What Is The American Gem Society Grading System?
Diamond grading is a highly specialized field, but it doesn't have to be mysterious. Many consumers can distinguish between diamonds that are at extreme ends of the scale. True, when the calls are closer, it takes a trained professional grader to make the distinction.

Yet these distinctions can represent considerable differences in cost to you, the consumer. AGS members know that customers want to understand all the factors that influence the value of the jewelry they buy. For this reason, the American Gem Society has developed the AGS Diamond Grading System.

The AGS system grades three value factors: cut, color, and clarity. Each factor is evaluated on its own 0 to 10 scale. The scale begins at 0, the highest grade, and goes down to 10, the lowest. The three factors are expressed separately along with the carat weight of the stone for the final AGS Grade.

For example, the AGS Grade for a 1.25 carat diamond with a cut grade of 3, a color grade of 4, and a clarity grade of 2 would be expressed 3/4/2-1.25. To avoid confusion, the AGS Diamond Grading System always expresses characteristics in the same order: cut, color, clarity, and, finally, carat weight.