STRTING February 1, the American Gem Society Laboratories will begin issuing the Diamond QualityTM Document for the new American Gem Society (AGS) Performance-Based Cut Grade system for several shapes of the emerald cut.

The AGS Gemological Sciences Committee approved the AGS Performance Cut Grading System for three new shapes: square emerald cut, rectangular emerald cut and an octagon step cut.

“We’re very excited to announce the roll-out of these shapes,” says Peter Yantzer, Executive Director of AGS Laboratories. “The emerald cut is very popular with consumers, and for the industry this will hopefully mean an increase in sales at the counter.”

In 2005, AGS released their Performance-Based Cut Grading System for both the round brilliant and the princess — the first-ever cut grading system for a fancy shaped diamond.

The science supporting the Performance-Based Cut Grade System reflects AGS’s transition from a proportion-based to a performance-based cut grade system, where all facets of a diamond are measured in three dimensions rather than two dimensions. The Lab uses state-of-the-art ray tracing software to trace light traveling through a diamond. The software demonstrates the quantity and quality of the light being returned to the viewer. AGS Laboratories considers brightness, dispersion, leakage, contrast, and weight ratio, in addition to proportion, symmetry, and polish, when assigning a final cut grade.