About Diamond Depth and Table

When shopping for a diamond, there are numerous factors that you should consider before honing in on your ideal stone. Most of those factors broadly fall under what experts refer to as the Four Cs of diamonds that include cut, color, clarity, and carat weight. Each one of these factors impacts the aesthetic appeal as well as the price of a diamond.

Diamonds are measured in carats; one carat equaling 0.2 grams or 0.007 ounces. Diamonds of a higher carat weight are costlier than those that weigh less provided that all the other factors remain constant.

Besides the carat weight, diamonds also come in numerous color hues. In terms of diamond color, the general pricing rule is that the more colorless the appearance of stone, the costlier it is. However, there’s an exception to that rule when it comes to red and pink diamonds.

Clarity refers to the number of visible inclusions or blemishes that a diamond possesses; responsible for marrying their appearance. This connotes that the more the blemishes in a diamond, the considerably lower the cost as compared to its flawless counterpart.

The last element of the four Cs is the cut, and, as you shall find, there are many diamond cuts that one can happen upon. Moreover, contrary to popular perception, the cut of a diamond isn’t the same as its shape. Instead, it refers to a seamless combination of the diamond’s proportions, polish, and symmetry, and to how that combination affects the overall aesthetic appeal of the stone. For instance, round diamond cuts aren’t necessarily round in shape.

What is Diamond Depth?

Out of the four Cs that have been elaborated upon, it’s the cut of a diamond that shoppers often pay the most attention to: this happens on account of the significant effect that a diamond cut has on the overall appearance of the stone.

The cut of a diamond affects the appearance of the stone in three fundamental ways. These include:

• Brilliance – The measure of the brightness of both reflected and refracted lights;
• Fire – How a diamond disperses light into various flashes of visible color; and
• Scintillation – How a diamond sparkles when you move it.

It is pertinent to note that the depth of a diamond plays a pivotal role in determining the stone’s brilliance, fire, and scintillation. Depth, in this case, is simply defined as the height of the stone as measured from the culet to the table, usually measured in millimeters.

The culet of a diamond refers to the bottom tip of the stone. Being the bottom-most facet, it’s impossible to be able to see it with the naked eye. An ideal culet is usually graded as either “small” or “none.” On the other hand, the table of a diamond refers to the topmost facet of the stone; also regarded as the largest facet of the stone.

As we’ve already indicated, the depth of a diamond plays a significant role in influencing how light travels through a stone. It particularly determines the amount of light that reflects back to the observer’s eye.

For instance, in shallow diamond cuts, light often travels through the stone significantly fast before leaving it via the pavilion without creating any reflections. But, when the cut is too deep, the diamond may have poor sparkle, causing it to appear deceptively smaller. This underscores the importance of choosing a diamond of an ideal depth; for, with the right depth, a diamond should allow maximum light to pass through it, striking each pavilion facet at an angle ensuring that most of the light reflects back to the observer’s eye.

What is The Ideal Diamond Depth?

Right off the bat, it’s important to remember that the ideal depth of a diamond varies, depending on the shape and cut of the stone. The depths are usually graded, ranging from Poor to Excellent.

Since the depth is such a crucial aspect that determines the aesthetic appeal and the light performance of a diamond, it’s usually captured on a diamond grading report. In the report, you’ll spot two different measurements that are all described as diamond depth.

The first measurement, expressed in millimeters, denotes the total height of the diamond; while the second has to do with the depth percentage of the diamond.

Ideal Diamond Depth Percentages

To calculate the depth percentage of a diamond, you would be required to divide the total height by the average diameter of the stone following which process you would multiply the answer by 100. If, in what ensues, a diamond’s average diameter is 10 millimeters and the stone has a total height of 6 millimeters, you would arrive at the depth percentage as follows:

> (Total Height/Average Diameter) x 100.

> Divide 6 by 10, which gives you 0.6 millimeters.

> Multiply 0.6 by 100, which gives you 60%.

While there are no ideal diamond depths, there are certain recommended depth ranges that might guide you as you shop for a suitable gem. The following are the ideal diamond depth ranges for the popular diamond shapes out there:

DIAMOND SHAPE	IDEAL DEPTH PERCENTAGE (%)
Escher or Emerald-cut diamonds	From 61 to 68
Cushion cut diamonds	From 61 to 68
Heart-shaped diamonds	From 56 to 62
Marquise diamonds	From 58 to 62
Oval cut diamonds	Less than 68
Pear-shape diamonds	Less than 68
Princess cut diamonds	From 68 to 75
Radiant cut diamonds	Less than 67
Round diamonds	From 59 to 62.6

 

As highlighted before, the depth of a diamond is crucial in helping customers grab hold of the best diamonds for them. But how do you leverage this critical aspect of a diamond structure while shopping for your dream gemstone?

First, you would need to determine the diamond cut that you desire. For instance, if you’re looking for a round diamond, you’ll first request the vendor to produce a few round diamonds that fit the description of your preferred stone. Afterwards, you’ll visually examine the diamonds to ensure that they possess the physical characteristics that you’re looking for.

Out of the Four Cs, you’ll discover that the cut is the most difficult aspect to determine. To ascertain that you’re getting the right diamond cut, ask for a diamond grading report from the seller. Now, on that report, look for the depth percentage assigned to the round diamond that you’re purchasing. If, after thoroughly skimming through it, you realize that the depth percentage is between 59 and 62.6%, you can confidently claim that the diamond has been perfectly cut and faceted. On the other hand, a depth percentage score outside the recommended range means the diamond hasn’t been well-faceted, which may bear upon the stone’s sparkle and brilliance.

GIA proportion chart for 60% table. Excellent candidates are in dark blue

 

What is a Diamond Table?

A diamond table is the flat, topmost, square-shaped facet of a diamond and is so named due to the crucial position that it occupies, and the role it plays, in the diamond structure.

The fundamental function of a diamond table is to refract the rays of light that pass through the diamond and to direct the said rays to different facets of the stone. Kindred to the depth, a diamond table also defines the fire, brilliance, and scintillation of a diamond, depending on how it handles the light that enters into the stone.

The size of a diamond’s table is one of the crucial factors that affect the appearance of the diamond. There is a common misconception that the bigger a diamond table is, the more efficient it can prove at handling light. However, bigger diamond tables don’t necessarily translate to better light-handling properties; for if a diamond table is too large, the upper facets of the stone may not have sufficient room to disperse light. Similarly, if the table is too small, minimal light will penetrate through the diamond, thereby diminishing its brilliance.

What’s The Ideal Diamond Table Size?

Naturally, you would expect larger diamonds to have proportionately larger table sizes—and hence higher table percentages. But depending on how the diamond is cut and faceted, the size of the table may not always be relative to that of the entire stone. In most cases, consumers have to make a trade-off between fire and brilliance when trying to decide upon the suitable table size for their diamonds.

Due to variance in the physical size of diamond tables, jewelers usually rely on the table percentages when grading their diamonds as opposed to the table size. On the diamond grading report, the table size is assigned a score between Poor and Excellent, while the table percentages are indicated in numbers.

Ideal Diamond Table Percentage

According to the Gem Society, the ideal table percentage of a diamond should range between 52 and 62%. But, as you shall be rendered aware, those percentages come down to individual preferences. Also, an ideal diamond table percentage depends on the overall size and shape of the stone.

A diamond table percentage is arrived at by dividing the overall width of the table by the total width of the diamond and subsequently expressing the answer in percentage. For instance, if a diamond has a table width of 10 millimeters and a total width of 8 millimeters, you’ll arrive at the table percentage as follows;

> (Table Width/Total Width) x 100

> 10/8 = 0.8

> 0.8 x 100 = 80%

The table below illustrates the ideal diamond table ranges depending on the cut;

DIAMOND SHAPE	IDEAL TABLE PERCENTAGES (%)
Escher cut diamonds	61 – 69
Cushion cut diamonds	61 – 67
Emerald cut diamonds	61 – 69
Heart-shaped diamonds	53 – 63
Marquise shape diamonds	53 – 63
Oval diamonds	53 – 63
Pear-shaped diamonds	53 – 63
Princess cut diamonds	67 – 72
Radiant diamonds	61 – 69
Round diamonds	53 – 58

 

Reading from the table above, the numbers don’t appear to vary significantly. However, those seemingly small variances have exponential effects on the overall brightness and appearance of a diamond. Similar to a diamond’s depth, understanding the ideal table percentage that the cut ought to have is invaluable when shopping for a gemstone.

How to Choose the Perfect Depth and Table Sizes for Your Diamond?

It’s crucial to remember that out of the Four Cs, the diamond cut is the most difficult aspect to analyze owing to the fact that what appears like a round shape to the naked eye may actually be an oval shape. And, even if you’re astute enough to distinguish between different diamond shapes and cuts, you may not be able to analyze the technical details relating to the stone’s facets. Such challenges were the inspiration behind the invention of depth and table percentages.

As a consumer, the first thing to ensure is that the diamond you’re buying is coupled with a grading report. Furthermore, the grading report must be from a reputable diamond grading lab. Finding a diamond’s grading report oughtn’t be a problem since diamonds certified by renowned grading labs – such as the Gemological Institute of America (GIA) and the American Gem Society (AGS) – do often come with a report that indicates the stone’s depth and table percentages. Go through the report, and, before you check the depth and table measurements of the diamond, make sense of its cut grade: this is so because although the depth and table percentages are finer aspects of a diamond’s cut, you need to ensure that the stone is of your desired cut grade first.

For example, you could be trying to make a choice between a diamond cut grade of Super Ideal Make and one of an Ideal Make. Compared side by side, the diamond graded Super Ideal Make is definitely superior. However, if you’re making a comparison between two diamonds, each with a cut grade of Super Ideal Make, you may now compare their depth and table percentages in which case, the stone with a higher depth or table percentage within the ideal range will have better light performance.

One notable benefit of ideal depth and table percentages is that they don’t affect your budget significantly. Given that the values are expressed in percentages, they remain constant regardless of the weight, color, or clarity of your diamond. Therefore, a diamond weighing 0.5 carats can have a depth or table percentage that’s consistent with another diamond weighing 100 carats. With other factors kept constant, these two stones will have similar light-handling properties.

Why Should You Choose Depth And Table Correctly?

One reason, among others, on account of which you need to exercise diligence when choosing a diamond depth and table is that these are the two primary aspects of a diamond’s cut that influence its light performance. Collectively, a diamond’s depth and table affect the brilliance, fire, scintillation, and luster of a diamond. In simpler terms, they influence how sparkling your diamond is, and because we all know that appearance is the main consideration when shopping for any jewelry, one ought not to skip this inevitable important step.

Another reason to correctly choose the depth and table is that they determine the price of a diamond. It’s equally important to remember that jewelers usually leverage these seemingly trivial details while pricing their diamonds. You’ll often note that two stones that are similar in other aspects come with different price tags depending on their depth and table ratings.

Both the diamond depth and table measurements are designed to help shoppers hunker down on their ideal stones. However, even if a diamond has values that fall within ideal ranges, there are other quality parameters that you need to take into account. Above all, remember that the most important factor is your personal tastes and preferences; if a diamond appears excellent to your eyes, everything else fails to matter.

Credit: Sharif Khan on 25th Dec 2020