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Jewelry Basics

The Four Cs of a Diamond: Diamond Cut

Of the 4Cs, a diamond's cut has the greatest influence on how a diamond reflects, making it arguably the most important C. A diamond’s cut refers to the balance of proportion, symmetry and polish achieved by the diamond cutter. How well the diamond is cut directly correlates to the diamond’s overall beauty. When a diamond has been correctly cut, its ability to reflect and refract light is enhanced immensely. Modern diamond cutters have come to understand the way light moves through diamond crystals, and have established a specific set of proportions and angles that are known to harness the diamond’s internal brilliance and to show it in its best light. When grading a diamond, laboratories will evaluate the diamond for its brilliance, fire and scintillation.


● Brilliance, or brightness, is the white light that is reflected back to one’s eye from the diamond.

● Fire, otherwise known as dispersion, is the rainbow of colors reflected back to one’s eye from the diamond.

● Scintillation, or sparkle, is the play of light seen when the diamond is in motion. This is demonstrated by sparkling on the diamond’s surface.

When considering the cut of a diamond, it helps to be familiar with its characteristics. Here is an overview of the anatomy of a diamond and the measurements that play a key role in determining its cut.

● The table is the flat surface at the top of a diamond.

● The crown is the top portion of the diamond, from the girdle to the table.

● The girdle is the narrow rim around the widest part of the diamond, separating the crown from the pavilion. This is also referred to as the setting edge, where a diamond is held when set in jewelry.

● The pavilion is the lower portion of the diamond, from the girdle to the culet.

● The culet is the facet or point at the bottom of a diamond’s pavilion.

● A diamond’s depth refers to the height of the stone, from the culet to the table.


That a well-cut diamond will often appear larger than a poorly-cut diamond of the same carat weight, and appear to have enhanced color and clarity?

GIA, one of the most respected laboratories for grading natural diamonds, uses the following system to grade round-cut diamonds:

Grade Description
Super Ideal

Cut to the most exacting standards. These diamonds have the most desirable dimensions and are proportioned to return the maximum possible light.


Exquisite quality cut to create the optimal combination of brilliance and fire. Reflects nearly all light that enters the diamond. Top 3% of diamond quality based on cut.

Very Good

Superior quality cut that reflects nearly as much light as the ideal cut while at a substantially lower cost.


Premium quality cut to optimize the size without sacrificing quality or beauty. Reflects most light that enters.


Adequate quality cut that reflects some light while maximizing weight. While not as brilliant as a good cut, still a quality diamond.


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