The GIA study noted during the observational survey that factors other than proportions played a role in diamond beauty. This table attempts to simplify those observeations.
| Factor | No effect | Slight effect | Noticeable reduction |
Color | D decrease in apparent brightness as saturation increases Z |
Clarity | IF to SI1 | Grade determining Clouds in SI2 | Grade determining Clouds in I1 > |
Symmetry | Excellent VG Good | Fair > reduced brightness > Poor |
Polish | Excellent VG Good | Fair> reduced brightness and fire > Poor |
Girdle | No effect on apparent brightness and fire from girdle condition |
Fluoro | No effect on apparent brightness and fire |
Factors that showed discernable effects on brightness and fire that were noted by observers during the GIA survey study.