Diamond Cuts
Diamond cut refers to how well a diamondβs facets interact with light. This diamond cut guide covers everything you need to know about diamond cuts, from how they impact sparkle to how theyβre graded.
What Are Diamond Cuts?
Diamond cut, one of the 4 Cs that determines diamond quality, refers to how effectively a diamond's facets interact with light. Many people confuse diamond cut with diamond shape (the external outline of a diamond, like round, oval, or pear), but cut is responsible for a diamondβs ability to transmit light and sparkle.
Precise artistry and craftsmanship are required to cut a diamond so that its proportions, symmetry, and polish deliver maximum light return and stunning shine. Simply put: the better the cut, the more a diamond will sparkle.
Why Is the Cut of a Diamond Important?
Cut is important when selecting a diamond because it directly determines a diamond's sparkle. An excellently cut diamond creates that classic, unmistakable brilliance you expect. On the other hand, a poorly cut diamond lacks light performance and appears dull.
Fair
Good quality cut which reflects some light while maximizing weight. While not as brilliant as a good cut, still a quality diamond.
How Are Diamonds Cut and Graded?
Diamonds are cut using specialized tools to facet and polish the stone, creating brilliance and symmetry. Because cut has such a direct impact on a diamondβs appearance, grading systems were developed to consistently evaluate cut quality.
These grading systems assess three key factors: appearance (brilliance, fire, scintillation), design (proportions), and craftsmanship (polish and symmetry). While the criteria are similar, most independent institutes use their own terminology to grade the overall cut of a diamond.
At aya, we also use specific scale language to help our customers understand the subtle differences in cut that affect price and quality. We base our scale on the cut specifications provided by the certifying gemological laboratory and grade diamonds from Super Ideal to Ideal, Very Good, Good, Fair, and Poor. This means that, for example, a GIA-certified diamond with an Excellent cut grade will be listed as a Super Ideal or Ideal diamond on the aya site.
- Gemological Institute of America (GIA) Cut Grading System: Excellent, Very Good, Good, Fair, Poor
- International Gemological Institute (IGI) Cut Grading System: Ideal, Excellent, Very Good, Good, Fair
- aya Cut Grading System: Super Ideal, Ideal, Very Good, Good, Fair, Poor
Anatomy of a Diamondβs Cut
To understand how cut is evaluated, it helps to first look at the physical parts of a diamond that make up its structure. Each part plays a role in how light enters, reflects, and exits the stone. When these characteristics are well balanced, the result is a diamond with exceptional brilliance and sparkle.
Table
The flat surface at the top of the diamond.
Crown
The top portion of a diamond, from the girdle to the table.
Girdle
The narrow rim around the widest part of a diamond, separating the crown from the pavilion. Also referred to as the setting edge, where a diamond is held when set in jewelry.
Pavilion
The lower portion of a diamond, from girdle to the culet.
Culet
The facet or point on the bottom of the diamond's pavilion.
Depth
The height of a gemstone, from the culet to the table. Determined as a percentage of the overall diameter of the gem.
Diamond Cut Quality Factors
Diamond Cut Grades
At aya, we use a detailed grading scale to help you understand differences in cut quality when choosing your diamond.
Super Ideal Cut Grade
A Super Ideal cut diamond's proportion, polish, and symmetry have all received a top grade (known by the GIA/IGI as Triple Excellent). These are the highest-quality stones and feature incredible, eye-catching sparkle.
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Ideal Cut Grade
An Ideal cut diamond's proportions must be within the ideal range, and polish and symmetry can each be one less than the highest grade. To the untrained eye, an Ideal diamond is just as beautiful as a Super Ideal diamond of the same color and clarity.
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Very Good Cut Grade
A Very Good cut diamond's proportions are just outside of the ideal range, and polish and symmetry can range from the highest grades to more moderate levels. These diamonds can present an incredible sparkle at a more accessible price point.
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Good Cut Grade
A Good cut diamond's proportions will be only slightly imperfect, allowing for plenty of light to reflect light. However, good-cut diamonds will not be as bright as higher-cut grades, as flawed ratios will leave more dark spaces in the stone, causing it to look duller. Depending on the balance of the other 4 Cs, good-cut diamonds will generally feature a more accessible price point.
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Fair Cut Grade
A Fair cut diamond has little light refraction compared to diamonds with higher cut grades. This is caused by gray areas surrounding the crown or areas of darkness or dullness within the table, girdle, or both. While Fair cut diamonds will be more accessible from a price point perspective, their lack of sparkle deters many customers from selecting them.
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Poor Cut Grade
Poor cut diamonds are generally not recommended as light spills from their pavilion, culet, or both. They will show a marked reduction in fire and scintillation from those with higher cut grades, as the dark areas are prominent and distracting. Please note that aya does not carry Poor-cut diamonds.
Different Types of Diamond Cuts
Now that we've discussed the different characteristics of cut grading, it's time to discuss how the facets of a diamond are cut. Note: it's important to remember that diamond cut and shape are not the same thing β but diamond shape informs how a diamond is cut.Β
Round Brilliant Cuts
By far the most popular and common shape of all, round brilliant cut diamonds are cut with 57 (without culet) to 58 (with culet) facets to return incredible brilliance, fire, and scintillation.Β
Fancy Cuts
Anything that isn't a round shape requires a fancy cut.Β
Modified Brilliant Cuts
A modified brilliant-cut diamond is a diamond altered from its traditional round shape. Pear, marquise, cushion, oval, and heart are all examples of modified brilliant cuts.Β
Step Cuts
Step-cut diamonds have rectangular facets. Compared to Brilliant cuts, step cuts can have less brilliance and fire due to the shape of their faceting. Emerald, asscher, and baguette diamonds are examples of step cuts.Β Β
Rose Cuts
Unlike step cuts or brilliant cuts, the lower halves of rose cuts are relatively flat. While this means they can be low profile, they don't feature the same brilliant sparkle. Any diamond shape can be rose cut, though round is the most common rose cut.
Vintage Cuts
Before modern technology, diamond cutting was a slow process β so the less material a cutter removed from the original rough diamond, the better. Because of this, old mine-cut and euro-cut diamonds typically have larger facets that result in less sparkle than a diamond of todayβs standard.
How Does Diamond Cut Impact Price?
Grades in all of the 4 Cs can impact price. Cut is no different β generally, the higher the cut grade, the higher the price. Finding the right diamond is a balancing act between your budget and the 4 Cs. For example, if sparkle is the most important to you, you may need to prioritize cut and sacrifice on carat, color, or clarity to stay within budget.