Lab-Grown Diamond Guide
How to Look Up and Verify an IGI Certificate
Verify an IGI report number, compare the stone's specifications and laser inscription, and check that the report matches the diamond you are buying.
How do you look up an IGI certificate? The answer is a checking process that takes a few minutes. It helps you establish whether the report you have been shown exists in IGI's records and whether the stone specifications in the report match the product you are buying.
What Is an IGI Certificate?
IGI is one of the gemological organisations that prepares independent grading reports for gemstones, including natural and lab-grown diamonds. A report may include the diamond's laboratory origin, shape, measurements, carat weight, colour and clarity grades, as well as polish and symmetry.
Although commonly called a “certificate”, the document is essentially a grading report; it does not guarantee the stone's market price or future resale value.
1. Find the Report Number
The IGI report number appears at the top of the document. Ask the seller for a legible photograph or digital copy. When entering the number, check spaces, hyphens and letters as they appear in the document.
2. Use the Official IGI Verification Page
Look up the report number only on IGI's official report verification screen. The results should show the report date and basic stone information. If no result appears, check the number again; if it still cannot be found, ask the seller for an explanation before buying.
3. Compare the Digital Report with the Product Details
Opening a lookup result is not enough on its own. Compare each of these fields with the product page and the stone you will receive:
- The lab-grown diamond designation
- Shape and cutting style
- Carat weight
- Millimetre measurements
- Colour and clarity grades
- Polish and symmetry
- Fluorescence information
- The production method and any post-growth treatment description, if provided
If the carat weight, measurements or shape differ in particular, the document may belong to another stone.
4. Check the Laser Inscription
Many diamonds with reports have the report number laser-inscribed on their girdle. This inscription may not be visible to the naked eye; suitable magnification and correct lighting are needed. A jeweller or gemologist can show whether the number in the report matches the inscription on the stone.
Not seeing the laser inscription does not always mean the stone is fake. The setting may cover it, the angle may be unsuitable, or the relevant report may not include an inscription. In that case, check the report's “inscription” field.
5. Do Not Rely Solely on the QR Code
A QR code on the document can make verification faster, but check the domain name of the page it opens. A copied QR code can lead to another report. The safest method is to open the official website yourself and enter the report number manually.
6. Confirm That the Report Will Be Delivered with the Stone
Before buying, ask whether a printed or digital copy of the report will be provided with the product. If you are buying a centre stone mounted in a ring, including its report number on the invoice or product document makes it easier to track.
How to Read the Main Fields in an IGI Report
Shape and Cutting Style
This describes the stone's shape, such as round, oval, radiant or emerald, and its facet arrangement.
Measurements
These are length, width and depth in millimetres. They are as important as carat weight for understanding the visible surface on the finger.
Carat Weight
This is the stone's weight, not its diameter or quality grade.
Color and Clarity
These show colour and clarity grades. Assess them alongside cut, dimensions and budget.
Polish and Symmetry
These concern surface finish and the geometric alignment of the facets. See the Cut, Polish and Symmetry guide to learn about cut details.
What Should You Do If the Lookup Returns No Result?
- Check the number on the document again.
- Pay attention to letters, hyphens and the similarity between zero and O.
- Confirm that the report was actually issued by IGI.
- Ask the seller for the official digital report link.
- Do not pay until the match between the stone and report is clear.
Certificate Verification Checklist
- Was the official IGI domain used?
- Does the report number return a result?
- Is the laboratory origin clearly stated?
- Do carat weight, shape and measurements match the product?
- Are colour and clarity details the same?
- Does the laser inscription match the report?
- Will the report be delivered with the product?
See the international diamond certificate guide for more information about document types and the certified lab-grown loose diamonds page to compare reported stones.
Frequently Asked Questions
Can an IGI certificate be checked online?
Yes. Entering the report number on IGI's official verification screen lets you check the record and basic specifications.
Does an IGI report prove that a stone is real?
The report explains the identity and quality characteristics of the stone examined. For a secure purchase, the report record, laser inscription on the stone and product details should all be matched.
Can the laser number be removed?
It is permanent under normal wear, but recutting or extensive work on the girdle area can affect the inscription.
Does every lab-grown diamond have an IGI report?
No. Small side stones may not be reported individually. An independent report is an important comparison tool, particularly for centre stones.
Quick Summary of IGI Report Verification
- Copy the complete report number from the document.
- Open IGI's official report verification page yourself.
- Match carat weight, shape and millimetre measurements to the product.
- Compare colour, clarity, polish and symmetry.
- Check laboratory origin and any CVD, HPHT or post-treatment description.
- Where possible, verify the laser number on the girdle under magnification.
If a Report Record Exists but the Specifications Differ
A result for the report number is not enough on its own. If carat weight, measurements or shape do not match the product, the document may belong to another stone. Do not pay until the match is clear.