Clarity describes the clearness or purity of a diamond. This is determined by the number, size, nature, and location of the internal (inclusions) and external (blemishes) imperfections.

Cut refers to the proportions, finish, symmetry, and polish of the diamond. These factors determine the fire and brilliance of a diamond. Well cut diamonds sell at a premium and poorly cut diamonds sell at discounted prices. With the advent of technology, the cut of the diamond can be determined through the use of the Dia-Mension system, a computerized system which takes accurate measurements and proportions of a diamond in seconds, in addition to the standard millimeter gauge.

As an example, a round brilliant cut, which has 58 facets, is shown below. Since the quality of the cut is directly responsible for the stone’s beauty, the precision with which the facets are arranged is of prime importance. They determine the amount of light reflected to the eye, called brilliance.

The proportions displayed by the stone are very significant. Two of the key factors in the grading of cut quality — table percentage and depth percentage — are usually expressed on grading reports. Measurement of three different parameters allows for easy calculation of these percentages by using the formulas expressed below.

Carat Weight is the unit of weight for the diamond. A carat is further subdivided in 100 points ( 0.01 carat = l point ). One carat is equal to 0.20 grams. Value per carat increases with carat size, because larger rough diamonds occur less frequently. In other words, 2 half-carat diamonds taken together will not cost as much as 1 one-carat diamond, as the one-carat stone is more rare.

A diamond's color grade is based on how noticeable the color is, GIA refers to this as the D-Z range, also known as the depth of color. The difference in color grade can have a significant impact on price and appearance.

D-E-F : These grades are considered colorless, D and E diamonds have virtually no color, and an F has a nearly undectable amount of color that shows only in the facedown position. The differences between these grades are actually very slight, in diamonds smaller then .25 ct. they are almost indistinguishable. Diamonds in this color range are extremely rare and valuable.

G-H-I-J : These grades are near-colorless. Diamonds with these grades look colorless face-up and nearly colorless face-down. They might have slight traces of color that aren't noticeable to to the untrained eye when the stone is mounted. * All Sheiban Diamonds are a Grade I or better.

Grades K and below : These Diamonds present from faint to light yellow cast. Once a diamond goes beyond the Z color range it enters the fancy color range starting with Fancy Light Yellow.

GIA'S strict guidelines for each color range make communication about diamond color dependable and accurate. A GIA graded F-color Diamond is an F-Color Diamond, no matter where you are. **Your diamond should always be accompanied by a GIA grading certificate.