IGI Certification Explained: What to Look For on Your Diamond Certificate

What is IGI?

The International Gemological Institute (IGI) is one of the world's largest and most respected diamond grading laboratories. Founded in Antwerp in 1975, IGI has labs in Mumbai, New York, Hong Kong, and other major diamond centres. They grade both mined and lab-grown diamonds using the same rigorous standards.

The 4Cs: What Your Certificate Actually Grades

1. Carat Weight

The physical weight of the diamond, measured in carats (1 carat = 0.2 grams). Larger diamonds are exponentially rarer and more expensive. A 1-carat diamond costs far more than twice the price of a 0.50-carat diamond of the same quality.

2. Cut (The Most Important C)

Cut refers to how well the diamond's facets interact with light. Grades range from Excellent to Poor. An "Excellent" cut diamond will have maximum fire, brilliance, and scintillation — it's what makes a diamond truly sparkle. We recommend always prioritising cut over carat size.

3. Colour

Diamond colour is graded from D (completely colourless) to Z (noticeable yellow tint). For most people, diamonds in the D-G range appear colourless to the naked eye. Once set in gold, even H-I colour diamonds look stunning because the warm gold setting compensates.

4. Clarity

Clarity measures internal imperfections (inclusions) and surface blemishes. Grades range from FL (Flawless) to I3 (visible inclusions). For the best value, we recommend VS1-VS2 clarity — these diamonds appear perfectly clean to the naked eye but cost significantly less than VVS or FL grades.

Laser Inscription: Your Diamond's Fingerprint

Every IGI-certified diamond has a microscopic laser inscription on its girdle (the widest edge). This inscription matches the certificate number, making it impossible to swap your diamond. You can verify it under a jeweller's loupe or even a powerful phone camera macro lens.

How to Verify Online

Every IGI certificate has a unique report number. Visit igi.org and enter the number to instantly verify your diamond's grades, see the original certificate, and confirm authenticity. We include this certificate with every Noore Jewels diamond ring.