Accredited Gemologists Association 
is a nonprofit research, education and ethics organization benefiting professional and avocation gemologists as well as consumer interest

American Gem Trade Association 
the AGTA is an association of US and Canadian colored gemstone and cultured pearl industry professionals dedicated to promoting the natural colored gemstone trade

Asian Institute of Gemological Sciences (AIGS)
located in Bangkok, Thailand, founded in 1978 as Southeast Asia's first educational and research institute devoted exclusively to the training of students in the scientific and practical aspects of gemology and the gem trade

Association Française de Gemmologie
French organization of gemmologists, editors of the journal "Revue de Gemmologie"

Canadian Gemmological Association 
Canada's professional organization for the practice of gemmology. Website contains information about the organization, including information on membership, products, meeting times, annual Gem Conferences and more. 

Europe’s leading institute for training and research concerning gemmology since 1932

Far East Gem Institute 
Singapore  based gemological institute, laboratory and gemology courses

L'Ecole des Gemmes 
Centre de formation qualifiante en gemmologie. Allied teaching center of the Gemmological Association of Great Britain in France.

Expert Diamond 
Survey work: diamonds, precious stones, minerals, jewels, cutting tools and laboratory instruments. Prospection and transfer of technology. Basic training of personnel, lectures. 

Gemlab Inc. 
Research and development high-tech gem treatment laboratory, short courses in gem treatments, fabrication of gem instruments and gem treating equipment, books, etc.

Gemmological Association and Gem Testing Laboratory of Great Britain
gives details of courses, tutotials, workshops, exam details and dates, trips and other special events, lectures etc.

Gemmological Association of Australia 
Australia’s traditional gemmological educator since 1945 
general information on gemmology in the French language 

Gemmology in Scotland 
Scottish Branch of the Gemmological Association 

Gemmology World 
Canadian Institute of Gemmology

Gem Nantes Gemmologie à Nantes 
diverses formations en gemmologie (DUG et programmes courts) et les activités de recherche scientifique en gemmologie

The Gemology Project 
non-profit gemstone and gem science wiki-style database for anyone interested in gemstones and gemology 

Gemstone Identification Chart 
analyze the results got with the refractometer, polariscope, dichroscope, spectroscope, UV light, dichromatic filter, density scale, microscope and loupe, hardness tester

is an online guide to gemstone prices 

GIA - Gemological Institute of America
the world’s largest and most respected nonprofit institute of gemological research and learning 

HRD (Hoge Raad voor Diamant) 
Diamond High Council, Antwerp, Belgium

Institut National de Gemmologie 
The National Institute of Gemmology teaches over 500 persons a year and gives certifies over 100 persons each year (Brevet Professionnel, FEEG, Diploma of ING)

Instituto Gemológico Español 
Spanish gemological institute

International Colored Gemstone Association
a non-profit association to represent the international gemstone industry

International Gem Society
dedicated to bringing quality information and educational services to everyone interested in gemstones

Laboratoire français de Gemmologie 
French gemological laboratory in Paris 
information on gemstones, collector stones and rare facetable minerals

Russian Gemological Server 
information on business, research and educational projects in gemology

Swiss Gemmological Institute 
part of the Swiss Foundation for the Research of Gemstones, founded by trade organisations in 1974 and works independently on a scientific basis