Last Updated on 07/10/2022 by Above Diamond
As you may know, the “Cut” is what determines the beauty and sparkling brilliance of a diamond, and in turn, its value.
A well-cut diamond will increase its fire and brilliance. So, when you’re planning to buy a diamond, it makes sense to choose one that shines and sparkles the most, right?
What is a Diamond Cut?
A diamond cut refers to how well a diamond has been shaped in terms of symmetry.
We usually focus on factors like depth and the angles within the diamond. While these details can seem complex for those unfamiliar with diamond grading, they all contribute to the overall beauty of the diamond you’re planning to buy.
Here are the key factors that set a diamond’s value:
- Proportions: table, width, and depth
- Symmetry
- Brilliance
- Fire
- Scintillation
- Finishing/Polish
By now, you might feel overwhelmed with all the details, so let’s focus on the first factor: Proportions—Table, Width, and Depth. This is widely accepted as the most important factor in the diamond industry.
Diamond Table
The diamond table is measured by dividing the width of the table (the area on the diamond’s face) by the center length of the diamond (measured from the farthest left to the farthest right point).
Example: If the table has a width of 3.5 mm and the center length is 6 mm, the diamond has a table percentage of 58%.
If the table is too large, light escapes through the top of the diamond, reducing brilliance. If it’s too small, light gets trapped, making the diamond look cloudy and dull.
For round brilliant cut diamonds, the ideal table percentage for the best fire is between 54% and 60%, although other proportions also matter.
Diamond Width
Diamond width is measured from one edge (girdle) to the opposite edge. This measurement helps evaluate symmetry, which varies from shape to shape.
Diamond Depth
Diamond depth is the height from the bottom point (cutlet) to the diamond table, measured in millimeters and percentage.
To calculate the percentage, divide the diamond’s depth by its width.
Example: A diamond with a depth of 4 mm and a width of 4.5 mm has a depth percentage of 88.8%.
A shallower diamond may appear larger but less brilliant, while a deeper diamond might look smaller and dull due to poor light reflection.
Diamond Cut vs. Diamond Shape – What’s the Difference?
Diamond cut and diamond shape are often confused but are actually very different.
Diamond shape refers to the physical appearance, such as round, emerald, princess, or heart-shaped. Non-round diamonds are typically called “Fancy Shaped Diamonds.”
Diamond cut refers to the quality of the angles, symmetry, dimensions, and how well the diamond reflects light. For example, two heart-shaped diamonds might look similar, but one can have a superior cut that makes it much more brilliant.
In short, if a diamond has an excellent cut, like an ideal cut diamond, it will have better brilliance and fire.
Diamond Cut Proportions
Diamond cut proportions are what give the diamond its brilliance by determining how light reflects. Proportions take the width, length, and angles into consideration, and are key in objectively determining the beauty of a diamond.
What Happens If a Diamond Is Too Shallow?
When a diamond is too shallow, light passes straight through the bottom instead of reflecting back, resulting in little brilliance. Shallow diamonds might appear larger, but they lack sparkle.
What Happens If a Diamond Is Too Deep?
If a diamond is too deep, light refracts inside the diamond too quickly, causing less brilliance. Additionally, deep diamonds often look smaller than diamonds of the same carat weight because of their narrow table.
Which Proportions Are the Best?
In simple terms, diamonds with well-balanced proportions allow light to pass and reflect perfectly inside the diamond. This reflection results in brilliance and fire as the light exits through the table.
GIA uses terms like “Excellent,” “Triple Excellent,” or “3EX” to guarantee a diamond’s proportions, symmetry, and polish. These diamonds tend to be brighter and more valuable, which is why we often recommend prioritizing the cut, especially if you’re on a budget.
If you’re unsure about which cut to choose, reach out to us for expert advice.
GIA Diamond Cutting Terms
The GIA (Gemological Institute of America) is the most trusted institution in the diamond industry, known for its unbiased grading system.
GIA’s grading system includes terms you’ll want to know when considering a diamond’s cut:
- Excellent (EX): Best brilliance, with light fully reflecting through the table.
- Very Good (VG): Great brilliance, nearly indistinguishable from Excellent to the naked eye.
- Good (G): Good brilliance, offering sparkle at a more budget-friendly price.
- Fair (F): Decent brilliance, with some light escaping through the bottom or sides.
- Poor (P): Little to no brilliance, as most light escapes, making the diamond appear dull.
While GIA guarantees many diamonds with an “Excellent” grade, it’s worth noting that not all are equally stunning. In our experience, around 25-30% of diamonds labeled “Excellent” may not meet the same high standards as others. We only select diamonds that truly live up to the highest standards for our customers.
What Is a Triple Excellent Diamond?
A Triple Excellent (3EX) diamond is one that receives the highest grade for the following three criteria:
- Proportions: Ideal table, width, and depth.
- Symmetry: Perfectly aligned angles and facets.
- Polish: Flawless shine and texture.
If all three factors are rated Excellent, the diamond is classified as a 3EX or Triple Excellent diamond.
You can check your diamond’s brilliance by shining a light on it and observing how it sparkles. Always refer to your diamond report to verify these qualities.
The Diamond’s Cut Plays a Role in Pricing
The precision of a diamond’s cut significantly impacts its price. Symmetrical diamonds reflect light beautifully, enhancing their value. Investing in a better cut often provides more long-term value than simply opting for a larger carat weight.
Focusing on cut is a wise decision because a well-cut diamond will outshine those with larger carat weights but poorer cuts.
Read more: Our guide to buying 1 carat diamonds
Conclusion: When Selecting a Triple Excellent Diamond, Consider Other Factors Too
When purchasing a diamond, we recommend prioritizing the cut, no matter where the diamond is certified—be it GIA, HRD, or IGI. If the cut is poor, the diamond will lack brilliance.
Alongside the diamond report, consulting an expert can help ensure you find a diamond that suits your style and meets your needs perfectly.
We’re here to guide you through the process of selecting the highest quality diamond that fits your budget, ensuring you get the most beautiful diamond possible.
If you need any advice, we’re happy to recommend only the best options for you.
Read more: How to easily and precisely measure ring sizes at home
