The fiery brilliance and sparkle that attracts us to a diamond is achieved and enhanced through its cut. As important as color and clarity, a diamond's cut largely influences its reflective nature and, thus, its overall quality and value. Light that enters into a diamond is reflected out as brilliance and fire. Therefore, diamonds with higher grades of cut will emit more sparkle than those with lesser cuts, resulting in a higher value placed on well-cut diamonds.

The amount of brilliance a diamond is able to flash is directly dependant on its width and depth. If a diamond is cut too shallow, the light entering the diamond will leak out its bottom, causing the diamond to lose its brilliance. If a diamond is cut too deep, the light will exit out its sides, causing the diamond to look dull.

Diamond Anatomy

Here are some other terms that you may encounter when learning about the cut of a diamond:

Diameter: The width of the diamond as measured from opposite sides of the girdle.

Depth: The height of a gemstone measured from the table to the culet. For round diamonds the depth should be 57% - 62%.

Table: Top and largest facet of the diamond. This should be 53%-62% for a round diamond.

Crown: The top portion of a diamond. Extends from edge of table to girdle.

Girdle: The narrow band around widest part of a diamond.

Pavilion: The bottom portion of a diamond, extending from the girdle to the culet.

Culet: The facet at the tip of the gemstone. The preferred culet is not visible with the unaided eye (graded "small" or "none").

Polish and Symmetry

Polish and symmetry are two important components of the cutting process. The polish grade describes the smoothness of the diamond's facets. If the polish is graded as poor, the surface of a facet can be dulled, creating a blurred or dulled sparkle. The symmetry grade refers to the alignment of the facets. If the symmetry is poor, light can be misdirected as it enters and exits the diamond.

Within a GIA grading report, polish and symmetry are graded as Excellent (EX), Very Good (VG), Good (G), Fair (F), or Poor (P). Avoid diamonds with polish and symmetry grades of fair or poor as these grades will have a significant effect on the brilliance and sparkle of the diamond.

Grading Cut

A diamond cutter spends years mastering his craft, learning how best to cut a rough diamond to achieve the maximum brilliance with the fewest imperfections and least loss of carat weight. The better the cut, the more valuable the diamond.

1. Ideal Cut: Mathematician Marcel Tolkowsky was the first to discover the exact angles to which a diamond must be cut in order to produce the maximum brilliance. Ideal cut diamonds reflect nearly all the light that enters the diamond. An exquisite and rare cut.
2. Very Good Cut: Close to an ideal cut with only slight variations in its measurements. It reflects nearly as much light as the ideal cut but for a lower price.
3. Good Cut: A well proportioned diamond that reflects back a good amount of light. Much less expensive than a very good cut. Represents roughly the top 25% of diamond quality based on cut.
4. Fair Cut: This is still considered a quality diamond; however, a fair cut will not be as brilliant as a good cut.
5. Poor Cut: These diamonds tend to lose most of the light out of the sides and bottom. DiamondsRight does not carry diamonds with cut grades of poor.