Color

With the exception of some fancy colored diamonds, the most valuable diamonds are those with the least color.
The color scale for transparent diamonds runs from D-F (colorless), G-J (near colorless), K-L (faint yellow),
to Z (slightly yellow). Completely colorless diamonds are rare.

Color	Description
D	The highest color grade and the diamond is absolutely colorless.
E	Colorless
F	Colorless
G - H	Near Colorless
I - J	Near Colorless
K - M	Faint Yellow
N - Z	Light Yellow to Yellow

When diamonds are formed with traces of other minerals, rare and beautiful colors can result.
These "fancy" colors range from blue and brilliant yellow to red, brown, pale green, pink, and violet.
Because of their rarity, colored diamonds are highly desirable and may be quite valuable.

Clarity

A diamond's clarity is measured by the existence, or absence, of visible flaws. Tiny surface blemishes or internal inclusions-even those seen only under magnification with a jeweler's loupe-can alter the brilliance of the diamond and effect its value. Clarity levels begin with flawless (F & IF) and move down to Very Very Slightly (VVS1 & 2), Very Slight (VS1 & 2), Slightly Included (SI1 & 2), and Included (I1, 2, & 3).

Cut

A proper cut is 1/3 of the value of a diamond. If the pavilion of a diamond is not a correct angle, it is not a perfect cut. When you think of the cut, you probably think of the shape of the diamond. That is partially correct. While cut does refer to the shape, it also refers to the proportions of how the diamond is actually cut.

 

100 points = 1 carat or 5 carats = 1 gram

Diamonds are cut into many different shapes, reflecting not only popular taste but the proportions and quality of the rough diamond. The most popular shapes include Round, Oval, Square, Princess, Emerald, Baguette, and Marquise cuts. Many specialty shapes are also available.

A diamond's overall proportions, as well as the size and placement of its many reflective surfaces or facets, also play a large part in "cut." The consistency and balance of these can greatly affect how the stone captures light and reflects it back to the eye.

Carat