DIAMOND PROPORTIONS
THE IDEAL CUT
When a round, brilliant diamond has been cut to "Ideal" proportions by a master cutter, it has a splendor to behold.
The Ideal Cut Diamond describes a round brilliant diamond that has been cut to exact mathematically proven proportions. Its symmetry, with 58 exactly placed facets, produce the ultimate in lustre and beauty.
When a diamond is cut to ideal proportions, all of the light entering from any direction is totally reflected through the top and is dispersed into a display of sparking flashes and rainbow colours.
THE PREMIUM CUT
A Premium Cut diamond demonstrates subtle variations from the Ideal Cut. Although dimensional differences affect a diamond's reflection of light, a Premium Cut still achieve a harmonius balance between its proportions and the display of brilliance
Preferred Proportions for Round Diamonds
| |
Ideal Proportions |
Acceptable |
| Depth Percentage: |
60.2% - 62.7% |
57.0% - 64.0% |
| Table Percentage: |
53% - 57.0% |
53.0% - 64.0% |
| Polish: |
Very Good to excellent |
Good to Very Good |
| Symmetry: |
Very Good to excellent |
Good to Very Good |
| Girdle: |
Thin to medium |
Thin to Thick |
| Culet: |
None to very small |
None to medium |
Preferred Proportions for Oval, Pear, Marquise, and Heart-Shaped Diamonds
| Depth Percentage: |
58.9% - 65.4% |
| Table Percentage: |
53% - 64% |
| Polish: |
Good to excellent |
| Symmetry: |
Good to excellent |
| Girdle: |
Thin to thick |
Preferred Proportions for Emerald and Radiant Cut Diamonds
| Depth Percentage: |
59.9% - 69.0% |
| Table Percentage: |
59% - 69% |
| Polish: |
Good to excellent |
| Symmetry: |
Good to excellent |
| Girdle: |
Thin to thick |
Preferred Proportions for Princess Cut Diamonds
| Depth Percentage: |
64.0% - 75.0% |
| Table Percentage: |
59% - 72% |
| Polish: |
Good to excellent |
| Symmetry: |
Good to excellent |
| Girdle: |
Thin to thick |
|
