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Diamond Depth and Table: How to Choose the Perfect Diamond

Diamond Depth and Table: How to Choose the Perfect Diamond

When looking to buy a diamond, there are a plethora of factors that you should take into consideration before you make the purchase. Most of these aspects fall under what experts call the four Cs of diamonds – cut, carat, color, and clarity.

If you dive a bit deeper, you’ll notice some other aspects, such as diamond depth and percentage.

These two elements play vital roles in a diamond’s beauty and overall appearance. If you want to learn more about diamond depth and table and what you should pay close attention to, be sure to read this article until the end.

What Is Diamond Depth?

Out of the four Cs, a diamond’s cut is the one that shoppers generally pay the most attention to. This is due to the significant impact that the cut has on the overall appearance of the diamond. Diamond’s cut affects its appearance in three fundamental ways and these include

It’s important to note that the diamond’s depth plays a significant role in determining the diamond’s brilliance, fire, and scintillation. In this case, depth is simply defined as the stone’s height is measured from table to culet, generally in millimeters.

The diamond’s culet refers to the bottom tip of the diamond. Being the posterior facet, it’s not possible to see it with the naked eye. An ideal culet is typically graded as “small” or “none”. Conversely, the diamond’s table refers to the topmost facet of the diamond, and it’s regarded as the biggest facet of the stone.

As we already indicated, a diamond’s depth plays a pivotal role in influencing how light traverses through the diamond. It mainly dictates the amount of light that’s reflected back to the viewer’s eyes. For example, in shallow diamond cuts, the light often travels through the diamond significantly fast before exiting it through the pavilion without making any reflections. 

However, if the diamond is cut too deep, the stone may have poor sparkle, resulting in a deceptively more diminutive appearance. 

This underscores the importance of selecting a diamond with an ideal depth since, with the right depth, a stone should allow the maximum amount of light to pass through it, striking each facet of the pavilion and ensuring that most of the light is reflected back to the viewer’s eyes.

What Is The Ideal Diamond Depth?

Right of the bat, it’s crucial to remember that the ideal diamond’s depth varies based on the stone’s shape and cut. The depths are generally graded, ranging from Poor to Excellent grade.

Since the diamond’s depth is such an essential element that dictates the aesthetic appeal and the diamond’s light performance, it’s typically captured on a diamond grading report. When viewing the report, you can spot two different measurements which are both described as diamond’s depth.

The first measurement denotes the stone’s total height and is expressed in millimeters, whereas the second measurement has to do with the diamond’s depth percentage.

Ideal Diamond Depth Percentage

To calculate the diamond’s depth percentage, you would need to divide the total height of the diamond by the average diameter of the stone. Following that process, you would multiply the answer by 100.

If a diamond’s average diameter is 10 millimeters and the diamond has a total height of 7 millimeters, you would arrive at the diamond’s depth percentage as follows:

  • Total height/average diameter x 100
  • Divide 7 by 10, which gives you 0.7 millimeters
  • Multiply 0.7 by 100, which gives you 70%

While there’s no ideal diamond depth, there are certain recommended diamond depth ranges that might help you as you shop for your gemstone. The following are the ideal ranges for diamond depth for some of the popular diamond shapes out there:

Diamond ShapeIdeal Depth Percentage Range (%)
Round Brilliant Cut DiamondsFrom 59 to 62.6
Radiant Cut DiamondsLess than 67
Princess Cut DiamondsFrom 68 to 75
Pear-shaped DiamondsLess than 68
Oval Cut DiamondsLess than 68
Marquise-Cut DiamondsFrom 58 to 62
Heart-shaped DiamondsFrom 56 to 62
Cushion Cut DiamondsFrom 61 to 68
Emerald Cut DiamondsFrom 61 to 68

As highlighted before, diamond’s depth is critical in helping customers grab hold of the best gems for them. But how does one leverage this important aspect of a diamond’s structure while shopping for their dream stone?

First, you would need to decide which diamond cut you want. For example, if you’re searching for a round brilliant cut, you’ll first request the seller to produce several round brilliant cut diamonds that fit your preferred description.

Afterward, you’ll visually inspect the diamonds to make sure that they have the physical characteristics you’re looking for. Out of the four Cs, you’ll find out that the diamond cut is the hardest factor to evaluate.

To ascertain that you’re receiving the right diamond cut, be sure to ask for a diamond grading report. On that report, look for the diamond depth percentage assigned to the round brilliant cut diamond you want to buy. 

If, after thoroughly skimming through the diamond grading report, you realize that the diamond depth percentage is between 59% and 62.6%, you can confidently claim that the stone has been perfectly cut.

On the other hand, a diamond depth percentage outside the range we recommended means the stone hasn’t been well cut, which can lead to a less brilliant and sparkly diamond.

What Is A Diamond Table?

A diamond table refers to the flat, square-shaped, top-most facet of a diamond. It’s so named because of the position that it occupies as well as the role it plays in the gemstone’s structure.

The diamond table serves to refract the light rays that pass through the gem and direct the light rays to different facets of the diamond. Like the diamond depth, the diamond table defines the diamond’s brilliance, fire, and scintillation based on how it handles the light rays that enter the diamond.

The size of the diamond’s table is one of the critical factors that impact the diamond’s appearance. There’s a common misconception that the larger the table is, the more efficient it can handle the entering light. 

However, larger diamond tables don’t necessarily mean better light-handling properties. If a diamond’s table is too big, the upper facets of the gem may not have enough room to disperse light. Similarly, if the diamond’s table is too small, a low amount of light will enter the diamond, thereby lowering its brilliance.

What’s The Ideal Diamond Table Size?

Naturally, you would expect bigger diamonds to have proportionately bigger table sizes and therefore higher table percentages.

However, depending on how the gemstone is cut and faceted, the table’s size may not always be relative to that of the entire diamond. Generally, customers have to make a trade-off between brilliance and fire when deciding upon a suitable table size for their stones.

Because of the variance in the physical size, jewelers often rely on the table percentages when they grade their gems as opposed to the table size.

The table size is assigned a score between Excellent and Poor on the diamond grading report, while the diamond table percentage is indicated in numbers.

Ideal Diamond Table Percentage

According to the Gem Society, a diamond’s ideal percentage should be between 52% and 62%. However, those percentages boil down to individual preference, as you might already know. In addition, an ideal table percentage is based on the overall size and shape of the gem.

A diamond table percentage is calculated by dividing the overall table width by the total width of the stone and then expressing the answer in percentage. For example, if a diamond has a width of the table of 10 millimeters and the total width of 7.5 millimeters. In that case, you’ll calculate the table percentage as follows:

  • Table width/total width x 100
  • 10/7.5 = 0.75
  • 0.75 x 100 = 75%

The table below shows the ideal diamond percentage ranges based on some of the popular cuts:

Diamond Shape Ideal Table Percentages (%)
Round Brilliant Cut DiamondsFrom 53 to 58
Radiant Cut DiamondsFrom 61 to 69
Princess Cut DiamondsFrom 67 to 72
Pear-shaped DiamondsFrom 53 to 63
Oval Cut DiamondsFrom 53 to 63
Marquise-Cut DiamondsFrom 53 to 63
Heart-shaped DiamondsFrom 53 to63
Cushion Cut DiamondsFrom 61 to 67
Emerald Cut DiamondsFrom 61 to 69

Reading from the table, the numbers don’t vary as much as one would think. However, these seemingly tiny variances have an exponential impact on the overall appearance of the gemstone. 

Similar to the depth of the diamond, understanding the ideal diamond table percentage that the shape ought to have is extremely important when shopping for a diamond.

How To Select The Perfect Depth And Table Sizes?

It’s essential to keep in mind that out of the four Cs, the diamond cut is the most complex element to analyze because what appears like a round shape when viewed by the naked eye might actually be an oval shape.

Additionally, even if you can distinguish different diamond shapes, you may not be able to examine technical details relating to the diamond’s facets. Challenges like these were the inspiration that led to the invention of depth and table percentages.

As a buyer, the first thing you should ensure is that the stone you’re purchasing is coupled with a diamond grading report. Moreover, one of the reputable diamond grading labs must issue the grading report. 

Finding a diamond grading report shouldn’t be an issue since diamonds certified by trusted grading labs such as the GIA and AGS often come with a grading report that indicates the gemstone’s depth and table percentages, among other aspects of the diamond.

Be sure to go through the diamond grading report before you check the stone’s depth and table measurements. Try to make sense of its cut grade because the depth and table percentages are finer elements of the diamond’s cut. Make sure that the diamond is of your desired cut grade first.

One notable benefit of ideal diamond depth and table percentages is that they don’t impact your budget that much. Since the values are expressed in percentages, they remain constant no matter the diamond’s weight, clarity, or color.

Therefore, a diamond weighing 0.8 carats can have a depth and/or table percentage that’s consistent with some other diamond that weighs 10 carats. These two gemstones will have similar light-handling properties with other elements kept constant.

Why Should You Select Depth And Table Correctly?

You should pay close attention to the depth and table percentages because these two aspects of a diamond cut influence the stone’s light performance significantly. Collectively, a diamond’s depth and table impact the stone’s brilliance, fire, and scintillation. 

In other words, depth and table influence how sparkling your diamond is, and since we all know that appearance is the primary consideration when buying any type of jewelry, one ought not to skip this critical step.

Another reason to properly select the depth and table is that they dictate the diamond’s price. It’s equally important to keep in mind that jewelers often leverage these seemingly trivial aspects while pricing their gemstones.

You’ll often note that two diamonds that are similar in other factors come with different price tags based on their depth and table ratings.

Bottom Line

Both the diamond depth and table ratings are designed to aid customers in selecting their ideal diamond. However, even if a stone has values that fall within the ideal ranges, diamonds possess other quality parameters that you should take into consideration. 

Above all, keep in mind that the most critical factor is your personal preference and taste – if a gemstone appears excellent in your eyes, nothing else matters.