GIA Cut Grading System

Using a predictive computer model GIA bases their cut grading on the combination of face-up appearance design and craftsmanship. GIA do not assign a grade of Ideal Cut. The highest grade assigned by GIA is Excellent.

Ideal Cut Standards as applied by the cutters of Super Ideal Cut are not always a sub grade of Excellent, they can also fall within GIA Very Good range.

GIA Cut grade includes ratings of Excellent, Very Good, Good, Fair and Poor

AGS Cut Grading System

The AGSL determines cut grade using light performance, proportion, and finish characteristics to determine a diamond's fire and brilliance. When the AGSL determines a diamond's cut grade, they look at a combination of 11 different criteria in these three categories

 Using a combination of 11 criteria and including the inverse relationship between crown and pavilion angles, AGS determines cut grade by light performance, proportion and finish.

AGS assign cut grades of Ideal, Excellent, Very Good, Good, Fair, and Poor

AGS uses light performance factors including software like DiamCalc, and the ASET scope,

 AGS Cut and Girdle grades

Note: The HCA (Holloway Cut Adviser) is not a selection tool but a excellent aid to eliminate poor cuts especially when used together with an Ideal-Scope or AGS ASET Scope.

Desktop ASET

Hand Held ASET

Ideal-Scope