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Diamond Cut

One of the most defining characteristics of a diamond is its cut. Diamond cut is the summary of a diamond's proportions evaluated using the attributes of brilliance, fire, and scintillation. While high grades of color, clarity, and carat weight affect a diamond, it's the cut that determines the symmetry of the stone's facets, its overall proportions, and its ability to reflect light. An expertly-cut diamond will achieve high levels of brilliance, sparkle, and durability. Even if a diamond is graded well in other areas, a poor cut can result in a dull, muted effect.

Parts of a Diamond

A diamond is comprised of five main parts that affect its shape and radiance. Knowing these terms will help you understand the important components to consider when selecting a diamond.

Table & Table Percentage

Table & Table Percentage

The largest facet of the diamond, a table is the flat surface on the top of the stone, resembling a 'table'.

A diamond's table is the largest facet of the stone, comprising the flat surface on the top. The table percentage is the ratio of the width of the diamond's top facet in relation to the width of the entire stone. The right ratio results in a large amount of fire and brilliance. To learn about the ideal table percentage for each diamond shape, visit our Diamond Shape page.

Crown

This is the top portion of the diamond, located above the girdle and extending below the table.

A diamond's crown extends from the top of the stone (the 'table') down to the girdle (the widest point of the diamond). Crowns can be comprised of step cut facets or brilliant cut facets.

Crown
Girdle

Girdle

Forming the outer edge of the diamond, this is where the crown and the pavilion meet and is the widest part of a diamond.

This is the portion of the diamond between the crown and the pavilion, essentially spanning the width of the stone from side to side. The measurement of the girdle represents the perimeter of the diamond. A diamond's girdle can be rough, polished, or faceted, and does not typically affect the quality or appearance of the stone.

Learn more about Diamond Girdle  

Pavilion

Located at the bottom of the diamond, the pavilion bridges the girdle and the culet and form at the bottom (culet).

Located between the girdle and the culet (point), the pavilion is integral to the stone's light reflecting properties. A properly cut pavilion will allow the maximum amount of light to reflect from the surface of the stone. An excessively deep or shallow diamond can cause light to escape out of the bottom and sides, reducing its sparkle.

Pavilion
Culet

Culet

The smallest facet of a diamond, the culet is located at the very bottom of the stone.

The smallest facet of a diamond, the culet is located at the very bottom of the stone. If the diamond ends in a point, the diamond grading report will show a value of 'None' for the culet designation. This small facet was originally intended to protect the diamond's pavilion, although today's settings are usually strong enough to render it unnecessary.

Learn more about Diamond Culet  

A Diamond's Depth

A diamond's depth can be determined by measuring the entire stone's height from the table to the culet and is described in millimeters. The depth percentage measures the ratio of the stone's depth (from the table to the culet) to the diamond's total diameter. To learn about the ideal depth percentage for each diamond shape, visit our Diamond Shape page.

A Diamond's Depth | Brilliance.com

Light's Effect on a Diamond

There are many factors that affect a diamond’s brilliance, the most important of which is its ability to reflect light. As a diamond passes through a light source, tiny flashes will be visible within the stone.

Reflection

When light enters the surface of a diamond, a portion of it is reflected back out of the table (top).

Reflection

Refraction

The remaining rays of light travel into the center of the diamond and bounce off its internal walls.

Refraction

Dispersion

As light exits the diamond, dispersion causes the white light to be separated into multiple colors.

Dispersion

Shallow Cut

Although a shallow cut diamond will create the illusion of a larger stone, it allows light to escape out the sides instead of reflecting off the top, creating a lack of brilliance and sparkle.

Shallow Cut

Ideal Cut

If you're seeking a high quality diamond that beautifully reflects light, this is the cut for you. This premier cut style is well-proportioned and carefully angled to achieve a luminous appearance.

Ideal Cut

Deep Cut

This type of cut poorly reflects light, resulting in a dull, muted appearance. A diamond that is cut too deep will look smaller compared to diamonds in the same carat size range with ideal depths.

Deep Cut

Diamond Faceting

With modern diamond-cutting techniques, there are two common methods of cutting facets, each with its own unique, light-reflecting properties:

Step Cut Faceting

Step Cut Faceting

In this approach, the facets are elongated and placed in rows to simulate a mirrored staircase.

Brilliant Cut Faceting

This technique creates triangular-shaped facets that face outwards from the center of the diamond.

Diamond Polish, Symmetry & Cut Grade

A diamond's polish and symmetry are critical to the quality of its cut. For maximum brilliance, every facet of a diamond should be professionally polished after the cutting process. A high quality polish will leave little to no scratches and marks, while a poor polish can result in imperfections on the surface of the diamond, which can lower its value.

A symmetrical diamond will have well-balanced, properly aligned facets, resulting in a high level of fire and brilliance. If the facets are not symmetrical or not optimally shaped, they'll display less sparkle.

A gemologist assigns a cut grade as a means of measuring a diamond's proportions, craftsmanship, quality of polish, and light reflecting properties.

A diamond with a high quality cut grade will exude a large amount of brilliance and fire. A diamond's ratings for symmetry, polish, and cut grade may vary based on which Gemological Laboratory is evaluating it, as each agency uses a different scale. To learn more, visit our Diamond Certification page.


Not all certification labs offer a “Cut” on their certificates especially when it comes to fancy shaped diamonds (non-round cuts). Understanding that this is a crucial factor when purchasing a diamond, Brilliance gives its own rating on a diamond called a “Diamond Make or Cut”. Combining all the different factors that are important in a diamond cut, “Make” is a term used to describe the overall appearance of a diamond and is based on a combined analysis of its shape, cut, proportions, polish, symmetry, and light reflecting properties. The “Make” of a diamond directly impacts its brilliance and beauty; if a diamond is designed, cut, and finished properly, it will have a much more desirable appearance, even when compared to diamonds of higher color and clarity grades. Brilliance gemologists use this term to provide our customers with a general assessment of cut to simplify shopping for the perfect loose diamond.

We use the following designations to rate the 'Make' or Cut of our diamonds:

Super Ideal Make: Our highest quality cut, this Make will reflect the maximum amount of light, exhibiting unrivaled brilliance and fire. 'Super Ideal' Make diamonds are extremely rare; only 5% of our loose diamond assortment receives this grade.

Ideal Make: This indicates a superior level of craftsmanship, emitting the most brilliance and light. Consumers seeking premium cuts prefer 'Ideal' Make diamonds.

Excellent Make: Cut to a high-quality polish and symmetry, this diamond Make will reflect all light as brilliance and fire.

Very Good Make: This grade of diamond reflects nearly all light that enters. Less expensive than an 'Excellent' Make, it still displays a good amount of brilliance and sparkle.

Good Make: An economical choice for the diamond shopper on a limited budget, a 'Good' Make reflects most light that enters it, offering beauty at an attractive value.


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