Diamond Guides

Diamond Cut

The way a diamond is cut, exposes it’s brilliance and light. The way the diamond cut grade is evaluated, is looking at the proportions of facets that influence how the diamond looks, face up. The cut is determined by 3 factors: brilliance, fire and scintillation.

The GIA Diamond Cut Scale for standard round brilliant diamonds in the D-to-Z diamond color range contains 5 grades ranging from Excellent to Poor (GIA).

Excellent

The diamond, which has an even pattern of bright and dark areas, scores in the top category for all grade-setting determinants.

Very Good

This diamond’s grade is determined by brightness, scintillation, and polish. Although no individual proportions would necessarily cause its brightness or scintillation to perform poorly, the combination of this particular set of proportions leads to increased darkness in the pavilion mains.

Good

This diamond’s grade is limited by its scintillation. In this case, the somewhat shallow pavilion angle produces dark pavilion mains.

Fair

This diamond’s grade is limited by its scintillation. The combination of a shallow crown angle and a somewhat shallow pavilion angle leads to a face-up appearance with a lack of contrast and general darkness.

Poor

This diamond’s grade is limited by its weight ratio. Although most of the proportions for this diamond are fairly standard, the extremely thick girdle greatly increases the total depth. Therefore, this diamond’s diameter is much smaller than its carat weight would indicate.