ABOUT GIA
About GIA

A Tradition Of Science and Education

Established in 1931, the Gemological Institute of America (GIA) is the world’s foremost authority on diamonds, colored stones, and pearls. A public benefit, nonprofit institute, GIA is the leading source of knowledge, standards, and education in gems and jewelry. 

History of GIA

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

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.


Clarity

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


COLOR

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


CARAT WEIGHT

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

ABOUT GIA
About GIA

A Tradition Of Science and Education

Established in 1931, the Gemological Institute of America (GIA) is the world’s foremost authority on diamonds, colored stones, and pearls. A public benefit, nonprofit institute, GIA is the leading source of knowledge, standards, and education in gems and jewelry. 

History of GIA

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

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.


Clarity

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


COLOR

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


CARAT WEIGHT

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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