In 2006 GIA introduced a new diamond cut grading system. We believe it favors diamond cutters who chase yield, they use a proportion based system which is technically in breach of my HCA patent, but with considerably deeper proportion ranges. In the same year AGS changed their flawed proportion based system. The AGS light performance system is based on the ASET scope, a multi colored version of the Ideal-Scope which I made for them under license and sell here for $50.

The progression of red reflection scopes that AGS are developing for their new cut grading system. DiamCalc which is also available for purchase on this site.

Many old AGS 0 cut grade diamonds are no longer AGS 0 under the light performance grade based system! And there are more GIA Excellent cut graded diamonds that fail AGS, Ideal-scope and ASET testing than pass!

Round diamonds that look good through the ideal-scope and fancy shapes that look good in the ASET scope will stand out and be far easier to sell