Source and scope
What GIA found. What I would check.
Source and scope: This is a GIA Gems & Gemology investigation, not a Your Diamond Guys client case. GIA did the testing. I explain what I would check before a buyer trusts that number. The article reports no buyer refund, retail purchase, or YDG recommendation.
- Stone submitted
- 3.07 carat round brilliant
- Laboratory
- GIA Antwerp
- Publication
- Summer 2021
What GIA found
The stone did not belong to the natural report.
GIA's Antwerp laboratory received a 3.07 carat round brilliant for an update service. The inscription referenced a previously graded natural diamond. The submitted stone was close to the natural report in weight and measurements, but GIA's testing identified CVD laboratory growth and post growth HPHT treatment. GIA added a laboratory grown inscription and made the counterfeit number illegible under its procedures.
| Characteristic | Natural diamond record, 2018 | Submitted lab diamond, 2021 |
|---|---|---|
| Weight | 3.078 carats | 3.075 carats |
| Shape | Round brilliant | Round brilliant |
| Measurements | 9.33 to 9.38 × 5.74 mm | 9.39 to 9.41 × 5.76 mm |
| Girdle | Slightly thick | Medium |
| Cut | Excellent | Excellent |
| Symmetry | Excellent | Excellent |
| Polish | Excellent | Excellent |
| Color | G | H |
| Long wave UV fluorescence | None | None |
| Clarity | IF | VVS2 |
| Inclusions | Not listed | Pinpoints, needles |
| Diamond type | Ia | IIa |
Read GIA’s original comparison. The precise weights and measurements above come from that investigation.
The close paper match is the uncomfortable part. Stop at the number and the paperwork looks convincing. GIA had to test the actual stone to find out how it grew.
A report and a physical stone
Make each check answer the right question.
| Step | What to match | What it can answer |
|---|---|---|
| GIA Report Check | Report type, number, shape, weight, measurements, grades, comments. | Whether the record exists and what GIA reported. |
| Actual stone inspection | Inscription, measurements, identifying clarity features where available. | Whether that report fits the diamond in front of you. |
| Qualified laboratory testing | Growth and treatment evidence when origin is in doubt. | Whether the stone is natural or laboratory grown and whether treatment needs disclosure. |
The report lookup is the beginning. It is not a remote origin test. If a listing claims natural origin, start with its full GIA natural report and confirm that the actual stone fits it. Our natural diamond verification guide walks through that order.
GIA corrected the identification on this stone.
In this same 2021 case, GIA added LABORATORY GROWN to the girdle on the left and made the counterfeit number illegible on the right. Those changes followed laboratory identification. An inscription alone had not established natural origin.
Keep the finding in context
One investigation does not measure the whole market.
One case cannot tell us how common this is or accuse a retailer you are considering. The useful lesson is simple. Check the stone as well as the number. If they do not match, stop and let a qualified lab settle it.
Your purchase
What I would ask before buying.
Start with the exact claim you are trying to verify. Natural origin needs a different answer from whether a report number exists.
- Save the full report and the seller’s stock number.
- Match current weight, measurements, and identifying features.
- Arrange a check by a qualified gemologist or lab while you can still return the stone.
GIA testing checks more than the number.
GIA’s black line is Type I. Red is Type II. The boxed region shows the nitrogen difference. A Type II result needs more testing because both natural and lab grown diamonds can fall in that group. These are GIA’s 2024 teaching spectra, not this case’s test results. Ask for the lab’s identification, not a guess from the chart.
The infrared teaching graph plots absorbance against wavenumber in reciprocal centimeters. The black Type I curve has nitrogen absorption in the boxed region around 1400 to 1000 reciprocal centimeters, while the red Type II curve lacks that feature. Type II includes natural as well as laboratory grown diamonds and requires further testing. These are separate 2024 teaching spectra, not the measurements collected in the 2021 copied inscription investigation.
Buyer questions
Your questions, answered
Is a laser inscription enough to verify a natural diamond?
No. This case shows why. Match the whole report to the whole stone and use physical testing if origin is uncertain.
Can a video prove natural origin?
No. I use video to judge how the stone looks. A qualified lab has to test it when natural origin is in doubt.
Should I avoid every diamond with an inscription?
No. An inscription is useful. Just do not treat it as the entire proof.