IGI certification is an independent grading report issued by the International Gemological Institute that documents the exact cut, colour, clarity, and carat weight of a diamond - including lab-grown diamonds - using standardised laboratory conditions and equipment. For any lab-grown diamond purchase, insisting on an IGI or GIA certificate is non-negotiable - it is the only way to independently verify you are receiving the quality you are paying for.
An IGI certificate confirms the stone's measurable properties as assessed by a qualified gemologist, independent of the retailer selling it. Every lab-grown diamond sold by Dileti includes an IGI certificate issued before the stone is set, included in the purchase price at no additional charge.
What Is the International Gemological Institute?
The International Gemological Institute (IGI) is one of the world's largest independent diamond grading laboratories, founded in Antwerp in 1975. IGI operates grading facilities in Antwerp, New York, Mumbai, Hong Kong, Bangkok, Dubai, Tokyo, and Tel Aviv - processing more than one million diamonds and pieces of jewellery annually.
IGI's headquarters and primary grading operations remain in Antwerp - the same city where Dileti is based and where every Dileti diamond is quality-checked before setting. Dileti submits each stone to IGI grading independently of the manufacturer, ensuring the certificate reflects an objective third-party assessment rather than a self-certified quality claim.
What Is an IGI Certificate Document?
Every IGI diamond grading report documents the following for each individual stone:
- The 4Cs: Cut, Colour, Clarity, and Carat Weight.
- Origin: "Laboratory-Grown" - confirming the stone is not a natural mined diamond.
- Growth method: HPHT (High Pressure High Temperature) or CVD (Chemical Vapour Deposition).
- Measurements: Length × width × depth in millimetres.
- Certificate number: A unique 9-digit alphanumeric code verifiable directly on IGI's website.
IGI vs GIA: What Is the Difference for Lab-Grown Diamonds?
| Feature | IGI | GIA |
|---|---|---|
| Founded | 1975, Antwerp | 1931, USA |
| Lab-grown grading since | 2007 | 2020 |
| Lab-grown grading volume | Highest globally | Lower |
| 4Cs methodology | Identical to natural | Identical to natural |
| Industry status | Primary standard in Europe | Equally reliable |
Why Does IGI Certification Matter Specifically for Lab-Grown Diamonds?
Lab-grown diamonds can be produced across a wide range of quality levels. Without an independent certificate, a buyer has no way to verify the quality. IGI certification provides an independent, verifiable quality record that ensures:
- The stone is a real diamond, not a simulant.
- The stone is laboratory-grown, not a mined diamond.
- The growth method (HPHT or CVD) is documented for transparency.
- The exact specifications allow for fair price comparisons across retailers.
How to Verify an IGI Certificate
Every IGI certificate can be verified at igidiamond.com using the unique certificate number.
- Locate the IGI certificate number on the physical document or the laser inscription on the diamond's girdle.
- Visit igidiamond.com and enter the certificate number.
- Confirm the 4Cs grades, measurements, and origin match the physical certificate.
Frequently Asked Questions
Q1. What does IGI certified mean on a lab-grown diamond?
It means the stone has been independently graded by IGI and its characteristics are documented on a verifiable, non-transferable certificate.
Q2. Is IGI certification as good as GIA for lab-grown diamonds?
Yes. Both use identical 4Cs grading methodology and are considered fully reliable by European gemologists.
Q3. Does the growth method affect quality?
No. HPHT and CVD result in chemically identical diamonds; quality is determined entirely by the 4Cs grading outcome.
Q4. Is IGI certification worth insisting on?
Yes, always. It is the only way to independently protect your purchase and ensure you are receiving the exact quality described.
