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.

EDUCATE

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

LEARN MORE

RESEARCH

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

LEARN MORE

PROTECT

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

LEARN MORE

CREATOR OF THE 4Cs

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

Cut

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

Learn More

Clarity

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

Learn More

COLOUR

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

Learn More

CARAT WEIGHT

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

Learn More