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Understanding The Importance Of Diamond Depth And Table

By Gary A.

Edited by Brian M.

Published Jul 29, 2022

Edited on Oct 15, 2024

When it comes to maximizing sparkle, understanding diamond depth and table proportions plays a key role in ensuring your stone shines as brilliantly as possible.

Navigate This Guide:

  • Introduction
  • 7 Practical Tips for Examining Diamond Depth and Table When Buying an Engagement Ring 
  • Setting the Stage: The Role of a Diamond’s Table and Depth
  • Diamond Table – The Window to Sparkle 
  • Table Size and Its Effect on Brilliance 
  • Understanding Table Percentage
  • The Depth Factor – Reflecting Beauty Within
  • Conclusion
  • 8 FAQs

Introduction

By now, you likely already know how the Four Cs affect a diamond’s appearance. Namely, how cut impacts sparkle more than any other factor – and, for that reason alone, how important it is to get it right. But what does ‘getting it right’ even mean? For most of us, cut is easily confused with shape – a decision that comes down to personal preference, rather than anything objective or measurable.

Still, as one of the Four Cs, cut is every bit as important as the rest – and, in arguably, more important than any other for those looking to ensure that light will dance across the surface of your ring in a fantastic display of brilliance and fire.

There are multiple factors influencing the strength of a diamond’s cut, from the surface to the mirror-like depths of the stone.

Before we dive deeper into the specifics, here are some practical tips to help guide your decision-making process:

7 Practical Tips for Examining Diamond Depth and Table When Buying an Engagement Ring 

  • Tip 1: Understanding the Ideal Proportions for Specific Shapes: Different diamond shapes have unique ideal table and depth percentages. For instance, round diamonds typically have an ideal table percentage of 53-58% and a depth percentage of 59-62.3%. Before purchasing, research the ideal proportions for the specific shape of the diamond you are interested in to ensure optimal brilliance and fire. 
  • Tip 2: Checking the Diamond’s Grading Report: A diamond’s grading report, provided by reputable labs like GIA or EGL, includes detailed information about its table and depth percentages. Compare these numbers with the standard ideal ranges for the specific diamond shape. This report is a crucial tool in assessing whether the diamond falls within the desired proportions. 
  • Tip 3: Visual Inspection for Balance and Symmetry: Observe the diamond closely to check if the table and depth proportions appear balanced. The table should not be disproportionately large or small compared to the rest of the diamond. A well-proportioned diamond will have a harmonious and symmetrical appearance, enhancing its overall beauty. 
  • Tip 4: Assessing Light Performance and Brilliance: Evaluate the diamond under different lighting conditions to see how light plays through it. A diamond with ideal depth and table proportions will exhibit high levels of brilliance (white light reflection) and fire (color dispersion). If the diamond appears dull or lacks sparkle, it may have suboptimal table and depth measurements. 
  • Tip 5: Considering the Impact of Proportions on Diamond Appearance: Be aware that diamonds with depths or tables outside the ideal range can appear larger or smaller than they actually are. A deep diamond might look smaller in surface area but have more weight at the bottom, while a shallow diamond might look bigger but lack depth and brilliance. 
  • Tip 6: Analyzing the Overall Cut Quality: The cut quality, which includes depth and table, is one of the most important factors in a diamond’s appearance. A well-cut diamond will efficiently reflect light, offering the sparkle that many desire in an engagement ring. Don’t just focus on carat size or clarity; the cut quality, especially depth and table, plays a pivotal role in the diamond’s allure. 
  • Tip 7: Balancing Table and Depth with Other Diamond Characteristics: Remember that while depth and table are crucial, they should be considered alongside other factors like color, clarity, and carat weight. The most visually appealing diamond will have a well-balanced combination of all these characteristics.

Now that you’ve got these practical tips, use Jeweler AI below to find the perfect engagement ring that suits your style and budget:

DEPTH AND TABLE - Cut-Anatomy-of-Diamond

Setting the Stage: The Role of a Diamond’s Table and Depth

The table and depth of a diamond are two separate factors, although they both strongly influence the quality of a diamond’s cut.

The table refers to the uppermost portion of the diamond, while, as the name suggests, a diamond’s depth refers to a very precise measurement made from the table to the culet – or, in other words, its lowest point.

Diamond Table – The Window to Sparkle 

The value of an excellent diamond cut is far greater than the sum of its parts, but it helps to know exactly what these parts are before you make a decision. When you break, say, a Round cut diamond’s cut down, you get the culet, the pavilion, the girdle, the crown and, of course, the table. This table plays a prominent role in sparkle, which means that it pays to know your stuff…

Understanding the Table: Its Role and Impact 

This is the flat surface at the very top of the diamond. From Round cuts to Emerald, the table will look a little different on every diamond shape, though it plays the same vital role regardless.

More specifically, the table is the largest facet the diamond features – although the precise size of the table varies. Even in diamonds of the same shape, the table size will differ significantly – a factor which will directly impact the quality of the stone’s cut.

Why? Because the table needs to let light into the diamond, while also refracting it into other areas. To accomplish both of these tasks, it must represent a pretty specific percentage of the diamond’s surface area – not an easy task, even for the most skilled of diamond cutters.

Table Size and Its Effect on Brilliance 

The table is an intrinsic part of any diamond. Its job is to allow light into the diamond, to disperse it between the diamond’s many facets, and to reflect it back from the pavilion and out the top of the diamond as brilliance and fire.

If you’re feeling like the diamond table is playing two totally different roles, you’d be right. It’s got to let in light, but also refract light onto the crown, rather than letting it straight back out the table. It’s got to be small enough to do that, but not so small that the diamond looks dull and sparkly.

As a result, getting the proportions of the diamond table right is absolutely vital to creating a good diamond – and it’s not easy. Thankfully, your job is a lot easier and simply involves getting to know the ‘ideal’ diamond table and depth – and knowing the trouble that can be caused by one that is out of proportion, even if it’s just a small amount.

When the table is too small…

The amount of light able to enter the diamond will be reduced, meaning that the diamond will not be able to sparkle as much as it otherwise could, even if it has been given excellent grades for clarity and color.

The beautiful sparkle diamonds are capable of creating depends on the complex pathway light takes through the many facets cut into the surface, and the fascinating internal structure. Of course, it also depends on the diamond’s ability to draw in light in the first place, since diamonds do not ‘create it’ for themselves.

As we mentioned before, the table is the largest facet a diamond has. It sits on the most prominent part of the diamond and, particularly when it has been set within a ring, will be responsible for drawing in most of the light that travels through the stone’s center.

So, an undersized table will fall short of doing its most important job properly and will limit the amount of light the diamond can transform into sparkle.

When the table is too big…

As we mentioned above, the diamond’s table needs to play two roles at once – roles that, for the most part, stand in opposition to one another. If the table comprises too much of the diamond’s upper surface, there will be noticeably less sparkle. Then again, if it comprises too little, the same issue will occur.

In order to be considered ideal, diamond tables need to be above a certain percentage, but below another. This can seem a little confusing until you get to know the ideal ‘range’ for your chosen diamond shape, and why it’s better to use percentages in the first place.

Understanding Table Percentage

Table percentage refers to the ratio that exists between the widest point of the diamond, and the width of the table. When it comes to grading a diamond’s cut, a certain percentage range has to be met in order for the diamond to be considered Excellent.

There is no universally ideal measurement for the table. It’s impossible to say that, say, a table with a measurement of 6mm is the best since this measurement would overwhelm some smaller diamonds, and look far too small on others. So, even if a diamond’s 6mm table turns out to be the perfect size for maximizing sparkle, it will be poor enough to take thousands of dollars off another diamond’s value.

This is why we are given table percentages, since an optimal percentage range will be pretty much the same whether you’re looking at a one carat diamond or a ten carat diamond (provided, of course, that they’re the same cut.

Diamond Table Ranges

For the traditional Round cut diamond, a table of between 56% and 59.9% is considered Excellent, while anything below 49.9 is Poor. Other cuts differ somewhat – and, in many cases, offer a little more leeway than the Round diamond when it comes to table percentage.

For instance, the ideal table percentage for square diamonds is much broader. The Radiant cut features an ‘Excellent’ table percentage of between 61% and 69.9%, while the Asscher offers a range of 60% to 65.9%.

Below, we’ve included a table of ‘Excellent’ and ‘Very Good’ table percentages for all of the most popular diamond shapes.

Shape‘Excellent’ Table % Range‘Very Good’ Table % Range
  Asscher  60% – 65.9%58% – 59.9%or66% – 69.9%
  Cushion (Square and Rectangle)  60% – 65.9%58% – 59.9%or66% – 69.9%
  Emerald  60% – 65.9%58% – 59.9%or66% – 72.9%
  Marquise  53% – 65.9%52% – 52.9%or63% – 65.9%
  Oval  55% – 62.9%52% – 54.9%or63% – 65.9%
  Pear  53% – 62.9%52% – 52.9%or63% – 65.9%
  Princess  67% – 72.9%60% – 66.9%or73% – 75.9%
  Radiant (Square)  61% – 69.9%57% – 60.9%or70% – 72.9%
  Radiant (Rectangle)  60% – 66.9%58% – 59.9%or67% – 70.9%
  Round  56% – 59.9%54% – 55.9%or60% – 60.9%

For anyone looking to buy a beautiful ring, of any size or shape, to set within an engagement ring (or any jewelry, for that matter), it is never advisable to go below an Excellent or Very Good cut grade.

Diamonds featuring a table that exceeds the shape’s ideal percentage range will have limited fire, while those that feature a table that falls below the shape’s ideal percentage range will fail to impress with their sparkle.

The Depth Factor – Reflecting Beauty Within

While a good size of table is vital to a diamond’s ability to produce plenty of fire and brilliance, that’s not the only factor diamond cutters, jewelers or, for that matter, you need to consider in order to get the best possible diamond for your money.

Depth Defined: More Than Just a Measurement 

Put simply, depth refers to the distance from the diamond’s table to its lowest point. Like the table, depth is most commonly conveyed as a percentage, rather than a measurement.

Why? Because, just as before, there is no ideal measurement for depth – although there is an ideal ratio or percentage.

This percentage is reached by dividing the height of the diamond by the width, and will once again determine whether it is Excellent, Very Good, Good, Fair or Poor. Again, you want to aim for Excellent or Very Good or risk a diamond with impaired light performance.

When we think of diamonds – and, more specifically, diamond engagement rings – it is much more common for us to picture that bird’s eye view. We imagine ourselves looking down on the table and crown of the diamond since when it is worn on the finger, this is the part that will be most prominent.

It is important to remember, however, that every part of the diamond influences that light performance you see dancing across the surface. In other words, a beautiful sparkle is only made possible by an all-round beautiful diamond.

round diamond and rough diamond in tweezers

When a Diamond is Too Deep

A diamond with less-than-ideal proportions will have a dulled sparkle, due to the fact that light is being refracted and lost through the pavilion (the bottom portion of the diamond), rather than the table.

This is similar to what happens when a diamond is cut too shallow. While the path light takes through a deep cut diamond will be totally different to the path light takes through a shallow cut diamond, the end result is pretty much the same – and just as undesirable in either case.

If light is lost through the pavilion rather than the table, then that all-important bird’s eye view will be what suffers the most. Looking down on the diamond, you will see less sparkle, and a diamond lacking the liveliness and shine of better proportioned stones, even if they feature the same shape and carat weight. 

Utilizing Our Diamond Depth and Table Chart 

There is no definitive answer to this question, although, as with the table percentage, there is an ideal depth percentage range into which any good diamond will fall.

The diamonds used in the center settings of engagement rings differ drastically in size, from below one carat to well over twenty – although not all of us can carry off Beyoncé’s 24 carat Emerald cut diamond. What this means is that there is no ‘recommended depth measurement’ out there that could apply to all diamonds, despite the fact that countless beautiful diamonds are cut and graded each year.

Similarly, no single measurement (or percentage) could apply to all of the diamond shapes out there, since each one boasts different proportions and varying numbers of facets.

So, just as before, here are the ideal diamond table and depth ranges for each shape. 

Shape‘Excellent’ Depth % Range‘Very Good’ Depth % Range
  Asscher  63% – 67.9%58% – 62.9%or68% – 69.9%
  Cushion (Square and Rectangle)  63 – 67.958% – 62.9%or68% – 69.9%
  Emerald  63% – 67.9%59% – 62.9%or68% – 69.9%
  Marquise  58% – 62.9%56% – 57.9%or63% – 65.9%
  Oval  58% – 62.9%56% – 57.9%or63% – 65.9%
  Pear  67% – 72.9%64% – 66.9%or73% – 74.9%
  Princess  67% – 72.9%64% – 66.9%or73% – 74.9%
  Radiant (Square)  61% – 67.9%59% – 60.9 %or68% – 69.9%
  Radiant (Rectangle)  63% – 67.9%59% – 62.9 %or68% – 69.9%
  Round  59% – 62.3%58% – 58.9%or62.4% – 63.5%

Conclusion

Diamond depth and table are two of the most significant factors behind the quality of the diamond’s cut, and, as a result, its sparkle.

Cut is crucial – it’s the deciding factor behind whether or not a diamond is worth your time or not. And, while cut comprises far more features than just depth and table, there really is no room for error when it comes to these two percentages.

It’s easy enough to tell yourself that a deep or shallow diamond won’t look too deep or too shallow once it is set within the ring, or that a smaller table adds to the unique ‘charm’ of the diamond, but that’s why it’s so important to understand how these two features will impact the stone’s light performance, and why you should never compromise on that.

8 FAQs

  • Q: What is the diamond table, and why is it important?
    A: The diamond table is the large, flat top facet of a diamond. It’s crucial for its role in allowing light to enter and exit the diamond, contributing significantly to the stone’s brilliance and fire.
  • Q: How does the depth of a diamond affect its appearance? 
    A: The depth of a diamond, which is the measurement from the table to the culet, influences how light is reflected within the diamond. Incorrect depth can lead to less brilliance, either by letting light escape too easily or not reflecting it effectively.
  • Q: What are ideal table and depth percentages for round diamonds? 
    A: For round diamonds, an ideal table percentage is typically between 53-58%, and the ideal depth percentage ranges from 59-62.3%. These proportions ensure the best balance of brilliance and fire.
  • Q: How do you calculate the table and depth percentages of a diamond? 
    A: The table percentage is calculated by dividing the diameter of the table by the diameter of the diamond. Depth percentage is found by dividing the diamond’s height by its average diameter.
  • Q: Can the table and depth percentages vary for different diamond shapes? 
    A: Yes, different diamond shapes have varying ideal table and depth percentages. For example, a princess cut diamond has different ideal proportions compared to an oval or emerald cut.
  • Q: Why aren’t all diamonds cut to ideal proportions? 
    A: Diamond cutters often have to balance between retaining carat weight and achieving ideal proportions. Market demand for larger stones and the original shape of the rough diamond can lead to variations in cut proportions.
  • Q: How do table and depth impact a diamond’s overall cut grade? 
    A: The table and depth are critical in determining a diamond’s cut grade, which affects how it interacts with light. Proper proportions ensure better light reflection and dispersion, contributing to the diamond’s overall brilliance and beauty.
  • Q: What should I look for in a diamond’s grading report regarding table and depth? 
    A: Look for the table and depth percentages in the report, and compare them to the ideal ranges for the specific diamond shape. Ensure these proportions align with standard grading scales for an excellent or very good cut.

Let JewelerAI guide you to the ideal balance of table depth and other key factors in finding your perfect diamond.