Many diamonds can appear to be colorless, but in fact most diamonds have some color. In the 1950’s, the Gemological Institute of America developed a standardized system to grade diamond color which is used today by the entire industry. Using the letters D-Z to indicate the grade, color is measured on a scale from colorless to light yellow, with colorless being the rarest and most valuable. The American Gem Society (AGS) also has a color scale which assigns the numbers 1-10 to indicate the grade.

Completely colorless diamonds are pure carbon, and are very rare. They are unequalled in fire and brilliance. Diamonds with even a hint of color owe it to “impurities” contained within the carbon when the diamond was formed. Elements such as nitrogen add tinges of yellow or brown. The more yellow the diamond the lower the color grade, and generally the brilliance decreases as the grade decreases. Fancy color diamonds are the exception.

D
Completely colorless and extremely rare, with stunning brilliance and fire.

E
The barest hint of color only detectable by an expert gemologist in laboratory conditions. Also rare, its brilliance is surpassed only by a D color grade diamond.

F
A slight tinge of color not detectable to the naked eye. A very high quality diamond with excellent brilliance.

G/H
More color, but noticeable only when compared to a D or E grade. An excellent value high quality diamond.

I/J
Color which is easier to see, especially when set in white gold or platinum. A well cut good clarity diamond in an I/J color grade will still posses excellent brilliance.

K/L/M
Color can be clearly seen with the naked eye.

N-Z
Definite yellow or brown color. A low quality diamond.