The International Gemological Institute (IGI) is the world largest gemological laboratory by volume, known for its work in lab-grown diamonds and accessible certification. This guide explains IGI certification, how it compares to GIA, and when IGI certification is the right choice.
What is IGI?
The International Gemological Institute (IGI) was founded in 1975 in Antwerp, Belgium. It is the largest gemological lab in the world by number of certificates issued, with laboratories in 12 countries. IGI is particularly known for certifying lab-grown diamonds and is the preferred lab for many lab-grown diamond producers.
- Founded - 1975 in Antwerp, Belgium
- Type - Independent, for-profit
- Headquarters - Antwerp, Belgium
- Laboratories - 12+ countries (Antwerp, New York, Mumbai, Dubai, Hong Kong, Shanghai, etc.)
- Specialty - Lab-grown diamonds, fancy colored diamonds
- Volume - Largest by certificate count
IGI Diamond Grading
IGI grades diamonds using the same 4Cs framework as GIA (Color, Clarity, Cut, Carat Weight), but with some differences in grading strictness.
- Color - D-Z scale, same as GIA
- Clarity - FL-I3 scale, same as GIA
- Cut - Excellent to Poor (for round brilliants)
- Polish/Symmetry - Excellent to Poor
- Fluorescence - None to Very Strong
- Key difference - IGI may grade slightly more leniently than GIA, especially in color and clarity
IGI Report Types
| Report Type | For Diamonds | Cost | Features |
|---|---|---|---|
| IGI Diamond Report | Natural, all sizes | 30-100 dollars | Full grading, laser inscription |
| IGI Lab-Grown Report | Lab-grown, all sizes | 30-80 dollars | Identifies as lab-grown, full grading |
| IGI Colored Diamond Report | Fancy color diamonds | 50-200 dollars | Color origin (natural vs treated) |
| IGI Colored Stone Report | Ruby, sapphire, emerald | 40-150 dollars | Color, clarity, origin (optional) |
| IGI Jewelry Report | Mounted jewelry | 50-150 dollars | Grades stones in settings |
IGI and Lab-Grown Diamonds
IGI is the leading certifier of lab-grown diamonds. As the lab-grown market has exploded, IGI has become the standard certification for CVD and HPHT diamonds.
- Market share - IGI certifies approximately 70pct of lab-grown diamonds
- Identification - Clearly marks all lab-grown diamonds on reports
- Laser inscription - Inscribes "LABORATORY GROWN" on girdle
- Growth method - Identifies CVD vs HPHT
- Post-growth treatment - Detects HPHT treatment of CVD diamonds
- Why IGI for lab-grown - Faster turnaround, lower cost, specialized expertise
IGI vs GIA: Key Differences
| Factor | IGI | GIA |
|---|---|---|
| Founded | 1975 | 1931 |
| Type | For-profit | Nonprofit |
| Strictness | Slightly more lenient | Most strict/consistent |
| Lab-grown specialty | Yes (market leader) | Yes (but smaller share) |
| Cost | Lower | Higher |
| Turnaround | Faster | Slower |
| Resale value | Good | Highest |
| Recognition | Global, especially lab-grown | Global gold standard |
When to Choose IGI Certification
- Lab-grown diamonds - IGI is the standard and most cost-effective
- Budget diamonds - Lower certification cost reduces overall price
- Fashion jewelry - IGI is sufficient for non-investment pieces
- Colored diamonds - IGI has strong expertise in fancy colors
- Mounted jewelry - IGI offers jewelry reports for stones in settings
- Fast turnaround - IGI typically certifies faster than GIA
When to Choose GIA Over IGI
- Natural diamond engagement rings - GIA carries more prestige and resale value
- Investment diamonds - GIA certification is preferred by buyers
- High-value diamonds - Over 10,000 dollars, GIA is worth the extra cost
- Resale potential - GIA-certified diamonds sell faster and for more
- Color/clarity consistency - GIA grading is more consistent across graders
How to Verify IGI Reports
- Go to IGI website (igi.org/verify-report)
- Enter the IGI report number
- Enter the diamond carat weight (for security)
- View the digital report
- Compare with physical certificate
- Check laser inscription on diamond girdle
- Verify with a jeweler if purchasing high-value stones
IGI Colored Gemstone Certification
IGI also certifies colored gemstones, including ruby, sapphire, emerald, and semi-precious stones. IGI colored stone reports include:
Common Misconceptions About IGI
- Myth: IGI certification is fake or unreliable - Fact: IGI is a legitimate, respected lab; it may grade slightly more leniently than GIA but is not fraudulent.
- Myth: IGI only certifies lab-grown diamonds - Fact: IGI certifies natural diamonds, colored stones, and jewelry; lab-grown is just its largest segment.
- Myth: IGI diamonds are lower quality - Fact: The diamond quality is independent of the certifying lab; IGI just describes it.
- Myth: IGI reports cannot be verified - Fact: All IGI reports can be verified online at igi.org.
- Myth: IGI is only for cheap jewelry - Fact: IGI certifies diamonds of all values, including high-end fancy colored diamonds.
Frequently Asked Questions
What is IGI certification and how does it compare to GIA?
IGI (International Gemological Institute) is the world's largest gemological lab by volume, founded in 1975 in Antwerp. It uses the same 4Cs grading as GIA but may grade slightly more leniently, especially in color and clarity. IGI is the leading certifier of lab-grown diamonds (approximately 70pct market share). GIA is stricter, more consistent, and carries higher resale value for natural diamonds. IGI is more affordable and faster, making it ideal for lab-grown and budget diamonds.
Is IGI certification reliable for lab-grown diamonds?
Yes, IGI is the gold standard for lab-grown diamond certification. It certifies approximately 70pct of all lab-grown diamonds and has specialized expertise in identifying growth method (CVD vs HPHT), post-growth treatments, and clearly marking stones as laboratory-grown. IGI laser-inscribes 'LABORATORY GROWN' on the girdle of all lab-grown diamonds. For lab-grown diamond jewelry, IGI certification is both sufficient and appropriate.
Should I buy an IGI-certified natural diamond?
For everyday jewelry and fashion pieces, IGI certification is perfectly fine and offers better value. For engagement rings and investment pieces over 10,000 dollars, GIA certification is generally preferred due to stricter grading and higher resale value. If buying an IGI-certified natural diamond, verify the report online and consider having an independent appraiser confirm the grade, as IGI may be slightly more lenient than GIA.
How much does IGI certification cost?
IGI Diamond Report costs 30-100 dollars depending on carat weight. Lab-grown diamond reports cost 30-80 dollars. Colored stone reports cost 40-150 dollars. IGI is generally 30-50pct cheaper than GIA for comparable services. For wholesale jewelry, the per-stone certification cost is included in the product price, and IGI's lower cost helps keep wholesale prices competitive.
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