Analysis & Grading

AGS Ideal® Report by GIA


Now through September 1, 2024, the 50% rejection fee will be waived for diamonds that do not qualify. Primary and secondary service fees still apply regardless of AGS Ideal eligibility.

A Supplemental Report for Premium Diamonds

The AGS Ideal® Report complements a GIA diamond grading report to capture a diamond’s beauty holistically. This report measures light performance, including brightness, fire, and contrast, from center to edge. 

Only a small percentage of premium diamonds qualify to receive this supplemental report, including eligible colorless (D-to-Z) natural and laboratory-grown round brilliant and fancy shape diamonds. The AGS Ideal® Report is a digital report with a printed version available for an additional charge.

What the AGS Ideal® Report Measures

AGS light performance measures and assesses the performance, proportions, and finish, including symmetry and polish of a diamond. This assessment includes:

  • Brightness: The effect of all the diamond's internal and external reflections of white light.  
  • Fire: A diamond’s display of dispersion, the optical phenomenon of white light separating into spectral or rainbow colors. 
  • Contrast: The relative size, arrangement, and contrast of bright and dark areas when viewed face-up. 

While a GIA grading report provides information on the diamond’s 4Cs, the AGS Ideal® Report provides additional context to premium diamonds to help reveal their full beauty.

AGS Ideal® Zero Rating

In a stone with an AGS light performance grade of AGS Ideal® zero, the diamond's brightness, fire, and contrast must be given a rating of zero. That means:

  • The diamond remains bright from edge to center with a high amount of brightness, while minimizing the amount of light leakage.
  • The diamond has high fire potential from edge to center.
  • There is an equal amount of contrast scattered across the entire stone.

Note that it is possible to have an AGS Ideal® zero diamond that will not qualify for the AGS Ideal® Report. For example:

  • Diamonds with high degrees of optical precision do not always translate into high light performance. 
  • Painting and digging out may not affect the symmetry grade, but it can affect the light performance. Therefore, it is possible to receive an Excellent symmetry grade but not an AGS Ideal 0 Light Performance grade. 


The ASET® Map is the key to understanding how the diamond deals with light, and ultimately, how beautifully the diamond is performing. It displays optical symmetry, physical symmetry, and optical efficiency to show the craftsmanship of the diamond’s cut. It is created by the Angular Spectrum Evaluation Tool (ASET®) which uses software to trace individual rays of light.

The ASET® Map features three colors that give you a unique thumbprint of the diamond, documenting its light performance and beauty:

  • Red indicates the brightest areas of the diamond that attract the brightest light from above. 
  • Green also indicates light return, but from an indirect source which is not as bright. 
  • Blue indicates a contrast pattern of dark reflections. 
The ASET® Map is optional when ordering the AGS Ideal® Report. 

Qualifying Diamonds for the AGS Ideal®

This report is only available for eligible colorless (D-to-Z) natural and laboratory-grown diamonds with specific facet arrangements listed below.

  • Round brilliant: Excellent grading for polish, symmetry, and cut.
  • Fancy shapes: Excellent grading for polish and symmetry for round modified, cushion, cut-cornered rectangle, oval, cut-cornered square, emerald, modified triangle, square emerald, decagon, rectangle, and square. 

Note that even if a diamond has one of the above shape outlines, only specific facet arrangements will qualify. 

How to Request an AGS Ideal® Report

An AGS Ideal® Report with or without an ASET® Map is a supplemental service and must be requested while your stones are at a GIA laboratory for services:

  • If your diamond already has a GIA report, you may resubmit the diamond for an update grading service and request the supplemental AGS Ideal® Report with or without an ASET® Map at that time.  
  • The diamond must be submitted as a loose stone. No mounted diamonds will be accepted.  

AGS Ideal® Support Tools

Need more support? Contact a GIA representative.