GIA, IGI and HRD certificates – comparison, differences and importance when purchasing

Update: August 28, 2025 • Reading time: ~10–12 min

A certificate is a diamond's "identity card." GIA, IGI, and HRD are the most common. Each report covers the 4Cs, but they vary in terms of grading rigor, recognition, and cost. For global purchases and insurance, GIA/HRD are the most reliable; IGI is more common for lab-grown diamonds. Always verify the report online and the number engraved on the diamond.

Why a certificate and what is in it?

The certificate independently confirms the 4C parameters (cut, color, purity, mass), as well as dimensions, proportions, polish, symmetry, fluorescence , a drawing/"map" of inclusions, and a report number (often laser-engraved on the girdle). It is an essential document for comparing offers, resale, and insurance.

4C + proportions – the key to appearance (surface, fire, contrast).
Fluorescence – information needed to assess appearance in real life.
Inclusion map – the actual “fingerprint” of the stone.
Inscription – report number on the rondist (online verification).

The three most popular institutes

GIA – the global reference point

The Gemological Institute of America is renowned for its consistent, rigorous grading and broadest commercial recognition. It is the "gold standard" in many markets.

HRD – European precision (Antwerp)

HRD Antwerp. Its assessment rigor is comparable to GIA, a popular choice in Europe. Well-recognized for insurance in the EU market.

IGI – wide presence, especially in lab-grown

International Gemological Institute. These reports are widely available in the market, especially for lab-grown diamonds, due to the scale and cost of certification. Recognition is growing globally, but in some markets, they are considered somewhat more lenient than GIA/HRD.

A Brief History of Institutes (Interesting Facts)

1931 – GIA (USA): Founded by Robert M. Shipley to standardize diamond grading for the jewelry trade. Later led by, among others, Richard T. Liddicoat ("father of modern gemology").

Interesting fact: GIA has educated global generations of gemologists (GG diploma).

1953–1955 – GIA creates the 4Cs : Cut, Color, Clarity, Carat system and D–Z color scale; in 1955, GIA issues the first modern grading reports.

1973 – HRD (Antwerp): an institute based in the European diamond trading centre, quickly gaining the trust of the EU market and insurers.

1975 – IGI (Antwerp): starts as a laboratory, today one of the largest independent players; popularizes, among other things, laser engraving of report numbers and mass certification also for laboratory diamonds.

Sources for in-depth research: GIA , GIA – history of 4C , IGI , HRD Antwerp .

GIA vs IGI vs HRD – Difference Table

Criterion	GIA	HRD	IGI
Rigorous 4C grading	Tall and consistent	High (close to GIA)	Moderate–high (depending on service)
Commercial recognition	Very high globally	High in Europe	Wide, strong in lab-grown
Typical use	Premium natural diamonds	Natural (EU market)	Lab-grown and broad market
Online verification	Yes (GIA Report Check)	Yes (HRD Verify)	Yes (IGI Verify)
Number on the rondiste	Yes	Yes	Yes

Note: Market practice is variable – the assessment of a specific report depends on the date, service, and type of stone. Always verify the specimen.

Microscope_diamonds_GIA

Checklist: What to Check in the Report Before Purchasing/Insuring

4C + proportions (Cut ≥ Excellent, transparent sheet, symmetry/polishing ≥ Very Good).
Fluorescence – strength and influence on appearance (with H-J it can be beneficial; with D-F, be careful).
Inclusion map – location under the surface vs. at the edge, type of inclusion.
Dimensions (diameter, depth, tabletop/table, girdle, culet) – are they within the recommended ranges?
Report number – engraving on the rondelle = compliance with the document.
Online verification – report in the institute's database (links below).

Download the checklist (PDF)

How to verify your certificate online (step by step)

Read the report number (from the document and from the rondist).
Visit the institute's website and use the report search engine:

GIA Report Check: gia.edu/report-check-landing
IGI Verify: igi.org/reports/verify-your-report
HRD Verify: my.hrdantwerp.com/verify

Enter the number and check if the 4C parameters, dimensions and photos match the stone.
If in doubt, contact our advisor. We'll double-check the report and the stone.

Michelson Recommendations – Which Certificate to Choose?

Engagement Ring / Resale : GIA or HRD.
Lab diamond : IGI acceptable; we ensure excellent cut and online verification.
Always : look at the cut and the placement of inclusions beneath the surface. The certificate is essential, but "how it shines" is what makes it so impressive.

FAQ – frequently asked questions

Is the IGI certificate “inferior” to the GIA?

IGI is widely used and has online verification. In some markets, it's considered a slightly more lenient grade than GIA/HRD, so it's always worth comparing specifications and seeing the stone in person.

Is HRD the same value as GIA?

HRD is highly regarded, especially in Europe, with grading rigor similar to GIA. In practice, both are accepted for purchase and insurance purposes.

Does every diamond have to be certified?

We recommend purchasing only those certified by a major institute (GIA/IGI/HRD). This protects the buyer and facilitates resale.

What's more important: the certificate or the live appearance?

A certificate is essential, but the delight comes from the cut, contrast, and clarity of the glass. Combine the two – that's why we invite you to inspect it in person.

How to recognize a false report?

Check the number in the institute's online database and verify the parameters. Make sure the number laser-engraved on the rondelle matches the document.