Executive summary
The outline of the diamond when it is viewed from the top through to the bottom of the diamond is referred to as the shape of the diamond. There are different types of diamond shapes. But the most common ones are round, pear, oval, princess, marquise, cushion, emerald, heart, radiant and Asscher diamond shapes.
Round diamonds: It is the most common diamond shape even if it is also one of the most expensive. It is a brilliant diamond. When cut to ideal proportions, it exhibits so much brilliance, it is difficult to see color and inclusions in it.
Princess diamond: It is a fancy diamond used mainly for engagement. They are similar to round cut in the sense that they are very flexible, also very expensive and can be used with any style and setting. It is square or rectangular shaped and the edges are prone to chipping and inclusions.
Oval diamond: It is also a brilliant-cut diamond and this allows it to mask impurities in it. But it is also very susceptible to the bowtie effect. You should pay attention to the setting before buying an oval diamond.
Marquise diamond: The two points of the diamond are prone to chipping and inclusions, so the setting must contain two prongs to protect and cover these two points. Symmetry is extremely important to this diamond.
Pear diamond: Combination of round and marquise diamond. Modified brilliant diamond with a variety of shapes based on the LW ratio.
Cushion diamond: They have 3 patterns of pavilion facets. Shows more fire than the round diamond but it is not as brilliant.
Emerald diamond: Step cut diamond with a lot of brilliance. It has both rectangular and square shapes (which resemble Asscher diamonds).
Asscher diamond: Looks very much like the emerald diamond but with cropped corners which gives it its octagonal shape.
Radiant diamond: A brilliant square-cut diamond that can come in two shapes; square or rectangle.
Heart diamond: Symmetry is very important. It comes in the shape of “love”. The setting should have 3 prongs (one on each lobe and one at the point).
The shape of a diamond refers to the outline of the diamond when it is viewed from the top through to the bottom of the diamond. It is a diamond property that is usually confused with the cut of the diamond but is different from a diamond cut. There are different types of diamond shapes. But the most common ones are round, pear, oval, princess, marquise, cushion, emerald, heart, radiant and Asscher diamond shapes.
Round Cut Diamond
This is the most common of all diamond shapes. It accounts for up to 75% of all the diamonds sold in the market. Round diamonds are known to be brilliant cuts and are therefore able to maximize their brightness. The number of facets that they have is 58 (is 57 when the culet is absent). The round diamond is one of the most expensive diamond shapes, if not the most expensive (more expensive than fancy diamonds). The reason is first, the fact that when cutting the diamond, a large part of the rough stone is lost in the process. This is the reason why they are more expensive on a per-carat basis. Secondly, they are also the most sought after diamond in the market. So their high demand couple with their low yield is why they are usually expensive.
Marcel Tolkowsky’s work in 1919 (which marked the beginning of this diamond’s popularity) helped to describe the ideal proportions for a round cut diamond to maximize the light that enters it for its brilliance and fire. The original specifications made by Tolkowsky is 53% table, 34.50 crown angle, 59.3% depth, and a visible culet. But these specifications have been modified down the years. These theoretical advancements coupled with technological advancements have helped diamond manufacturers improve their brilliance.
The level of brilliance that the round diamond exudes helps to cover any inclusions that are in them, making them less visible. This means that you can buy a round diamond with a slightly lower clarity grade like the VS2 or SI1 and it would still give a perfectly brilliant display. Their brilliance also means that they can go well with any setting or style.
The brilliance of the round diamond makes it very difficult to see any color in the diamond. So if you have a well-cut round diamond, you can go down on the color scale as low as J or K because of the diamond’s brilliance masks the color in it.
Princess Cut Diamond
This shape was created by Israel Itzkowitz and Betzalel Ambar in 1980. It is a popular fancy cut that is especially used for engagement rings. They are similar to round cut in the sense that they are very flexible and can be used with any style and setting.
Princess cut diamonds are also a very expensive diamond cut just like the round cut diamonds but their price per carat is lower in comparison to round cut diamonds. The shape of the diamond is the reason for this. The pyramid shape of this diamond cut and ½ of the octahedron rough stone, which is where the diamond is cut from, are actually similar. This similarity between them makes it possible to cut two different (equal) princess cut diamonds from one octahedron rough stone. This reduces the amount of wasted rough stone. About 60% of the original octahedron rough stone is used in this process, unlike with a round cut diamond where there’s a lot of waste and less yield. The increased yield of the princess diamond translates to a relatively lower price than the round diamond.
The princess diamond is normally a square cut (meaning that they have 4 equal sides). But there are also princess diamonds that have a rectangular shape. This depends on the length to width ratio of the diamond. The ideal length to width ratio of this diamond is 1.05, princess diamonds with this length to width ratio or lower will be square while those higher than this figure appears rectangular as the length to width ratio increases. Ideally, the more rectangular a princess diamond is, the lower the price.
The four corners of the princess diamond are quite prone to chipping and inclusions. This is because they were closer to the edge of the octahedron rough stone. This is why it is necessary that the setting that you chose to place the diamond in has to have prongs at the corners/edges, in order to protect it. These prongs cover the likely inclusions and chipping that may be at those edges so they do not affect the overall appearance of the diamond.
When it comes to brilliance and fire, the princess cut diamond is the one that comes closest to the round cut diamond amongst the square-cut diamonds.
Oval Cut Diamond
The oval diamond is a brilliant-cut diamond that was created in the 1960s by Lazare Kaplan. They look quite similar to the round cut diamond especially with the brilliance and fire which they also have. Unlike the round diamond, the oval diamond is more elongated and this makes it appear longer than it actually is in reality. The thin shape of the diamond means that it also makes the finger of the wearer appear thinner and longer and this is something that a lot of people love.
Depending on your preference, you can have a slimmer and longer oval diamond or a wider and squatter oval diamond. This shape variation is determined by the length to width ratio of the individual oval diamond. The ideal length to width ratio is between 1.35 – 1.50. If you want your diamond wider and squatter, the length to width ratio will be lesser than 1.35 but if you prefer it to be thinner and longer, the length to width ratio will be more than 1.50. Your choice of setting may also influence if you go for a classic, thinner or a wider oval diamond. The thinner oval diamond is more appealing in a setting with side stones flanking the main diamond.
The bowtie effect is something that you must look out for in an oval diamond. Oval diamonds usually have a bowtie effect but to varying degrees. It may be nearly invisible in some while it is severe in others. You must ensure that you check and inspect a diamond and ensure with your eyes that it does not have the bowtie effect. The only way to do this is by physical and visual inspection. By merely looking at the diamond certificate, you would not be able to ascertain whether or not a diamond has the bowtie effect and its severity in the diamond if present. That is why it is important to inspect it physically first.
The brilliance and fire of this diamond-cut make it possible for the diamond to mask impurities in it. This allows you to go further down the clarity scale to SI1 or even SI2.
Your choice of setting can determine what color grade to buy when considering the oval diamond. If you are setting the diamond in a silver-hued metal, platinum or white gold setting, the H grade is more ideal. But if you are setting it in a yellow or rose gold setting, you can afford to go further down the color grade to I or even K.
Marquise Cut Diamond
The marquise diamond is a brilliant-cut diamond-shaped like a football. It got its name after King Louis XIV of France ordered that a diamond be cut to resemble the perfectly shaped lips of the Marquise of Pompadour. The marquise cut is also a long and narrow diamond shape so they also have the ability to create the illusion that they are actually bigger than they really are.
The crown surface area of the marquise diamond is considered one of the biggest of the different diamond shapes when compared on a carat for carat basis. So they are a perfect choice for diamond buyers who might want to try to maximize how people perceive the size of their diamond. Just like the oval diamond, the marquise diamond can also take longer and slimmer, the fingers of whoever is putting them on.
They also possess some degrees of bowtie effect, so you must check visually to confirm before committing yourself to buy it.
The length to width ratio may vary among marquise diamonds. Depending on what your preference is, you can settle for length to width ratio of 2.5 and above if you like it narrow. If you like it fast, you can settle for length to width ratio below 1.75. But the classic length to width ratio for marquise diamonds is from 1.75 – 2.15.
For marquise diamonds, symmetry is very important. Both sides must be mirror images of each other. The two endpoints of the diamond must align perfectly. A slight misalignment with the point can destroy the overall outlook of the diamond. The symmetry rating for this diamond must be at least very good.
The two points of the diamond are prone to chipping and inclusions, so the setting must contain two prongs to protect and cover these two points.
Pear Cut Diamond
The pear-shaped diamond is a modified brilliant-cut that is a combination of the marquise diamond and the round shape diamond. The diamond has one end which is tapered. The diamond is usually worn such that this narrow tapered end is pointing directly towards the wearer’s hand. Very much like the oval and marquise diamonds, the pear diamond can also create the illusion of a longer and slimmer finger for the wearer.
This diamond also comes with its own variety of classic, slim and fat pear diamonds based on the length to width ratio of the individual diamond. The classic pear diamond has a length to width ratio of 1.50. The thinner pear diamond has a length to width ratio of 1.60 and above. While the fat pear diamond has a length to width ratio of 1.40 and below that. The preferred eventual setting of the diamond will also determine what shape you will choose. The wider pear diamond is ideal for the solitaire ring but the narrow pear diamond is not but rather with for a dangle earring.
Whatever setting that you decide to go with, you must ensure that the narrow tapered point is covered with a prong. That point is where you’re more likely to encounter inclusions because it was closer to the rough stone’s outer edge. It is also the part that is most susceptible to chipping. That’s why it has to be covered. Once it is covered, the flaw would not be visible to others except it is significant enough to disturb the overall outlook of the diamond (which happens very rarely).
Your preferred setting can also play a role in the color grade which you decide to buy to help you maximize cost. If you are using white gold, platinum solitaire, or halo settings (with stone at the sides), G – H are ideal color grades. But if you are using rose gold or yellow gold setting, you can afford to go further down the clarity grade to grade J and the diamond will still appear white in this setting.
Cushion Cut Diamond
The cushion cut diamond (formerly known as old mine cut) is a square cut diamond with round corners. It looks very much like a pillow, that’s why it is called a cushion cut. This diamond shape has been in existence for about 200 years of its existence and was the most popular diamond shape in the first 100 years of its existence. The earlier traditional cushion diamond reflected light in a very different chunkier pattern than the more recent cushion diamonds. The recent cushion diamonds have an enlarged culet which is useful to create the desired pattern when viewed from the top of the table. This pattern creates a very distinct look that is loved in the cushion diamond by buyers and sellers of antique diamonds.
The refinement of cushion diamonds started in 1920 after Marcel Tolkowsky’s work. These modifications (such as improving the cut angles to maximize the diamond’s brilliance, enlargement of the table and shrinking of the culet) that have happened over the years have caused the popularity of the cushion diamond to increase down the years.
The classic cushion diamond is a square shape with a length to width ratio of 1.00 but there are some cushion diamonds with a slightly rectangular shape. The most popular ones usually have a length to width ratio of 1.10-1.20. Your choice of shape would depend on your personal preference.
There is a lot of variation of the cushion diamond but generally, they tend to have more fire than the round cut diamond (which is something that makes them very appealing) but they are not as brilliant as the round cut diamonds.
The modern cushion diamonds has 3 patterns of basic pavilion facets. They tend to show a needle-like facet pattern or a crushed ice pattern which makes them look very similar to radiant cut than the traditional cushion cut.
To save some money on diamond color, you can settle for a cushion diamond of grade H – J if you are placing the diamond in a white gold setting. But if you are setting the diamond in rose gold or yellow gold setting, you can also settle for a diamond color grade of I – J.
Emerald Cut Diamond
The emerald diamond is a step-cut diamond with a unique look created by its pavilion and large, open table of the diamond. Unlike many other diamonds, the emerald diamond does not show the sparkle that the brilliant diamonds possess, rather, it produces what is known as the hall-of-mirrors effect. There is usually an interplay of dark planes with white planes in this effect. Although not so fiery, the long lines and the flashes of light which the emerald diamond shows make it a very appealing diamond cut. This cut was originally created for cutting the gemstone emerald. That’s why it is a so-called emerald cut.
There are 2 different variations of the emerald diamond. There’s the nearly square emerald diamond and the nearly rectangular emerald diamond. The classic emerald cut is a nearly rectangular emerald diamond with a length to width ratio of 1.40 – 1.50. If you like your emerald diamond to appear more rectangular, you can an emerald diamond with a higher length to width ratio (> 1.60) but if you prefer the nearly square emerald diamond, you have to settle for a length to width ratio of about 1.30.
The square emerald diamond looks very similar to the Asscher cut diamond. So you might also want to check out the Asscher diamond if you have a preference for the square emerald diamond.
Step cut diamonds generally do not show a lot of brilliance, so they are unable to mask the colors in them well enough as the brilliant diamonds do. This makes it very important for the buyer to pay a lot of attention to the color of the diamond when buying an emerald diamond.
Asscher Cut Diamond
This diamond cut was developed in 1902 by the famous Asscher brothers of Holland, famous then for cutting the largest rough stone in the world at the time (the Cullinan with 3106 ct.). This diamond cut became popular in the 1920s. It started to make a comeback in 2002 due to the modifications that were made to the cut. These modifications, over the years, have added more brilliance to the modern Asscher diamonds than the traditional ones. This modern Asscher diamond is very similar in appearance to the square emerald diamonds. The difference is in their smaller table, higher crown and larger step facets. This modified combination in the Asscher diamond makes it more brilliant than the emerald diamonds that show a hall-of-mirrors effect.
When an Asscher diamond is well cut and the pavilion facets are properly positioned, the diamond will appear to have concentric circles as you look through the table of the diamond.
The Asscher cut diamonds, very much like the emerald diamonds, also have cropped corners. The shape of the Asscher diamond is square but the cropped corners which it has gives the diamond an octagonal shape. The ideal setting for the Asscher diamond is a four-prong setting. The unique shape of the diamond is maintained in a four-prong setting within the square silhouette.
The ideal length to width ratio of the classic Asscher diamond is 1.00, with the diamond having a square shape. Asscher diamonds with length to width ratio of 1.05 and below will be square-shaped when viewed with the naked eye. There are however some Asscher diamonds that have a slightly rectangular shape due to their length to width ratio of around 1.08.
The flat table which the Asscher diamond possesses gives an unobstructed view to the center of the diamond making it very easy to see any impurities in the diamond. The clarity of the diamond is, therefore, a very important attribute of the Asscher diamond as it does not have the ability to mask inclusions in it. The size of the diamond also determines if you will see the color in it or not. The bigger the diamond, the easier it is to notice the color in it and vice versa.
Radiant Cut Diamond
The radiant cut diamond, like the princess diamond, is also a square-cut diamond. The pavilion and crown of this diamond have a brilliant-cut facet pattern applied to them. This makes the radiant diamond a very lively and vibrant square diamond. This diamond cut first became popular in the 1980s. The square shape and cropped edges made the radiant diamond appear like a bridge between the princess diamond and the cushion diamond. This makes it beautiful to set the diamond in a square-cornered or round setting and it will still appear beautiful in both.
The rectangular radiant diamond can have the bowtie effect, although it is not very common like in the oval, pear and marquise cut diamonds. The visibility of the bowtie may range from severe to near invisible. It is only by physical inspection that you can ascertain the severity of the bowtie effect in a diamond and not by checking the diamond certificate.
There are different variations to the shape of the radiant diamond. There are radiant diamonds with a perfectly square shape and a length to width ratio of 1.00. Radiant diamonds with a length to width ratio less than 1.05 will also appear square-shaped when you look at them with the naked eye. Other radiant diamonds have a rectangular shape (like the traditional radiant diamond). These rectangular radiant diamonds have a length to width ratio of 1.15 and above.
You can choose either the square or rectangular radiant diamond depending on your preference. The rectangular radiant diamond is perfect for diamond buyers that like the emerald diamond but want a diamond more brilliant than the emerald diamond has to offer.
The square radiant diamond looks very much like the princess diamond with cropped edges. When placed in a 4 prong setting, they look virtually the same, since the corners are covered by the prongs.
Heart Cut Diamond
The heart diamond is a modified brilliant-cut diamond with a unique shape of the symbol of ‘love’. This diamond is very popular as rings and solitaire pendants. One of the most important characteristics of the heart diamond is the symmetry. The two sides of the heart must be equal and identical. The cleft of the diamond (the line that separates the two lobes of the diamond) must be sharp and very distinct. The shape of the wings (the 2 sides of the diamond that curves downwards to the pointed edge of the diamond) should be slightly rounded.
It is harder to perceive the heart shape of this diamond in smaller sized diamonds. That is why it is the wrong decision to buy a heart diamond with a carat weight of less than 0.5 ct. especially if the diamond is set in prongs. The ideal setting for small heart diamonds is the bezel setting or the three-prong setting (with one prong at the point and one on each lobe too). This setting will help to preserve the heart shape of the diamond.
There are different silhouettes of the heart shape, varying from the narrow heart shape to the fat heart. The length to width ratio of the classic heart shape diamond is 1.00. Based on personal preferences, a buyer might decide to buy a slightly narrow heart diamond with a length to width ratio of 1.05 – 1.15 or a wide heart diamond with a length to width ratio of 0.85 – 1.00.
The setting in which you prefer to place the diamond may also determine which heart shape to buy. If you are going to set the heart diamond in a pendant, the more ideal one to buy is the narrow heart. But if your preferred setting is a solitaire ring, then it is more ideal and appealing to buy the wide heart diamond.
