Diamond Cut

Diamond Cut

When you are in the market for the most ideal diamond for you, one of the main features that you must consider is the diamond cut and the shape. This is the most complex of the diamonds 4Cs which include, cut, carat, clarity, and color.

Why the diamond cut is important?

Many diamond professionals will consider the diamond cut to the be most important of the 4Cs. When a diamond such as the round brilliant is professionally cut, the facets will be aligned the right way causing great fire and brilliance in the stone.

When you walk into a crowded room, the light display will alert every eye to the diamond on the finger. A diamond is cut the right way, making compromises on the carat weight, the color and the clarity can be forgiven.

James Allen Diamonds

You will need to consider the diamonds cut grade. This indicates how well the stone has been cut. These factors are the key to picking the best diamond for that engagement ring.

After the diamond has been cut, it also needs to be polished to ensure maximum sparkle and brilliance. Symmetry is also an important aspect of the cut and all the facets need to be properly aligned and symmetrical. This ensures optimum light reflection by the facets and thus more brilliance.

To understand how light works in the diamond, it is crucial to learn about the different parts of the diamond. There are 5 main parts which we shall look at shortly and they include the table, the culet, the pavilion, the crown, the girdle.

What is involved in the GIA cut grade?

The GIA analyzed and evaluated different diamonds to find out why some were more appealing than others. It used computer modeling to try different proportions and later included the opinions of people.

Well over 70,000 people’s opinion was considered when making the cut grading system. In the end, 3 main factors were included in the cut grading system.

The first is the appearance of the diamond when observed face-up based on its fire, brilliance, and scintillation.

Second is the durability and the optimal weight as a result of the diamond cut.

And lastly the quality of the craftsmanship that goes into cutting the dominant and polishing the facets.

The face-up appearance and sparkle

The face-up appearance is an important consideration to anyone who is interested in a diamond and this is also why it is a major factor in the GIA cut grading system.

Simply put, this refers to the appearance of the diamond when viewed from above, similar to how someone would look at it when it is set on an engagement ring. It is the stone’s light interplay which captivates your eyes and this is referred generally as sparkle.

A diamond’s brightness is the reflection of the internal and external white light. The sparkling light that leaves the diamond and displays all the other colors of the rainbow it is called the fire of the diamond.

The sparkle, on the other hand, is the dark and light areas that shift within the diamond as the light source moves. Many people will refer to all these factors as sparkle. However, it is the interplay between them.

The importance of diamond proportions

The measurement of the facets, the pavilions, and the crown have a big impact on how a diamond appears when looked at face up. Keep in mind that the facets act like small mirrors. The placement of the facets owing to the type of cut will determine the behavior of light after it travels through the diamond and is then refracted back to you.

The proportions of a diamond will tell you how it will reflect its brightness, scintillation, and fire. As the GIA found out, however, there is not a single set of proportions that can really define a well-cut diamond. Much to the surprise of many, diamonds that have different proportions may be graded the same.

Two diamonds with different proportions may perform and reflect light differently and yet have the same impact on an observer. What this means is that it is important as a diamond shopper to look over and above the cut grading system and just pick a diamond that is most appealing to you based on your observations.

The table and depth of Diamond cuts

The table is the topmost part of the diamond. This section or facet is flat and essentially looks like a table, thus it’s named. Considering the dimensions of the table is important when picking the best diamond.

The table on diamonds will be measured in percentages. These are arrived at by dividing the width of the diamond table by the total width of the diamond. When you are evaluating diamonds of different sizes, the percentages will be of great help. This is because they allow you to get the ideal cut of any size diamond.

Note that it is not always the case that the bigger the table the better the diamond. If it too large, then the facet on the crown will not be able to disperse much light. On the other hand, if the table is very small then not much light filter through the diamond.

Of course, the size of the table will depend in part to the size of the diamond. This explains why jewelers and sellers will talk about table percentage. There is no one ideal table size for all diamonds. It will come down to the type of diamond cut.

The second most important factor to look at is the depth. This is the distance between the table and the culet which is the bottommost part of the diamond. It will also be referred to in percentages by dividing the depth by the total width of the diamond.

Each diamond cut has an ideal depth and table percentage. If you are looking to buy the largest diamond you can find, the depth will influence where the majority weight is located on the stone.

A lower depth will make the diamond appear much larger when viewed for the top, this is because the majority of the weight will be in the crown of the stone.

Also note that when a stone has a depth that is too shallow, the light will simply pass through the diamond without much of it being reflected. On the hand, if the depth is too deep then it will have a poor reflection of light inside the diamond resulting in less fire and sparkle.

The most ideal cut stone will reflect 100% of the light that gets into the table of the diamond and the crown. As an observer, you will see this as the fire, scintillation and the brilliance of the diamond.

The Round cut

As far as brilliant-cut diamonds go, the round but is at the top of the list. It was designed in the 1900s and features 57 facets that are carefully placed to reflect the most light. It can achieve the highest level of brilliance than any other type of cut.

The ideal proportions for the round cut diamond are:

Table 54-57%

Depth 60- 63%

The Princess cut

As a general rule of thumb, with princess cut diamonds avoid stones that have a table percentage that is greater than its depth percentage. It should be the opposite of the depth percentage being larger.

The best princess cut diamond will have a perfect square.

Table 63-70%

Depth 67-76%

The Cushion cut

The older cushion cut diamonds had fewer facets when compared to the modern cushion cut diamond. These feature more facets and therefore more brilliant. They look like round diamonds in appearance but not quite.

Table 56% to 63%

Depth 58% to 66%

The Emerald cut

Emerald cuts have different scintillations compared to another brilliant cut diamond. Instead of having smaller sparks of light these feature an on and off flashing pattern owing to their larger facets.

Table 61% to 68%

Death 60% to 65%

The Oval cut

Oval cuts have an ideal length to width ratio of 1.4 or 1.3. They can appear short and wide or long and thin. The oval cut diamond is prone to having the bowtie effect mainly at the center of the diamond. This tends to be the case with a stone that is either too deep or too shallow.

Table 54% to 58%

Depth 62% to 66%

The Pear cut

The ideal pear cut diamond should have a point that lines up perfectly with the apex of the arc. Also, both sides of the pear cut diamond should be mirror images of each other and completely symmetrical. The length to width ratio of the pear cut should be between 1.4 and 1.6.

Table 57% to 62%

Depth 58% to 64%

The Radiant cut

Radiant cut and princess cut may appear similar but their cuts and faceting are different. The radiant cut has concentric circles that start from the center while the princess cut is more linear resulting in a cross-section at the center.

Table 60% to 69%

Depth59% to 68%

The Marquise cut

This type of cut requires careful evaluation of the length to width radio perhaps more so than the other diamonds. While the ideal length to width ratio will come down to your personal preference, often it will be anywhere between 1.7 to 2.0.

Table 55 to 63%

Depth58% to 64%

The Asscher cut

It features step cuts similar to the emerald cut. They have a feel of sophistication and class about them. The Asscher cut also has a very distinctive X pattern at the center of the stone. The length to width ratio is 1.1 though this may also depend on your taste and preference.

Table: 59% to 65%

Depth 58% to 64%

Now that we’ve considered the ideal proportions for the fancy cut diamonds, note that it is crucial that you check and evaluate the stone yourself to be able to choose the ideal diamond for you. A certificate of the diamond is important but this will not provide you with the exact proportions and appearance of the diamond. Caution is always against buying a diamond blind.

Find a reputable seller who will provide you with images and a 360-degree video of the diamond that you are interested in.

In the end, the table and the depth will determine just how much the diamond is going to sparkle. Regardless of the size of the stone that catches your eye, you can be comfortable in knowing that the depth and the table are measured in percentages, and these are constant.

The diamond girdle and its importance

The girdle is the widest part of a diamond when looking at it from above. It is the perimeter of the stone and separates the crown of the diamond from the pavilion. This is the section of the diamond that rests on its settings.

Think of it as the circumference of the diamond. When evaluating your diamond, you want to take a closer look at the girdle. A very thin girdle is at risk of chipping when the diamond is being placed on its setting or when you are wearing it daily.

To ensure that the stone remains safe, it should be placed on its setting in the most efficient way to minimize contact with the girdle.

On the other hand, when the girdle is thick, the diamond will have great fire and brilliance. This, however, is when the stone has the right proportions.

The thickness of the girdle tends to concentrate the weight if the stone at its center. This will cause it to look very thin from the top compared to a stone of similar carat size and has a thinner girdle.

The ideal size for the girdle, however, should neither be too thick or too thin.

A diamond will be measured in different points around the girdle before being given a rating. If the thickest point around the girdle and its thinnest point fall within a certain range then it will be rated.

The girdle is rated between very thin and thick.

Extremely thin—is very prone to breaking or chipping care needs to be taken when setting the stone.

Very thin—while care should also be observed when setting the diamond, this is a good proportion.

Thin, medium—this is the ideal diamond or gemstone proportion.

Slightly thick, thick—this is an excellent to ideal diamond Proportion.

Very thick—this is a good diamond proportion

Extremely thick—more of the depth will be consumed by the girdle making it look even smaller.

The culet

This refers to the small point located at the very bottom or base of the pavilion. This is where all the facets of the pavilion are going to meet. In most cases, the facets at the pavilion will be uniformly cut and will meet at the dead deter resulting in no culet at all or a pointed cult.

If on the other hand, the facets are not meeting at a point then it is called a rough culet or a pointed culet or a polished culet. This will add one more facet to the total number.

The rating for the culet ranges from none, in case of a pointed culet to extremely large. To determine where the culet lies, the stone will be evaluated face up. In this way, professionals can determine the size. Then it will be viewed from the side to check the angle.  If it has a sharp angle, then this is no longer considered a culet but a facet.

When you observe a diamond from above which has a large culet, it can be easily seen. This explains why modern cutting standards are not very popular with rough culets. The culet will appear like a dark circle since light entering the diamond from the table will go right through without being reflected.

That said the absence of a culet means that the sharp point is at a high risk of chipping especially when being set. A small culet, on the other hand, creates a small circle at the center of the diamond when looking at it from above and will do an excellent job of reflecting light from the table. It is not likely to chip as well.

The pavilion

The pavilion refers to the bottom half of the diamond which lies under the crown it consists of three main parts of the diamond which include the girdle, the bottom facets, and the culet.

Often the pavilion will be hidden under the setting of the stone. That said it is still a very crucial aspect as it reflects light that gets into the diamond back to the observer. The result is brilliance and fire. Once understand the pavilion you will be better able to pick the best diamond for you or your loved one.

The pavilion has a big impact on how the diamond shines and sparkles. The light will enter the diamond through the crown and the table. It travels down to the pavilion where it meets the bottom facets which lie at an angle. These refract the light causing it to change the direction of travel. It will then eventually be reflected the observer by first being reflected the opposite pavilion and then eventually being directed up towards the table resulting in brilliance ad fire.

However, if the pavilion is set too low, then they will be little refraction resulting in little fire or brilliance. On the other hand, if the pavilion is set too high then the light will shine right through the diamond.

This, therefore, means that the diamond needs to have the bottom facets cut professionally and at the right angle for maximum reflection. A poorly cut diamond will not reflect light well enough and will have less sparkle.

Always take time to evaluate the cut of the pavilion when shopping for the ideal diamond. Note that the ideal range and depth of the diamond will come down to the shape and size of the stone.

The crown

The crown is the window of the diamond through which light gets in. It has a significant impact on the brilliance and sparkle of a diamond. Secondly, it will also act like a prism which disperses light resulting in the fire of the diamond.

The size of the crown will determine the amount of fire that a diamond can give off. And it has a third function which is to bend light. In this way, you see a shifted reflection of light that is different from what you would view through the table.

It results in more virtual facets with each reflecting its light and resulting in sparkle and brilliance.

The angle of the crown is important as it will compensate the bent light by the pavilion facet. Because of this fact, a steeper pavilion facet should have a shallower crown facet. The crown in case of a deeper pavilion will need to be shallower to compensate for this.

The crown’s shallow end will have much better light action as there will not be any leakages from the diamond. It will also affect how the diamond will exhibit its fire. This will also affect the dispersion. a

Dispersion is when light enters the diamond and separates into all of its seven colors and then leaves through the top of the stone due to refraction. With a smaller crown light will have less dispersion.

The ideal angle for the crown is 34.5 degrees. Where there are slight variations, the diamond is still able to provide good fire and brilliance. When light enters the diamonds, it will be reflected by the pavilion facts in different ways and this angle is the best for providing an escape to the light.

Also, the light can enter the diamond from multiple locations and still find a great escape. This is the angle where the dispersion is at its optimum.

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