How to verify the authenticity of a lab-grown diamond
You've just bought a lab-grown diamond, or you're considering it – and you're wondering how to ensure that what you receive is indeed what was promised. It's a legitimate question, and the answer is simpler than you might think.
The IGI certificate: your primary guarantee
Every reputable lab-grown diamond comes with a certificate from an independent gemological laboratory. At Diamelys, each diamond is IGI certified – by the International Gemological Institute, one of the world's leading authorities for lab-grown diamonds.
This certificate is not a sales document. It is a scientific report prepared by independent gemologists, who represent neither the manufacturer nor the seller. It accurately specifies the carat weight, color, clarity, cut quality, and confirms the lab-grown origin of the stone.
If a seller cannot provide you with an IGI or GIA certificate for a diamond over 0.3 carats, it is a red flag.
Online verification of the report number
Each IGI certificate bears a unique report number. This number allows you to verify the certificate directly on the official IGI website, at igi.org, in the report verification section.
In a few seconds, you can access an official digital copy of the certificate – with all the characteristics of your stone. If the number does not return any results, or if the displayed characteristics do not match those of the paper certificate received, do not proceed.
Laser inscription on the stone
This detail is less known, but it is crucial. On every IGI certified diamond, the report number is laser-inscribed on the girdle – the edge of the stone, between the crown and the pavilion.
This inscription is microscopic, invisible to the naked eye. It is only readable with a ×10 magnification loupe. It creates a direct and permanent physical link between the stone and its certificate: impossible to falsify, impossible to swap.
At Diamelys, all our diamonds bear this laser inscription. If you have a loupe or if you visit a jeweler to have your piece checked, you can verify that the engraved number matches that on your certificate.
What the certificate does not cover – and how to complete it
The IGI certificate attests to the characteristics of the isolated stone. It does not certify the setting, the gold, or the quality of the assembly.
To ensure the overall quality of the jewelry, here are a few simple things to check upon receipt:
The hallmark on the setting – in France, 18K gold must bear a hallmark (an eagle for French pieces, or an import hallmark). This marking guarantees the gold content.
The solidity of the setting – the stone must be firm, without play. Slight movement to the touch indicates an insufficient setting.
The general finish – welds, prongs, and the interior surfaces of the ring must be clean and regular. A sloppy finish is quickly noticeable.
The Diamelys approach
At Diamelys, transparency is not a sales pitch – it's our fundamental way of operating.
Each diamond we offer is rigorously selected: only stones that meet our criteria of D-E color, minimum VS1 clarity are chosen. Each is IGI certified, with a verifiable report number and laser inscription.
Your certificate is provided with your jewelry.
Frequently Asked Questions
How to verify an IGI certificate online?
Go to igi.org, Verify a Report section, and enter the 9-digit number on your certificate. You will immediately access the official record of your diamond.
Does laser inscription damage the diamond?
No. The inscription is superficial and microscopic. It does not in any way affect the strength, brilliance, or value of the stone. It is standard on all IGI certified diamonds.
Can I have my Diamelys diamond verified by an external gemologist?
Absolutely. An independent gemologist can confirm the characteristics of your stone using the IGI number and inspection equipment.
What if the number on my certificate does not appear on the IGI website?
Contact the seller immediately to request an explanation. If the answer is unsatisfactory, do not accept the jewelry.
A question about your diamond or certificate? Contact our team →
