Education
How to Check That a Grading Report Is Real β and Is for Your Stone
Two different questions, and the second one catches more problems than the first.
Written by the Mapple Gems workshop, Surat Β· Updated 7 September 2026
Short answer
Verifying the report takes one minute: look the number up on the laboratoryβs own site and check every figure against the PDF you were sent. Verifying that the report belongs to your stone is the harder part β do it by matching the girdle inscription to the report number, and by checking the measurements against the physical stone. A report describes a stone, not a ring, and the inscription is the only thing tying one to the other.
Most people treat a grading report as the end of the verification process. It is better thought of as the beginning: the document is easy to check, and the link between the document and the object in front of you is the part that actually needs attention.
Step one: verify the report itself
- Go to the laboratoryβs own website directly. Type the address yourself rather than following a link from the seller β IGI, GCAL and GIA all publish report lookup tools.
- Enter the report number. It is printed on the report and, for most certified stones, laser-inscribed on the girdle.
- Compare every field against the copy you were sent β carat weight, measurements in millimetres, colour, clarity, cut, polish, symmetry, and whether it is stated as laboratory grown.
- Treat any mismatch as decisive. A PDF can be edited; the laboratoryβs database cannot.
If the number does not resolve at all, that is a conversation to have before paying, not after.
Step two, which almost nobody does: check the report is for the stone you are holding. Reports are issued to loose stones, before setting. So a genuine, verifiable report proves that a stone with those characteristics exists β not that it is the one in your ring. The link between them is the girdle inscription: a laser marking of the report number on the stoneβs outer edge, readable under 10Γ magnification. Ask the seller to confirm the stone is inscribed, and have a jeweller read it against the report at handover or at your first service. This is not an accusation; it is simply the only step that connects the paperwork to the object, and it is the one routinely skipped.
What the measurements tell you
A second, easier cross-check that needs no magnification.
Every report states the stoneβs dimensions in millimetres β diameter for a round, length and width for a fancy shape, and depth. Those can be checked against the physical stone with callipers, or approximately against the setting.
If a report describes a 6.5Β mm round and the stone in the ring measures 6.1Β mm, something is wrong regardless of how genuine the document is. Measurements are the cheapest verification available and they need no equipment beyond a ruler for a rough check.
Which laboratories, and what each means now
| Laboratory | For lab grown stones |
|---|---|
| IGI | Full 4C detail including cut, polish and symmetry. The most common report on lab grown. |
| GCAL | Full detail, with additional optical performance analysis. |
| GIA | Moved to a Premium or Standard assessment for lab grown from October 2025 β less granular than before. |
| Sellerβs own card | Not a grading report. No independent assessment behind it. |
That last row is worth dwelling on. An attractively printed card with the shopβs name on it is a description, not a certification, and βcertifiedβ without a named laboratory means nothing checkable.
What has no report, legitimately
Several things, and their absence is not a warning sign.
- Melee β accent stones under roughly 0.2Β ct are never individually graded in any material, because the fee would exceed the stoneβs value. They are sold by parcel specification.
- Moissanite β no major laboratory grades it on the diamond colour or cut scales, so seller colour claims are assessments rather than certifications and are not comparable between sellers.
- Small lab grown stones below about 0.30Β ct, where individual reports become uncommon.
What matters is that a seller states clearly which category a stone falls into rather than implying certification that does not exist.
Keeping it useful afterwards
The report matters most years later, so store it accordingly.
Keep a digital copy somewhere other than your house, along with photographs of the piece and the full written specification. An insurer generally wants a valuation with a detailed specification rather than a grading report β but the report is what makes producing that specification straightforward, and it is what lets a jeweller match a replacement stone if one is ever lost.
Keep reading
Frequently asked questions
How do I check a diamond grading report is genuine?
Go to the laboratoryβs own website directly β typing the address yourself rather than following a sellerβs link β enter the report number in their lookup tool, and compare every field against the copy you were sent. A PDF can be edited; the laboratoryβs database cannot. Treat any mismatch as decisive.
How do I know the report is for the stone in my ring?
By the girdle inscription β a laser marking of the report number on the stoneβs outer edge, readable under 10Γ magnification. Reports are issued to loose stones before setting, so a genuine report proves such a stone exists, not that it is yours. Also check the reportβs millimetre measurements against the physical stone.
Is a sellerβs own certificate worth anything?
It is a description rather than a certification β there is no independent assessment behind it and nothing to look up. βCertifiedβ without a named laboratory and a verifiable report number means nothing checkable. IGI and GCAL give full 4C detail on lab grown; GIA moved to a Premium or Standard assessment from October 2025.
Should every stone in a ring have a report?
No. Melee under roughly 0.2Β ct is never individually graded in any material, moissanite is not graded on the diamond scales by any major laboratory, and lab grown stones below about 0.30Β ct rarely carry individual reports. What matters is that a seller states plainly which category a stone falls into rather than implying certification that does not exist.
Ask whether the stone is inscribed.
It is the only thing connecting a report to the object, and it takes a jeweller ten seconds to read.
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