Some diamonds draw your attention instantly. Others, despite having similar specifications, simply do not create the same impression. The difference is often not carat weight, colour, or clarity. It is cut.
Cut grade determines how effectively a diamond handles light, influencing its brilliance, fire, and overall visual presence. It is also one of the most misunderstood aspects of diamond selection. Many people spend time comparing carat weights or clarity grades while overlooking the factor that has the greatest impact on what they actually see.
For anyone buying a lab grown diamond, understanding cut grade is essential. A beautifully cut diamond can appear brighter, more dynamic, and more captivating than a larger diamond with a lower grade. At Keemti, we believe confidence comes from knowing what makes a diamond exceptional.
Here is what diamond cut grade really means, why it matters, and why Excellent remains the benchmark worth choosing.
Cut Is Not the Same as Shape
This is where most confusion starts. When someone says they want a round diamond or an oval solitaire, they are describing the shape. The diamond cut grade is something different entirely. It refers to how precisely the diamond has been faceted, proportioned, and polished so that light travels through it the way it is supposed to.
A round brilliant diamond can be round in shape and still receive a poor cut grade if its angles and proportions are off. Shape tells you what the diamond looks like as an outline. Cut grade tells you how it performs as a piece of light.
Diamond Cut Grades Explained: Excellent, Very Good, Good, Fair and Poor
The GIA cut grading system evaluates round brilliant diamonds on a five point scale: Excellent, Very Good, Good, Fair, and Poor. The grade reflects how effectively a diamond interacts with light, influencing its brilliance, fire, and overall sparkle.
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Cut Grade
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What It Means
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How It Appears
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Excellent
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The highest cut grade, where the diamond reflects maximum light through its facets.
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Shows exceptional brilliance, fire, and sparkle.
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Very Good
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A well balanced cut with strong light return, though slightly less precise than Excellent.
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Appears highly brilliant with differences that are often difficult to notice.
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Good
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A cut that allows a reasonable amount of light reflection, but some light may escape.
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Offers good sparkle but may appear less lively compared to higher grades.
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Fair
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A cut where significant light leakage affects the diamond’s performance.
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May look less bright and appear flatter under different lighting conditions.
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Poor
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A cut with noticeable light loss due to proportions that do not maximise brilliance.
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Struggles to display the desired sparkle and brilliance.
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For someone choosing a lab grown diamond, the difference between Excellent and Very Good cut grades may seem subtle on paper. However, when viewed under different lighting conditions, these details influence how the diamond reflects light and catches the eye. A well cut diamond allows its natural brilliance to become the centre of attention.
Why Cut Matters More Than Carat
When choosing a diamond, carat weight is often the first detail people notice, but cut determines how beautifully the diamond interacts with light. A larger diamond with an average cut may appear less brilliant than a smaller diamond with an excellent cut.
The right cut enhances sparkle, symmetry, and light performance, allowing the diamond to reveal its true beauty. At Keemti, we focus on this balance of craftsmanship and brilliance, ensuring every diamond is chosen for how it shines, not just its size.
Understanding the Triple Excellent Benchmark
When you read a grading certificate for a lab grown diamond, you will often see three separate grades listed: Cut, Polish, and Symmetry. When all three are graded Excellent, the diamond is referred to as Triple Excellent, or 3EX. This is a benchmark widely recognised across leading grading laboratories, including IGI and SGL, and it is the standard we hold our Keemti diamonds to.
A diamond can achieve Very Good symmetry alongside an Excellent cut, and it will still be beautiful. However, Triple Excellent indicates that the diamond's cut, polish, and symmetry have all been executed with exceptional precision.
For types of lab grown diamonds certified by IGI or SGL, this level of grading is both achievable and increasingly sought after because it helps ensure the diamond delivers its full visual potential. When evaluating a diamond, it is always worth checking whether all three grades align at the highest level.
Why Excellent Cut Matters More in Lab Grown Diamonds
Here is a detail that does not come up often enough. Lab grown diamonds quality is exceptionally consistent. More than 95% of lab grown diamonds entering the market today fall within a narrow and very high range of colour and clarity.
This means colour and clarity, while still important, are less likely to be the deciding factor in how your diamond looks.
Cut becomes even more consequential as a result. When you are choosing between two lab grown diamonds of similar colour and clarity, cut grade is the variable that separates a diamond that looks alive from one that looks like it is just sitting there. The light performance of an excellent cut lab diamond is not just better on paper. It is visible in any room, under any light source.
How Diamond Cut Grade Is Determined
The proportions of a diamond determine how light moves through it. Crown angle, pavilion depth, table size, girdle thickness: each of these measurements influences whether incoming light exits through the top of the diamond (where you want it) or leaks out through the sides and bottom (where it is wasted).
A pavilion that is too deep pushes light out the sides. A pavilion that is too shallow causes light to escape through the bottom. A table that is too large or a crown that is too flat reduces fire. These are not abstract issues. They translate directly into how the diamond looks on the hand.
GIA's research found that no single set of proportions defines the perfect cut. Multiple combinations of angles and measurements can produce an Excellent grade because human perception allows for some variation. What matters is that the combination works, all the proportions supporting each other in delivering maximum light return.
Beyond the Grading Report: Seeing Quality in Real Life
A grading certificate for a lab grown diamond lists its cut, polish, symmetry, colour, clarity, and carat weight. Whether issued by IGI or SGL, it provides an objective assessment of the diamond's characteristics and serves as an important benchmark when comparing options.
But there is one thing no certificate can fully capture: how the diamond interacts with light in everyday life.
Numbers and grades tell part of the story. The visual experience tells the rest. The way a diamond brightens under daylight, reflects light during an evening dinner, or catches your eye in a passing mirror cannot be communicated through a grading report alone.
This is why, at Keemti, we encourage you to look beyond specifications and experience the diamond itself. Across our collection, every piece is designed to showcase how a well-cut diamond performs beyond the certificate. Because while lab grown diamond grading reports help validate quality, the true test of a diamond is how it makes light come alive.
Cut Grade and the Pieces We Design at Keemti
Every Keemti solitaire and diamond piece is selected with cut grade as the first filter, not an afterthought. When we work on a design, whether it is a piece from our Essentials that you reach for every day or a statement piece from our Floral collection that earns a second look, the diamond in it has to perform.
A beautifully designed setting cannot compensate for a diamond that does not sparkle the way it should.
Lab grown diamonds quality at this level means you are not paying for the history of the diamond or the supply chain behind it. You are paying for the diamond in front of you, and what it does when the light finds it.
One More Thing Worth Remembering
The diamond cut grade is the only one of the 4Cs that is entirely determined by human craft. Colour and clarity are properties of the diamond as it forms. Carat weight is a measurement. But cut is a decision made by the person who shapes the stone, guided by skill, precision, and an understanding of how light behaves.
Here at Keemti, when a diamond is cut to Excellent, it is the result of hundreds of decisions made correctly, one after another. That level of craftsmanship is what makes an excellent cut lab diamond worth specifying by name, not just accepting whatever comes with a ring you liked the look of.
Diamond shapes, sizes, and settings may vary, but the true beauty of a diamond lies in how precisely it is cut. The right proportions allow light to move through the diamond beautifully, creating the brilliance and sparkle that make each piece memorable.
FAQs
What is a diamond cut grade?
A diamond cut grade measures how well a diamond’s proportions, symmetry, and polish allow it to reflect light and create brilliance.
Is cut grade more important than carat weight?
Carat determines size, but cut determines sparkle. A well cut diamond can appear more brilliant than a larger diamond with a lower cut grade.
Does cut grade affect lab grown diamonds quality?
Yes, cut grade plays an important role in lab grown diamond quality as it directly influences how bright and lively the diamond appears.
