Diamond Cuts
Learn everything you need to know about diamond cuts, from how they sparkle to how they’re graded.
Expertise you can trust: All of our guides are meticulously researched and reviewed by our certified gemologists, content, editorial, and brand teams before publication to ensure industry-leading excellence and accuracy.
What Is Diamond Cut?
As one of the4 C's used to describe and determine diamond quality, cut references how well a diamond's facets interact with light. Though it's often confused with shape which refers to the external outline of a diamond (such as round, oval, or pear, cut is actually responsible for a diamond's 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. The better a diamond is cut, the more sparkly it will be.
Diamond Cut
Fair
Good quality cut which reflects some light while maximizing weight. While not as brilliant as a good cut, still a quality diamond.
Good
Premium quality cut to optimize the size without sacrificing quality or beauty. Reflects most light that enters.
Very Good
Superior quality cut that reflects nearly as much light as the ideal cut while at a substantially lower cost.
Ideal
Exquisite quality cut to create the optimal combination of brilliance and fire. Reflects nearly all light that enters the diamond.
Super Ideal
Cut to the most exacting standards. These diamonds have the most desirable dimensions and are proportioned to return the maximum possible light.
Why Is Cut Important?
Cut is a crucial factor to consider when selecting a diamond, as it is accountable for its sparkle. An excellently cut diamond will deliver the classic, unmistakable light show you expect from a diamond. A poorly cut diamond, on the other hand, will be much duller. As cut can significantly impact the appearance of a diamond and the light it emits, it's essential to understand what it is and how it's graded.
How Is Diamond Cut Graded?
The Gemological Institute of America (GIA) has extensively studied how light interacts with round brilliant cut diamonds to better understand the factors that contribute to their appearance and sparkle. The result of their studies was the GIA Cut Grading System, which standardizes and evaluates cut quality on appearance (brilliance, fire, scintillation), design (proportion), and craftsmanship (polish, symmetry). Their cut scale ranges from Excellent to Very Good, Good, Fair, and Poor.
Most independent institutes use their own language to rank the overall cut of a diamond. For example, the International Gemological Institute (IGI) adds an extra rank atop Excellent, rating their highest-quality diamonds as Ideal. At Purple Carats, we also use specific scale language to help our customers understand subtle cut differences affecting quality and price. We base our scale on the cut specifications the certifying gemological laboratory provides and rank 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 Purple Carats site.
Cut Characteristics
To best understand the cut grade of a diamond, it's important to understand the following characteristics that, when evaluated together, define a high-quality cut.
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.
Polish
Polish is the quality of a diamond's external surface condition as a result of the polishing process. Various features, such as pits or nicks, are considered in evaluating polish. It is graded on a scale ranging from Ideal or Excellent to Poor and is generally listed on a diamond certificate.
Symmetry
Symmetry is the exactness of a diamond's external shape and the even arrangement of its facets. Therefore, it can be divided into two categories: proportion-related (external) and facet-related (internal). It is also graded on a scale ranging from Ideal or Excellent to Poor and is generally listed on a diamond certificate.
Proportion
A diamond's proportion is measured by its crown and pavilion angles and the overall measurements of its facets. As facets are like tiny mirrors, their proportion can be a crucial contributor to the overall face-up appearance of a diamond. Proportion can also help professionals understand how well a diamond will produce sparkle.
Brilliance
Brilliance, sometimes referred to as brightness, is the internal and external white light that reflects from a diamond. Each time light enters a diamond, its internal facets send it off in different directions, depending on the angle and tilt of the facets. Masterfully cut diamonds demonstrate superb brilliance because they bounce light off multiple facet surfaces.
Fire
Fire is the scattering of white light into the colors of the rainbow. Diamonds are excellent at scattering light and displaying it as a spectrum of colors that glint sparks of red, orange, yellow, green, or blue.
Diamonds must be precisely cut for light to disperse in this manner. Imprecise, poorer cuts do not refract or scatter light as efficiently; instead, they allow the white light to escape before it can disperse a rainbow of sparkles.
Scintillation
Scintillation refers to the sparkle a diamond emits as you move it in the light: the facets split the white light into a spectrum of colors, creating sparks of light that appear to dance along the surface of the diamond. This is contrasted sharply against the darker, colored flashes that refract through the inner facets. The symmetry and balance between lighter and darker areas create the overall sparkle.
How Does Diamond Cut Impact Price?
Grades in all of the 4 C's can impact price. Cut is no different — generally, the higher the cut grade, the higher the price. Finding the right diamond is a balancing act between your budget and the 4 C's. 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.
Diamond Cut FAQ
What's the difference between diamond cut and diamond shape?
Diamond cut and diamond shape are not the same thing. Diamond shape refers to the external outline of a diamond (round, oval, or marquise, for example). Diamond cut refers to the precision and artistry used to craft a diamond's internal faceting and, therefore, brilliant sparkle. While both shape and cut are critical factors to consider when picking the perfect diamond, we suggest first deciding on the shape and then finding a diamond that balances the 4 C's of cut, color, carat, and clarity with your budget.
Is cut the most important of the 4 C's?
All of the 4 C's are important. Which will be the most important depends on your preferences. If a super sparkly diamond is imperative for you, cut will be the most important.
What is the most expensive diamond cut?
The most expensive diamond cut is generally the Excellent/Super Ideal cut, as it is the highest-quality cut grade. The ultimate price of the diamond will depend on the balance of all 4 C's.
What is the cheapest diamond cut?
The most affordable diamond cut is generally the Poor cut, as it is the lowest-quality cut grade. The ultimate price of the diamond will depend on the balance of all 4 C's. We don't recommend nor offer Poor-cut diamonds. We suggest at least a Very Good cut diamond to balance sparkle and budget.
Which diamond cut sparkles the most?
An Excellent/Super Ideal cut diamond will sparkle the most. A round brilliant diamond with an excellent cut grade will generally provide the most sparkle out of all shape/cut combinations.
What is the best diamond cut?
The best diamond cut is Excellent/Super Ideal. Determining the best diamond cut for you will depend on your budget and a balance of the other 4 C's.
What is used to cut a diamond?
As diamond is the hardest naturally occurring mineral on Earth, a laser or saw coated in diamond dust must be used to cut it.
What is the most popular diamond cut?
The most popular diamond cut ranges between Good - Excellent/Super Ideal.
What does a diamond look like before it's cut?
Before they are cut, diamonds feature rough forms that can vary in shape. While still quite beautiful, this cut does little to maximize the effects of light moving through the stone.
Learn More About Diamonds
Diamond Color Guide
Diamond Clarity Guide
Diamond Carat Guide
4 C's of Diamonds