Introduction
A grading report is only as trustworthy as its connection to the diamond it describes. Forged reports exist. So do altered reports — documents where a grade has been changed, a carat weight adjusted, or a report number borrowed from a different stone. The most efficient safeguard available to any buyer is also the simplest: verify the report online through the issuing laboratory's database.
GIA, HRD Antwerp, and IGI — the three laboratories most commonly encountered on the Czech and European market — each maintain a free online verification system. These tools return the diamond's graded characteristics as recorded in the laboratory's files. If the information on screen matches the printed report and the stone in front of you, the report is genuine. If it does not, you have a problem worth investigating before any money changes hands.
This article walks through each laboratory's verification process: what you need to enter, what the system returns, and what to compare. For context on what grading reports contain and how to read them, see What a Report Contains. For how to match the report number to the physical inscription on the diamond, see Report Number & Inscription.
GIA Report Check
GIA's verification tool is called Report Check and is accessible through the GIA website.
What you need
- The report number — a numeric string printed in the report header (e.g., 2215432567). On diamonds with girdle inscription, this same number is laser-engraved on the stone.
What the system returns
After entering the report number, GIA displays the diamond's key graded characteristics as recorded in their database:
- Report type — Diamond Grading Report or Diamond Dossier
- Date of issue
- Shape and cutting style (e.g., Round Brilliant)
- Measurements in millimetres
- Carat weight
- Colour grade
- Clarity grade
- Cut grade (for round brilliants)
- Polish and symmetry grades
- Fluorescence
For full Diamond Grading Reports, the result may also include the proportions diagram and clarity plot. For Diamond Dossiers, the display is more compact but covers the essential grades.
What to compare
Match every field on the screen against the printed report. Pay particular attention to:
- Carat weight — even a small discrepancy (e.g., 1.01 vs. 1.10) indicates a mismatch
- Clarity and colour grades — one grade off suggests the report may have been altered or belongs to a different stone
- Measurements — the three dimensions (minimum diameter × maximum diameter × depth for rounds) should match exactly
- Date of issue — confirms you are looking at the correct version of the report, not an older or superseded one
If GIA's system does not recognise the report number, the document may be counterfeit. If the number is found but the grades differ from the printed report, the document has been altered.
HRD Antwerp — My Diamond
HRD Antwerp provides online verification through its My Diamond portal.
What you need
- The report number from the HRD grading report
Some queries may also require a secondary verification field, such as the carat weight or a security code printed on the report. Check the report itself for any supplementary verification details HRD has included.
What the system returns
The HRD portal displays the graded characteristics as recorded in their database:
- Report type and number
- Shape
- Weight
- Colour and clarity grades
- Cut, polish, and symmetry assessments
- Measurements and proportions
- Fluorescence
HRD reports issued for the European market often include additional detail on proportions, reflecting the laboratory's emphasis on cut analysis.
What to compare
Follow the same logic as with GIA: match every field against the physical report. HRD serves a significant share of the Antwerp trade, and their reports are common in Czech jewellery shops that source from Belgian dealers. If the printed report claims HRD origin but the verification system does not recognise the number, treat this as a serious red flag.
IGI Verify
IGI offers report verification through its website.
What you need
- The report number
- In some cases, the total carat weight as an additional verification step
What the system returns
- Report type (Natural Diamond Report, Laboratory-Grown Diamond Report, or Jewellery Report)
- Shape and cut
- Weight
- Colour, clarity, and cut grades
- Polish and symmetry
- Measurements
- Fluorescence
IGI grades both natural and laboratory-grown diamonds. The verification result will clearly indicate which category the stone falls into. This is particularly important because laboratory-grown diamonds are visually identical to natural diamonds, and a report that has been altered to omit the "laboratory-grown" designation would be a form of misrepresentation.
What to compare
All fields, as with GIA and HRD — but pay special attention to the natural vs. laboratory-grown designation. If you are buying a stone sold as natural, the IGI verification result must confirm it as natural. Any discrepancy here is not a minor clerical issue; it is a fundamental misrepresentation of the product. See Natural vs Lab-Grown Overview for more on the differences between these categories.
When Verification Fails
Not every failed lookup means fraud. There are legitimate reasons a report number might not appear:
- Very recent reports may not yet be indexed in the online system. Most laboratories update their databases within days, but brief delays occur.
- Older reports issued before a laboratory launched its online database may not be available digitally. GIA's online database covers reports from approximately 1 January 1999 onward.
- Regional report types from certain IGI offices may use verification portals specific to that region.
However, the following situations warrant immediate caution:
The report number is not found
If the number does not exist in the laboratory's system and the report is not extremely old, the document may be fabricated. Do not proceed with the purchase.
The grades do not match
If the online record shows different grades from the printed report — even by one grade in colour or clarity — the document has been altered. A VS2 on paper that returns as SI1 online means someone changed the report after it was issued.
The report is flagged
Some laboratories flag report numbers that have been reported as lost, stolen, or associated with suspicious activity. If the system returns a warning rather than standard results, contact the laboratory directly.
What to do
- Do not complete the purchase. Politely decline and explain that you need to resolve a documentation discrepancy.
- Contact the laboratory. GIA, HRD, and IGI all have client services departments that can investigate. Provide the report number and describe the discrepancy.
- Consider independent examination. If the stone matters to you and the seller has a plausible explanation (e.g., a re-cut that changed the weight), have the diamond submitted for fresh grading. This costs money and time but provides certainty.
- Know your rights. Under EU consumer protection regulations — which apply in the Czech Republic — sellers must provide accurate information about the products they sell. A diamond sold with a falsified or mismatched grading report violates these obligations. Czech Trade Inspection (Česká obchodní inspekce) handles complaints related to misleading product information.
Practical Advice
- Verify before you pay, not after. Once money has changed hands, resolving a documentation problem becomes significantly harder.
- Verify in front of the seller. A reputable jeweller will have no objection to you checking the report number on your phone while in the shop. If a seller discourages verification, consider why.
- Cross-check the inscription. Online verification confirms the report is genuine. Girdle inscription confirms the report belongs to that specific stone. Use both. See Report Number & Inscription.
- Screenshot the result. Save a screenshot of the online verification page at the time of purchase. This creates a timestamped record of the grades the laboratory had on file when you bought the diamond.
- Use the laboratory's own website. Third-party lookup sites may display outdated or inaccurate data. Always verify through the issuing laboratory directly.
Summary
Every major gemological laboratory maintains a free online database where you can verify a diamond grading report by entering its report number. GIA's Report Check, HRD Antwerp's My Diamond portal, and IGI's verification tool each return the diamond's graded characteristics as the laboratory recorded them. Matching these results against the printed report and the physical stone confirms three things: the report is genuine, it has not been altered, and it belongs to the diamond in question. Always verify before purchase, not after. If verification fails — the number is not found, the grades differ, or the system flags an issue — do not proceed until the discrepancy is resolved. This takes less than a minute and is the single most effective step a buyer can take to protect against misrepresented diamonds. For how different laboratories compare in grading standards, see Why Grading Differs Between Labs. For a broader introduction to grading reports, see Reports 101.