The Diamond 4Cs

The Diamond 4Cs: Color, Clarity, Cut, and Carat Weight

The Gemological Institute of America (GIA) was founded in 1931. GIA created the 4Cs (Color, Clarity, Cut and Carat Weight) as a universal method for establishing the quality of any diamond, anywhere in the world. Now diamond quality can be described in a universal language and diamond customers can know exactly what they are buying.

Color Scale:
In 1953, GIA introduced the D-to-Z color scale for grading the color of diamonds from colorless to light yellow. The letter “D” was chosen for the top grade (colorless).

Clarity Scale:
The GIA Clarity Scale today has six categories ranging from Flawless to Included and contains 11 specific grades. A gemological microscope is used for clarity grading to plot the inclusions and blemishes in all diamonds when a GIA Diamond Grading Report is requested.

Cut Scale:
The GIA Cut Scale ranges from Excellent to Poor. It tells how successfully a diamond interacts with light to deliver the brilliance, fire, and brightness of the diamond. It also assesses the overall cut quality, taking into account such features as proportions, table size, polish and symmetry.

Excellent
Very Good
Good
Fair
Poor

Carat Weight:
The carat weight has been used in the gem trade since antiquity, but the weights differed between locations. In 1907, the use of the metric carat began. The carat is subdivided into fractions or decimals. Small diamonds are weighed in points and 0.01 carats (ct) equals 1 point. Small brilliants with a weight of .07 – .15 carats are called Melees.

(Appoximate sizes for round diamonds)