What Is Diamond Cut?
Diamond cut refers to how well a diamond's facets interact with light, affecting its brilliance, fire, and sparkle. A diamond's proportions, symmetry, and polish all play a role in how light moves through the stone and reflects back to your eye.
Diamond cut is often confused with diamond shape, but they're not the same thing. Shape refers to a diamond's outline, such as round, oval, or pear, while cut describes the arrangement and precision of its facets.
A well-cut diamond reflects light effectively, creating the brilliance and sparkle diamonds are known for.
Why Does the Cut of a Diamond Matter?
Diamond cut is important because it has a direct impact on how much a diamond sparkles. When a diamond is cut with the right proportions and precise faceting, more light returns through its surface, creating a bright, lively appearance.
A poorly cut diamond, on the other hand, can allow light to escape through its bottom or sides, making it appear darker or less brilliant.
Diamond Cut Chart
Diamonds are cut and polished using specialized tools that shape the rough stone into precisely arranged facets. The angles, proportions, and symmetry of these facets determine how effectively the diamond interacts with light.
To evaluate cut quality, gemological laboratories 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.
Grading System | Diamond Cut Scale |
|---|---|
GIA | Excellent, Very Good, Good, Fair, Poor |
IGI | Ideal, Excellent, Very Good, Good, Fair |
Brilliant Earth | Super Ideal, Ideal, Very Good, Good, Fair, Poor |
At Brilliant Earth, 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 Brilliant Earth site.
Anatomy of a Diamond’s 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
Crown
Girdle
Pavilion
Culet
Depth
Table
The flat surface at the top of the diamond.
Diamond Cut Quality Grading Factors
Diamond cut quality is evaluated through three main factors: appearance, design, and craftsmanship. Together, they help determine how effectively a diamond reflects light and how its proportions and facets contribute to its overall appearance.
Appearance
A diamond's appearance is evaluated through three optical effects: brilliance, fire, and scintillation. Each contributes something different to the way a diamond sparkles.
- Brilliance: The white light reflected from a diamond, both internally and externally. Well-cut diamonds reflect more light back toward the viewer, creating a bright appearance.
- Fire: The flashes of rainbow-colored light produced when a diamond disperses white light into its individual colors. Precise faceting helps create these colorful flashes.
- Scintillation: The sparkle and contrasting patterns of light and dark seen as a diamond, the light source, or the viewer moves. A diamond's facet arrangement and symmetry influence this effect.
Design
A diamond's design focuses on its proportions and how they affect its appearance and light performance.
- Proportions: The relationship between a diamond's measurements, including its crown and pavilion angles, depth, and facet dimensions. These proportions influence how light travels through the stone and how much returns to the viewer.
Craftsmanship
Craftsmanship refers to the precision and quality of a diamond's finishing. Two important factors are polish and symmetry.
- Polish: The condition and smoothness of a diamond's finished facet surfaces. Features such as pits and nicks can affect the polish grade, which is typically included on a diamond grading report.
- Symmetry: How precisely a diamond's facets are arranged and how evenly its shape is formed. Good symmetry helps create balanced patterns of light and dark throughout the stone.
Diamond Cut Quality Grades
Diamond cut grades describe how well a diamond has been proportioned and finished, with higher grades generally producing stronger light performance.
At Brilliant Earth, we use six cut grades, ranging from Super Ideal to Poor. Each grade reflects differences in proportions, polish, symmetry, and overall appearance.
Super Ideal Cut
Super Ideal is our highest diamond cut grade. These diamonds have top grades for proportions, polish, and symmetry, commonly described as Triple Excellent, and are cut to deliver exceptional brilliance, fire, and sparkle.
Super Ideal diamonds represent the highest level of cut quality in our grading system.
Ideal Cut
Ideal cut diamonds have proportions within the ideal range, while polish and symmetry may each be one grade below the highest level.
They offer excellent brilliance and sparkle, and to the untrained eye, an Ideal diamond can look just as beautiful as a Super Ideal diamond with the same color and clarity.
Very Good Cut
Very Good cut diamonds have proportions just outside the ideal range, with polish and symmetry grades that may vary.
These diamonds can still produce impressive brilliance and sparkle, often at a more accessible price than higher cut grades. For those looking to balance appearance and budget, Very Good is a practical starting point.
Good Cut
Good cut diamonds have slightly imperfect proportions that affect how efficiently they reflect light. Although they can still produce noticeable brilliance, some light may escape, creating darker areas within the stone.
Good cut diamonds are generally more affordable than higher cut grades, depending on their other characteristics.
Fair Cut
Fair cut diamonds reflect less light than diamonds with higher cut grades, resulting in a more subdued appearance. Gray or dark areas may be visible around the crown, table, or girdle, reducing the stone's overall brilliance.
While these diamonds typically come at a lower price, their reduced sparkle makes them a less popular choice.
Poor Cut Grade
Poor cut diamonds have proportions that allow a significant amount of light to escape through the pavilion, culet, or both. As a result, they tend to show noticeable dark areas and decreased brilliance, fire, and scintillation.
*Brilliant Earth does not carry Poor cut diamonds.
Different Types of Diamond Cuts
In addition to quality grades, diamond cuts can also be categorized by how their facets are arranged. While cut quality describes how effectively a diamond interacts with light, the cutting style helps determine the type of sparkle it produces.
Diamond shape influences the cutting style, but the two terms aren't interchangeable. The main categories include round brilliant cuts and fancy cuts, with several different faceting styles within the latter.
Round Brilliant Cuts
Round brilliant is the most popular diamond cut. It features 57 or 58 facets, depending on whether the diamond has a culet, arranged to maximize brilliance, fire, and scintillation.
The round brilliant cut is particularly known for its ability to reflect light and produce strong sparkle.
Fancy Cuts
Fancy cuts include diamonds that aren't round brilliant. These cuts come in a variety of shapes and faceting styles, each creating a different appearance.
Modified Brilliant Cuts
Modified brilliant cuts use a brilliant-style facet arrangement adapted to non-round diamond shapes. They offer much of the sparkle associated with round brilliant diamonds while creating a different silhouette.
Common examples include:
Step Cuts
Step-cut diamonds feature long, rectangular facets arranged in parallel rows. Rather than producing the same intense sparkle as brilliant cuts, they create a distinctive hall-of-mirrors effect with broader flashes of light.
Common examples include:
Rose Cuts
Rose-cut diamonds have a relatively flat base and a faceted upper surface, giving them a low-profile appearance. Their faceting produces a softer sparkle than traditional brilliant cuts.
Rose cuts can be used on several diamond shapes, although round is the most common.
Vintage Cuts
Vintage diamond cuts reflect the cutting techniques used before modern technology. Early diamond cutters often worked to preserve more of the original rough stone, resulting in larger facets and different proportions than modern brilliant cuts.
Old mine and old European cuts are two well-known examples. Compared to modern brilliant diamonds, they typically produce broader, less intense flashes of light.
FAQ
What are the best diamond cuts?
Super Ideal is the highest cut grade in Brilliant Earth's grading system, while Excellent is the highest grade on GIA's scale. Both represent exceptional cut quality. However, the best choice depends on your budget and how you prioritize the other 4 Cs. Our jewelry specialists typically recommend Very Good cut or better.
What diamond cut sparkles the most?
A round brilliant diamond with an Excellent or Super Ideal cut grade generally produces the most sparkle. Its precise facet arrangement is designed to maximize brilliance, fire, and scintillation.
What does diamond cut mean?
Diamond cut refers to how well a diamond's facets interact with light. Its proportions, symmetry, and polish influence how much light returns to the viewer, affecting the diamond's brilliance, fire, and sparkle.
What are the different diamond cuts?
Diamond cuts include round brilliant and several types of fancy cuts. Common fancy cutting styles include modified brilliant cuts, such as oval and pear, step cuts, such as emerald and Asscher, rose cuts, and vintage cuts, such as old mine and old European. Each style has a different facet arrangement that influences its appearance and sparkle.
What is the most expensive cut of diamond?
Excellent or Super Ideal cuts are generally the most expensive cut grades because they represent the highest levels of cut quality. However, a diamond's final price also depends on its carat weight, color, and clarity.
Which diamond cut looks the biggest?
A well-cut diamond reflects light efficiently, creating brightness and sparkle that draw the eye outward and make the diamond look bigger, brighter, and more open.
For maximum impact, look for diamonds graded Ideal or Super Ideal in cut quality. Even at a lower carat weight, prioritizing cut can dramatically improve how big a diamond appears.
Which diamond cut sparkles the least?
Poor cut diamonds sparkle the least. Their proportions allow a significant amount of light to escape through the pavilion, the culet, or both, resulting in noticeable dark areas and decreased brilliance, fire, and scintillation.
What is the most popular diamond cut?
Round brilliant is the most popular diamond cutting style. When comparing cut quality grades, diamonds from Good through Excellent or Super Ideal are commonly selected, depending on budget and personal preferences.
What is the least expensive diamond cut?
Poor cut is generally the least expensive diamond cut grade because it has the lowest light performance. Brilliant Earth doesn't offer Poor cut diamonds, and we recommend starting with Very Good cut or higher for a balance of sparkle and budget.
What's the difference between diamond cut and diamond shape?
Diamond cut describes how a diamond's facets are arranged and how effectively they reflect light, while diamond shape refers to its outline, such as round, oval, or pear. Both influence a diamond's appearance. We recommend choosing a shape you like first, then comparing cut quality and the other 4 Cs within your budget.
Is cut the most important of the 4 Cs?
Cut is often considered the most important of the 4 Cs because it directly affects a diamond's brilliance and sparkle. However, the right priority depends on your preferences. If size, color, or clarity matters more to you, those characteristics may take precedence.
What does a diamond look like before it's cut?
Before cutting, a diamond is a rough stone with an irregular or naturally formed shape rather than the polished facets seen in finished jewelry. While rough diamonds have their own appearance, cutting and polishing bring out the brilliance and sparkle associated with finished diamonds.
How does diamond cut impact price?
Diamond cut affects price because higher cut grades generally require more precise craftsmanship and produce stronger light performance. As cut quality increases, so does the price, although the other 4 Cs also influence a diamond's overall cost.
Choosing a diamond often means balancing these characteristics against your budget. If sparkle matters most to you, prioritizing cut quality may mean being more flexible with carat weight, color, or clarity.
A well-cut diamond doesn't need the highest grades in every category to look beautiful. The right balance comes down to which characteristics matter most to you.
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