Diamond Education: Certification

A diamond’s “certificate” is its grading report. Knowing which lab issued that report is important, since diamond grading is not standardized or regulated. Weight we can measure (1ct =0.2gr) just like proportions, dimensions, symmetry and fluorescence. For example; a diamond reported as F in colour at a known “soft” lab might receive G, H, or lower at a more reputable lab. Some labs don’t report all measurements. Some give no description or grade for cut. These differing standards and practices can be confusing for consumers.

Diamond House therefore supports the laboratories of GIA, HRD and AGS for all diamonds 1.00ct+

For all diamonds up to 0.99ct we recommend GIA-HRD-IGI, and AGS.


• The Diamond High Council
• International Gemmological Institute
• The Gemological Institute of America


The Diamond High Council

The Diamond High Council (Hoge Raad voor Diamant, HRD) is a non-profit organisation at the service of the Belgian diamond trade and industry.

The HRD not only acts as the representative and mouthpiece of the diamond sector, the various departments also offer the diamond community a wide range of services.

One of these is the HRD Certificates Department, founded in 1976 to meet the growing demand for reliable diamond certificates. At that time, a large number of diamond laboratories existed. Concerning nomenclature and grading methods, confusion reigned, which made it very difficult for the consumer and even for the professional diamond dealer to judge the value and meaning of a certificate.

It was set up in 1972 in cooperation with the Antwerp University ( Rijks Universitair Centrum Antwerpen, RUCA).

The HRD was not the only organisation to realize the importance of good quality descriptions. The World Federation of Diamond Bourses (WFDB) and the International Diamond Manufacturers Association (lDMA) also felt that a clear and well-founded system for grading polished diamonds was urgently needed.

In February 1996, the HRD Certificates Department was the first diamond lab in the world to be officially accredited according to the standards EN 45001, ISO/IEC Guide 25 and the relevant clauses of ISO 9002 for the quality examination of polished diamonds (Beltest certificate Nr. 047).

ISO 9002 is an international standard concerning management and quality systems.

Contact Information:
Diamond High Council-HRD
Hoveniersstraat 22
B - 2018 Antwerp

Tel: (32) 3 222 05 11
Fax: (32) 3 222 07 24
Email: info@hrd.be

Member Number Diamond House: 6012

International Gemmological Institute

Established in Antwerp, New York, Bangkok, Mumbai and Tokyo, IGI has now developed into the largest independent gem certification and appraisal institute renowned for its quality services, extensive experience and know-how.

The International Gemmological Institute (IGI), the oldest institute of its kind in Antwerp, was set up in 1975 and along with its sister laboratory in New York, is one of the leading gemological institutions in the world.

Today, a staff of just 3 has grown to over 500 professionals dedicated to a standard of excellence second to none in Antwerp, New York, Bangkok, Mumbai and Tokyo. Today IGI issues more than 1 mio reports a year.

Thousands of jewellers, retail stores, insurance companies, internet sales organizations, catalogue companies (mail order), accounting and securities firms and consumers are relying on the IGI reports.

IGI Past and Present
IGI was founded in Antwerp in 1975. Situated in the heart of the diamond district in this major hub of the diamond industry, IGI Antwerp has earned a reputation as an international authority in the scientific analysis and certification of diamonds and other precious stones. In 1980, IGI opened its laboratory in New York City to meet the increasing demand in the United States for gem certification.

Just one year later, International Gemmological Information, a division of IGI New York, was formed specifically for issuing independent gemological appraisals and identification reports for precious metal and gemstone jewellery.

In 1982, IGI started its own gemological school in Antwerp in order to share its knowledge and experience with other professionals and gem enthusiasts. The intensive diamond and colored stone courses have been attended by students from all over the world. Seminars are also organized in New York.

Today, IGI with its operations in Antwerp, New York, Bangkok, Mumbai and Tokyo is the largest independent, internationally established gem certification and appraisal institute in the world offering a full range of services for professionals, businesses and individuals throughout the world.

Contact Information:

IGI Belgium - World Head Office
Schupstraat 1
2018 Antwerp

Tel: +32-3-231.68.45
Fax: +32-3-232.07.58
Email: info@igiworldwide.com


The Gemological Institute of America, or GIA, is a nonprofit institute that is dedicated to research and education in the field of gemology and jewelry. Founded in 1931, GIA's mission is to protect all buyers and sellers of gemstones by setting and maintaining the standards used to grade the gemstone’s quality. The institute does so through research, gem identification and diamond grading services and a large variety of educational programs. Through its world-renowned library and experts on the subject, GIA acts as a resource of gem and jewelry information for the trade, the public and worldwide media outlets.

In 1953 the GIA developed its International Diamond Grading System and the Four Cs (cut, clarity, color, and carat weight) as a standard to compare and evaluate the quality of diamonds.

Today, the institute is headquartered in California (Carlsbad) and operates out of 14 countries, with 12 campuses, seven laboratories and four research centers worldwide.

Contact Information:

GIA World Headquarters
The Robert Mouawad Campus
5345 Armada Drive
Carlsbad, CA 92008
Call: +1 800 421 7250
Call: +1 760 603 4000

 Fax: +1 760 603 4080