Consisting of 11 grades, 0 being best, 10 worst. The way a diamond is cut greatly effects its sparkle, fire and brilliance - even its perceived size. Five measurements determine the cut grade of a diamond. The diagram at the left shows the angles and percentages of the AGS 0 cut diamond - the very best. Any deviation will cut grade, the brilliance and quite dramatically, the price. For example, the price difference between the best stone (AGS 0) and the worst (AGS 10), assuming color, clarity and weight are equal can be as much as 55%.

TERMINOLOGY
The TABLE is expressed as a percentage of the total diameter.
The CROWN is expressed as an angle.
The PAVILION depth is expressed as a percentage of the total diameter.
The thickness of the GIRDLE is expressed as a variation from extremely thin to extremely thick.
The CULET is from pointed (no culet) to extremely large.