About GIA A Tradition Of Science and Education

Established in 1931, GIA is the world’s foremost authority on diamonds, coloured stones and pearls. A public benefit, non-profit institute, GIA is the leading source of knowledge, standards and education in gems and jewellery.

Welcome to GIA.



Students around the globe turn to GIA for the knowledge, skills and credentials that launch successful gem and jewellery careers.



The world leader in gemmological research, GIA’s breakthrough discoveries deepen our understanding of gemstones and the world.



Through research, education, and unbiased gem grading and analysis, GIA strives to protect the gem and jewellery buying public by setting global quality standards.


history of gia

Since the 1930s, GIA researchers have made many innovative contributions to the understanding of gems.

  • 1931

    Robert M. Shipley establishes GIA; opens first U.S.-based gemmology correspondence course.

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  • 1931

    Home-study courses introduced, leading to the professional designation: Certified Gemmologist.

  • 1934

    Shipley publishes first issue of Gems & Gemology. Gemmology becomes a recognised science.

  • 1934

    GIA patents a loupe with triple aplanatic lens: the modern professional jeweller’s loupe is born.

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  • 1937

    GIA patents the first gemmological microscope. Gemmologists are able to examine the interior of gems.

  • 1940

    Richard T. Liddicoat joins GIA. Known as the “father of modern gemmology” for contributions to gems, jewellery.

  • 1947

    G. Robert Crowningshield joins GIA. Named VP of GIA Gem Trade Laboratory in New York shortly after.

  • 1947

    The first edition of Liddicoat’s Handbook of Gem Identification published; 11 editions follow.

  • 1948

    The first Graduate in Gemmology diploma is issued.

  • 1949

    GIA NY laboratory offers pearl identification service.

  • 1953

    Liddicoat’s International Diamond Grading System, based on Shipley’s 4Cs, becomes universal standard.

  • 1953

    GIA issues first diamond grading reports; they become the international jewellery industry’s benchmark.

  • 1956

    Crowningshield accomplishes ground-breaking work in the detection of gem treatments through the use of the spectroscope.

  • 1960

    The GIA Diamond Dictionary - which quickly becomes the international industry reference – is published.

  • 1965

    GIA courses accredited by National Home Study Council (now the Distance Education Training Council).

  • 1971

    GIA courses translated and taught in Japan

  • 1973

    On-campus classes accredited by National Association of Trade and Technical Schools.

  • 1982

    Gems & Gemology is redesigned, printed in full colour and goes on to win 15 awards for excellence during the next 20 years

  • 1982

    GIA Celebrates its 50th Anniversary with the first International Gemological Symposium

  • 1982

    The GIA Alumni Association is established.

  • 1987

    Liddicoat Gemmological Library and Information Centre acquires world’s largest collection of gemmological books.

  • 1988

    GIA grades the famous 45.52-carat Hope Diamond.

  • 1989

    GIA opens school in Korea; others follow in Europe, Asia and India.

  • 1991

    GIA hosts first annual Careers Fair, the industry’s pre-eminent recruiting event.

  • 1996

    Gems & Gemology publishes groundbreaking article on identifying synthetic diamonds.

  • 1997

    GIA opens Robert Mouawad Campus as its global headquarters in Carlsbad, CA.

  • 1999

    Robert M. Shipley (1887-1978) named Person of the Century by JCK magazine.

  • 1999

    GIA, De Beers researchers identify criteria for High Pressure/High Temperature processed diamonds.

  • 2003

    GIA identifies beryllium-diffused sapphires and rubies and chemical vapour deposition (CVD) synthetic diamonds.

  • 2005

    GIA introduces a cut grade for round brilliant diamonds in the D-to-Z colour range.

  • 2007

    GIA introduces Synthetic Diamond Grading Report.

  • 2007

    GIA creates 4Cs and International Diamond Grading System™ materials for consumers.

  • 2008

    GIA opens laboratories in Mumbai, Johannesburg and Gaborone.

  • 2009

    GIA offers gemmology courses entirely online.

  • 2011

    GIA offers interactive 4Cs app for consumers.

  • Timeline event 2012 Hero


    GIA opens laboratories in Tokyo and Ramat Gan, Israel.

  • 2014

    Susan Jacques becomes GIA’s sixth President and CEO

  • 2014

    GIA Develops DiamondCheck to differentiate natural from treated and synthetic diamonds

  • 2014

    GIA Inaugurates New York Laboratory and Education Facility


In the 1940s, GIA established the "4Cs" and the International Diamond Grading System™ – to this day, the worldwide standard for evaluating diamond quality.


The sparkle and brilliance of a diamond depends more on its cut than anything else.

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The absence of inclusions and blemishes makes a diamond rare and affects value.

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Diamonds in the D-to-Z colour range are valued by how closely they approach colourlessness – the less colour, the higher their value.

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Diamonds and gemstones are weighed in metric carats: one carat is equal to 0.2 grams, about the weight of a paperclip.

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Featured Events

Careers Fair

GIA Jewellery Careers Fair London

London, UK


A large scoop of rough diamonds.

Consumer Confidence and Jewellery Sales On the Rise

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Wedding couple: Groom in black tuxedo and woman in white gown hold hands and gaze at one another. California hills in the background.

Love in Tucson: The ‘Stars Aligned’ for Geologist and Designer at GIA Alumni Party

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