Ideal (Cut)
Highest cut grade, issued primarily by AGS. Proportions optimised for maximum light return, fire, and brilliance.
Ideal (Cut): Highest cut grade, issued primarily by AGS. Proportions optimised for maximum light return, fire, and brilliance.
Ideal is AGS's top cut grade; the closest GIA equivalent is Excellent. Both signify proportions that return light efficiently to the viewer. In round brilliants, Ideal cut is more important to visible performance than any other C. A well-cut SI1 will outshine a poorly-cut VS1 every time.
Standards bodies: AGS
Frequently asked questions
Is Ideal cut the same as Excellent?
AGS Ideal and GIA Excellent are close but not identical. AGS uses a performance-based grading system (how much light the stone returns); GIA uses proportion-based grading. In practice, both are top-tier and visually excellent.
Does Ideal cut matter for fancy shapes?
GIA does not issue a full cut grade for fancy shapes (only round). For fancy shapes, evaluate Polish, Symmetry, and the clarity plot directly. AGS does grade some fancy shapes.
Related terms
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