The 4 Cs
colour
clarity
cut
carat weight
Diamond professionals use these four factors to describe and classify diamonds. When taken together, they help in evaluating the finished diamonds you buy. That's why they are often called value factors. This page considers cut.
You may wish to view the excellent tutorial on the Gemological Institute of America web site titled How to Buy A Diamond
cut
Standard Round Brilliant Cut
The three major parts of a polished diamond, top to bottom, are the crown, the girdle, and the pavilion. Some polished diamonds have a very tiny flat facet at the bottom of the pavilion, called the culet. The large flat facet on the top of a polished diamond is called the table.
The distance from the bottom of the girdle to the culet is the pavilion depth. A pavilion depth that’s too shallow or too deep will allow light to escape from the side of the stone, or leak out of the bottom. A well-cut diamond will direct more light through the crown.
Cutting a diamond to produce the maximum return of light depends on the interrelationship between three critical proportions – table size, crown angle and pavilion depth. These can be combined in many ways to yield equally bright round brilliant cut diamonds.
| Available Cuts | |||||||||
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| Round | Asscher | Cushion | Emerald | Heart | Marquise | Oval | Pear | Princess | Radiant |
Emerald Cut Diamond Cut Guide (specifications for Ideal to Very Fine Cut)
| Select Emerald Cut Diamonds within these ranges | |
| Total depth % | 65% - 75% |
| Table % | 65% - 75% |
| Girdle Thickness | Very Thin - Thick |
| Culet | None - Medium |
| Polish | Excellent - Good |
| Symmetry | Excellent - Good |
| Florescence | None - Faint |
| Length to Width ratio | 1.35 - 1.65 to 1 |
Marquise Cut Diamond Cut Guide (specifications for Ideal to Very Fine Cut)
| Select Marquise Cut Diamonds within these ranges | |
| Total depth % | 62% - 68% |
| Table % | 50% - 62% |
| Girdle Thickness | Very Thin - Thick |
| Culet | None - Medium |
| Polish | Excellent - Good |
| Symmetry | Excellent - Good |
| Florescence | None - Faint |
| Length to Width ratio | 1.7 - 2.2 to 1 |
Pear Shape Cut Diamond Cut Guide (specifications for Ideal to Very Fine Cut)
| Select Pear Shape Cut Diamonds within these ranges | |
| Total depth % | 62% - 68% |
| Table % | 50% - 62% |
| Girdle Thickness | Very Thin - Thick |
| Culet | None - Medium |
| Polish | Excellent - Good |
| Symmetry | Excellent - Good |
| Florescence | None - Faint |
| Length to Width ratio | 1.5 - 1.75 to 1 |
Princess Cut Diamond Cut Guide (specifications for Ideal to Very Fine Cut)
| Select Princess Cut Diamonds within these ranges | |
| Total depth % | 65% - 80% |
| Table % | 65% - 80% |
| Girdle Thickness | Very Thin - Thick |
| Culet | None - Medium |
| Polish | Excellent - Good |
| Symmetry | Excellent - Good |
| Florescence | None - Faint |
| Length to Width ratio | 1.0 - 1.4 to 1 |
