assessment. The description must say laboratory-grown if the listing does. The measurements are the best cross-check: two stones can share a weight and a grade, but measurements given to a hundredth of a millimetre are far less likely to coincide.

4. Tie the report to the stone

The report proves that a stone was graded; the inscription and the measurements show that this is that stone. Ask a jeweller or appraiser to read the girdle inscription under magnification, and to measure and weigh the stone. For a GIA report, GIA also offers a paid report verification service that confirms the report matches your stone; the original report has to go in with it.

Signs of a fake or mismatched report

Any one of these is a reason to return the item: the number is not found on the laboratory’s own website; the online record differs from the paper or the listing in shape, weight, measurements or grades; the report says laboratory-grown but the listing says natural, or the other way round; the link or QR code opens a site that is not igi.org or gia.edu; a GIA report dated after 30 September 2025 gives a colourless lab-grown diamond D-to-Z colour and clarity grades, which GIA no longer issues; or the girdle inscription is missing or different on a stone whose report lists one. A genuine number is not proof on its own: in January 2024 JCK reported that IGI found a 6.01 carat lab-grown diamond carrying a fake GIA inscription, copied from the real report of a natural diamond of the same weight, and given away only by a different inclusion and a different depth.

Frequently Asked Questions

Is a GRA certificate the same as an IGI or GIA report?

No. The GRA cards that come with most moissanite are seller-facing certificates, not reports from an independent laboratory. See is a GRA certificate real?

Can a report be faked?

Yes. A printed report can be copied, fake reports have carried QR codes that open look-alike websites, and genuine report numbers have been laser-inscribed on the wrong stones. That is why you type the number into the laboratory’s own website yourself and match the measurements and inscription to the stone, rather than trusting the paper in the box.

Does GIA still grade lab-grown diamonds from D to Z?

Not since 1 October 2025. GIA’s Laboratory-Grown Diamond Quality Assessment calls a stone Premium or Standard, inscribes “Laboratory-Grown” and the assessment number on the girdle, and gives no assessment to stones below Standard. GIA reports issued before the change remain valid. For letter grades on a lab-grown stone, look for an IGI report.

What should I do if the report does not match?

Use the return window on the listing. For items from third-party sellers, Amazon’s A-to-z Guarantee also covers an item that is damaged, defective or materially different from what you ordered, once you have asked the seller for a return. Keep screenshots of the online report and any appraisal as evidence.

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