Proportions charts for Pear, Heart, Oval & Marquise Cut
| Ideal Cut | Premium Cut | International Fine Trade Cut | US domestic Average Cut | Below Average Cut | ||||
| Cut classes | Class 1A | Class 1B | Class 2A | Class 2B | Class 3A | Class 3B | Class 4A | Class 4B |
| Table, % | 57-60 | 60.1-61.5 56.9-54 |
61.6-62 53.9-53 |
62.1-64.0 52.9-52 |
64.1-67.0 51.9-51.0 |
67.1-70.0 50.9-50 |
70.1-72.0 49.9-49 |
>72.0 <49.0 |
| Crown height, % | 13-14.5 | 12.9-12.5 14.6-15 |
12.4-12 15.1-15.6 |
11.9-11.1 15.7-16.5 |
11.0-9.7 16.6-17.3 |
9.6-8.7 17.4-18.4 |
8.6-7.8 18.5-19.5 |
< 7.8 > 19.5 |
| Girdle Thikness, % Word description and percentages |
Thin to Medium or Medium to Thick 1% to 3.0% or 1.7% to 5.5% | Thin to Thick 1% to 5.5% > more variance allowed | Very thin to Very thick 0.4% to 7.0% | Extremely thin to Extremely thick 0% to > 7.0% | ||||
| Total Depth, % Determined by factors already considered above |
59.0-63.0 | 63.1-65.4 58.9-58.0 |
65.5-68.5 57.9-56.0 |
68.6-71.0 55.9-46.0 |
71.1-73.0 45.9-43.0 |
> 73.0 < 43.0 |
||
| Length/Width ratio Trade Preferences. A matter of personal taste and choice. |
Pear 1.50-1.75 Marquise 1.75-2.25 Heart 0.98-1.02 Oval 1.33-1.66 |
1.26-1.99 1.51-2.49 1.24-0.91 1.26-1.74 |
> Class 3 < Class 3 |
|||||
| Polish/Symmetry Not a primary determining factor |
Excellent to Good | Good or Fair | Poor | |||||
Jason Withers
group on Facebook