The International Gemological Institute
The International Gemological Institute (IGI) is one of the world's largest and most respected independent gemological laboratories. Founded in 1975 and headquartered in Antwerp, Belgium, IGI has certified millions of diamonds and gemstones across the globe.
When a diamond carries an IGI certificate, it means it has been independently examined, tested, and graded by expert gemologists — with no affiliation to the seller.
At Carbon & Clarity, every single diamond we use is IGI certified. No exceptions.
1975
Founded
Antwerp
Headquartered
Global
Independent Standard
Our Certifications
What's On Your Certificate
Each IGI certificate documents the exact quality characteristics of your diamond — known as the 4Cs:
| What's Graded | What It Means |
|---|---|
| Carat Weight | The precise weight of the diamond |
| Cut | How well the diamond has been shaped and faceted (Excellent / Very Good / Good) |
| Colour | The presence or absence of colour on a D–Z scale (D being completely colourless) |
| Clarity | The presence of inclusions or blemishes (FL to I3 scale) |
| Shape | Round Brilliant, Oval, Pear, Cushion, etc. |
| Measurements | Exact dimensions in millimetres |
| Polish & Symmetry | Quality of surface finish and facet alignment |
| Fluorescence | Whether the diamond glows under UV light |
| Report Number | A unique ID verifiable online at igi.org |
Your Assurance of Authenticity
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No Guesswork
The certificate tells you exactly what you are getting — every quality detail is documented in writing by a neutral third party.
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Verified Independently
The grading is done by IGI's gemologists, not by us. You can verify your certificate number directly on the IGI website at any time.
◻
Protects Your Investment
An IGI certificate is internationally recognised and is often required for insurance, resale, or gifting purposes.
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Specific to Lab-Grown Diamonds
IGI has a dedicated grading system for lab-grown diamonds, clearly noting the growth method (CVD or HPHT) on the certificate. This is the global standard.
Check Your Diamond Online
Every Carbon & Clarity diamond comes with a physical or digital IGI certificate. To verify yours:
Visit
igi.org
Click
"Verify Your Report"
Enter your IGI Report Number
View the full grading details of your specific diamond