IGI Certified Diamonds — From Antwerp
Every IGI certified diamonds purchase from Diamantwerp gives you direct access to stones graded by the International Gemological Institute — the world's largest gemological laboratory, founded in Antwerp in 1975. IGI certified diamonds offer the most accessible entry point into certified quality: the same rigorous 4C grading at the best price point in the market.
About GIA
What Are IGI Certified Diamonds?
The International Gemological Institute was founded in Antwerp in 1975, making it one of the city's original contributions to the global diamond certification industry alongside HRD. Today, IGI has grown into the world's largest independent gemological laboratory — with more than 20 laboratories across Antwerp, New York, Hong Kong, Mumbai, Tokyo, Dubai, Bangkok, and beyond.
IGI assesses diamonds using the internationally accepted 4C framework — Cut, Colour, Clarity, and Carat weight — the same system used by GIA and HRD. Every IGI certified diamond receives a unique report number, laser-inscribed on the diamond's girdle, that can be verified for free at igiworldwide.com.
IGI has become the dominant lab for lab-grown diamond certification — grading the majority of lab-grown stones sold worldwide. For natural diamonds, IGI offers excellent value: rigorous, internationally recognised certification at a more accessible price point than GIA, making it the ideal choice for buyers who want the assurance of independent grading without the GIA premium.
IGI — Key Facts
Founded
Laboratories
Lab-grown lab
Report Check
IGI was born in Antwerp in 1975 — the same diamond district where Diamantwerp has operated since 1987. IGI certified diamonds from our inventory carry genuine Antwerp provenance.
With 20+ labs across 6 continents, IGI certificates are recognised and accepted by jewellers, insurers, and buyers worldwide.
IGI is the world's leading certification lab for lab-grown diamonds — grading the majority of lab-grown stones sold globally. For lab-grown, IGI is the industry standard.
IGI Laboratory Locations
Lab Comparison
IGI vs GIA vs HRD — How Do They Compare?
All three labs Diamantwerp works with are independent, internationally respected, and use the same 4C framework. The differences lie in grading strictness, global recognition, price, and turnaround time.
| Criteria | GIA | HRD Antwerp | IGI |
|---|---|---|---|
| Founded | 1931, USA | 1973, Antwerp | 1975, Antwerp ✦ |
| Type | Non-profit | Private | Private |
| Grading strictness | Most strict | Strict | Slightly more lenient |
| Global recognition | Highest worldwide | High (esp. Europe) | High, rapidly growing |
| Antwerp connection | Lab in Antwerp | HQ in Antwerp | Founded in Antwerp ✦ |
| Lab-grown diamonds | Yes, graded | Yes, graded | ✓ World #1 lab |
| Global laboratories | 15+ | Antwerp only | 20+ on 6 continents |
| Free online verification | ✓ gia.edu | ✓ hrdantwerp.com | ✓ igiworldwide.com |
| Typical premium vs IGI | +5–15% | +3–10% | Baseline (most accessible) |
| Best for | Maximum trust, resale value, international buyers | European buyers, Antwerp provenance | Best value, lab-grown, maximising carat |
✦ IGI was founded in Antwerp in 1975 — the same diamond district where Diamantwerp has operated since 1987. More about GIA → More about HRD →
Read our full GIA vs HRD vs IGI comparison guide →Education
How to Read your IGI Certified Diamonds Report?
Every IGI certified diamonds report follows the same structure. Here's what each field means — and what to look for when you receive yours.
Sample IGI Grading Report
What the IGI Report Contains
An IGI certified diamonds grading report is issued after examination by multiple trained gemologists at IGI's Antwerp laboratory — with no commercial interest in the outcome. It objectively describes every quality characteristic of the stone across all 4Cs.
Report Number — Unique identifier, laser-inscribed on the girdle. Verify free at igiworldwide.com or scan the QR code on the report.
Colour Grade — D to Z scale. G–H recommended for best value. Colour guide →
Clarity Grade — FL to I3. VS2 and SI1 are eye-clean at most carat weights. Clarity guide →
Cut Grade — Excellent, Very Good, Good, Fair, Poor. Always choose Excellent — cut is the biggest driver of sparkle. Cut guide →
Diamond Origin — IGI reports for natural diamonds include a statement of natural origin. IGI lab-grown reports clearly state the diamond is laboratory-grown — full transparency on every certificate.
Why IGI Certified Diamonds Offer the Best Value
IGI certified diamonds are typically 5–15% below equivalent GIA-certified stones — making them the most accessible entry point into independently certified diamonds. At Diamantwerp, a 1-carat IGI certified diamonds starts from around €1,300, compared to €1,600+ for the equivalent GIA stone.
Our experts pre-select only the best-performing stones within each IGI grade — so you get maximum quality at the IGI price point.
Every IGI certificate carries a QR code and unique report number for instant free verification at igiworldwide.com — confirming the grades, the Antwerp origin, and that your certificate is genuine. The same number is laser-inscribed on the diamond's girdle.
Browse GIA Diamonds
IGI Certified Diamonds — Live Inventory
Browse our live inventory of IGI certified diamonds, updated daily from Antwerp's diamond district. Filter by carat, colour, clarity, and cut to find your ideal IGI certified diamonds at source prices.
Other Labs
Also Available — HRD & GIA Certified Diamonds
All our IGI certified diamonds are available alongside HRD and GIA certified options — letting you compare labs and choose the certification that best suits your needs and budget.
FAQ
Frequently Asked Questions — IGI Certified Diamonds
What does IGI certified mean for a diamond?
An IGI certified diamond has been independently graded by the International Gemological Institute — founded in Antwerp in 1975. IGI assesses the diamond's cut, colour, clarity, and carat weight using internationally accepted standards. The resulting grading report is an objective, third-party description of the stone's quality. With 20+ laboratories worldwide, IGI is one of the three most respected grading laboratories alongside GIA and HRD.
Is IGI certification as reliable as GIA?
IGI is one of the world's three most respected diamond grading laboratories. While GIA is generally considered the most conservative grader — and therefore carries the highest premium — IGI is widely accepted by insurers, jewellers, and buyers worldwide. For natural diamonds, IGI offers excellent value: the same rigorous 4C assessment at a more accessible price point. For lab-grown diamonds, IGI is the dominant certification lab — used by the majority of lab-grown diamond producers globally.
Are IGI certified diamonds cheaper than GIA?
IGI certified diamonds are typically the most accessible entry point into certified diamonds — usually 5–15% below equivalent GIA-certified stones. This makes them ideal for buyers who want certified quality at the best possible price, or who are maximising carat weight within a budget. At Diamantwerp, we source IGI certified diamonds directly from Antwerp's diamond district — so even compared to other IGI dealers, our prices are significantly lower.
How do I verify an IGI diamond certificate?
Every IGI grading report carries a unique report number, laser-inscribed on the diamond's girdle, and a QR code for instant mobile verification. You can verify any IGI report for free at igiworldwide.com — simply enter the report number or scan the QR code to confirm the grades and check the certificate is authentic.
Can I buy IGI certified diamonds directly from Antwerp?
Yes — Diamantwerp is based at Pelikaanstraat 62 in Antwerp's diamond district. IGI was founded in Antwerp in 1975 and maintains one of its largest laboratories in the same district. We offer IGI certified loose diamonds directly to private buyers and jewellers worldwide. By sourcing directly from the Antwerp market, you access the same IGI certified stones sold by high-street jewellers at up to 70% below their retail prices.
