JewelryOwn

Stone Cut and Shape

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Asscher Cut

This elegant shape is a variation on a classic emerald cut, developed in 1902 by the venerable Asscher brothers in Holland. The Asscher cut is not a traditional choice but has gained deserved exposure recently because of celebrities wearing the cut. The uniqueness of this shape is defined by the pavilion, or bottom part of the diamond, that has a "scissor cut" with all facets step-cut down toward the culet, or point on the bottom. The blocked corners add to its geometric appeal, making the diamond appear almost octagonal. It is usually cut to a square outline as opposed to rectangular. This diamond shape is beautiful in a simple solitaire or in a setting that has simple geometric lines or side stones such as baguettes. Ideally, the setting for an Asscher cut should not hide the unique blocked corners.

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Cushion Cut

The cushion cut is an unusual diamond shape and an interesting alternative to an oval- or princess-cut diamond. Because these are relatively rare, this shape is for someone who wants something few people possess. The modern cushion shape is based on an antique cushion cut, which is a combination of round and square outline with a softened square or "pillow" shape. A cushion-cut may be squarer with length and width in equal proportion, or may have a slightly elongated outline, depending on the individual stone and the wearer's preference. As a solitaire, it makes a statement and also looks wonderful paired with side stones such as baguettes. A cushion-cut diamond setting should have at least four secure prongs.

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Emerald Cut

The emerald-cut diamond is among the most classic of diamond shapes. Its clean lines come from step-cutting, or parallel line facets. It is always cut with blocked corners and is usually cut to a rectangular outline, although a few are cut to be more square. Because of its simpler faceting structure, larger inclusions are sometimes more visible to the unaided eye, so diamonds cut in this shape usually need to be higher clarity (I1 or I2 clarities should probably be avoided). Length-to-width ratios should be considered when choosing an emerald cut: Usually a 1.50:1.00 ratio is preferred, meaning that the length of the stone should be about 1½ times the width of the diamond. However, like all fancy shapes, personal preference prevails, and some may prefer a squarer outline, or longer, thinner rectangle. An emerald cut is loved by purists and looks especially wonderful set in platinum, in a simple setting or a baguette side-stone setting.

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Heart Cut

The heart-shaped diamond is the most romantic of diamond shapes. It is similar to the pear shape but has a cleft in the rounded end that forms the lobes of the heart. The complexity of the shape requires skilled cutting to ensure proper brilliance. Symmetry is a big consideration for this shape, as the outline needs to have a pleasing, obvious heart outline apparent in the setting. The lobes should be rounded (not pointed) and clearly defined. Heart-shaped diamonds should be mounted in special settings with five prongs: two at the lobes of the heart, two on the sides of the heart, and a V-shaped prong to protect the point of the heart, the most vulnerable place on the diamond.

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Marquise Cut

The marquise cut is a regal, elongated shape with tapering points at both ends. Its shape tends to flatter the finger, making it appear longer. When choosing a marquise cut, the length-to-width ratio should be considered. Usually a ratio of 2:1.0 is preferred, meaning that the length of the stone should be about 2 times the width of the diamond. However, like all fancy shapes, personal preference prevails, and some may prefer a shorter, wider outline or longer, thinner shape. Just look for good symmetry to ensure overall beauty no matter what outline you prefer. This shape works in a simple solitaire setting or looks beautiful with side stones, especially baguette or trillion shapes. A marquise-cut diamond should be mounted with six prongs: four positioned on the sides to hold the body of the stone securely and two V-shaped prongs to protect the points at either end, the most vulnerable part of the diamond.

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Oval Cut

The oval cut is most similar a round-brilliant cut and combines the round's sparkle with a flattering, elongated outline. It makes a good choice for someone who wants a unique shape but loves the fire and brilliance of a round diamond. The length-to-width ratio of ovals can vary based on personal preference. Generally a ratio of 1.5:1.0 is preferred, meaning that the length of the stone should be about 1½ times the width of the diamond. However, like all fancy shapes, personal choice should guide you; some may prefer a shorter, wider outline or a longer, thinner shape. The relatively symmetrical shape lends itself well to a variety of mounting styles. Most oval cuts look great in any mounting meant for a round brilliant as long as the setting that holds the diamond has six prongs properly spaced for security.

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Pear Cut

The pear shape is a beautiful, feminine diamond shape with a rounded end on one side and a tapering point at the other. It is lovely as the center stone in a ring or outstanding as a pendant or pair of drop earrings. As with many fancy shapes, length-to-width ratio should be considered. Usually a ratio of 1.5:1.0 is preferred, meaning that the length of the stone should be about 1½ times the width of the diamond. Some may prefer a shorter, wider outline or a longer, thinner shape. Good symmetry is a must for pear-cut diamonds. This will ensure that light is reflected evenly, especially in the point. The asymmetrical shape should be considered when setting a pear cut, which looks beautiful as a solitaire, or with side stones, especially smaller pear-cut stones or baguettes. A pear-shaped diamond should be mounted in a special setting with five prongs: two to hold the rounded end, two to hold the curved sides of the stone securely, and one V-shaped prong to protect the point at the other end, the most vulnerable part of the diamond.

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Princess Cut

The princess cut is a modern classic of clean, square lines and beautiful sparkle. This shape is the perfect choice if you prefer a square or rectangular outline but want the brilliance of a round. Developed in the 1970s, the princess cut is now second only to the round brilliant in popularity. The cutting of this diamond combines the step-cutting of the emerald cut with the triangular facets of the brilliant cut and is cut with right-angle corners. Although most prefer a square outline, some stones are cut with a slightly more rectangular outline. The princess cut works beautifully as a solitaire but also looks great paired with side stones, especially trillions or smaller princess-cut diamonds. It is important to protect the more vulnerable corners with a V-shaped prong at each point.

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Radiant Cut

The radiant cut is a beautiful combination of the classic emerald cut and the sparkle of the round brilliant. The radiant cut is similar to the princess cut but is usually (though not always) a more rectangular outline and has blocked corners like those of an emerald cut. The cutting is a combination of the step-cutting of the emerald-cut diamond with some triangular faceting of the brilliant cut. The radiant cut is dramatic as a solitaire but also looks great paired with side stones such as baguettes, trillions, or princess shapes. A radiant-cut stone should be set with special prongs to hold the blocked corners securely.

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Round Cut

By far the most preferred diamond shape, the round-brilliant cut is also the most optically brilliant because of its 360-degree symmetrical shape. A round brilliant is a great choice if you want the most sparkle and the most enduring classic shape. The round shape has been cut for centuries, but in 1919, Marcel Tolkowsky defined specific angles and proportions to yield the most brilliant diamond, which form the basis for the modern "Ideal" cut round-brilliant diamond. Round-brilliant diamonds are the only shape to have this ideal proportion defined. The round silhouette works with almost every mounting, from classic solitaires to the most avant-garde designs. Rounds can be set into four or six prongs, based on the design of the setting, or into bezel mountings (a metal band that runs around the edge of the diamond to hold it securely in the setting). In general, if the round brilliant has an Ideal cut or Very Good cut, you want the setting to have the least amount of metal around the stone so that it is held securely but does not cover up too much of the diamond and block light from entering the stone.

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Trillion Cut

The trillion cut is a dramatic cut that makes a bold statement. It was developed in the 1970s as a variation of the radiant cut, combining step-cutting and brilliant faceting. While often used as side stones, this cut is rarely used for the center diamond, so it is somewhat scarce in larger sizes. The triangular shape needs to be considered with the style of mounting and would probably go best in a simple solitaire or geometric setting that works with the unique shape. The trillion cut will require a special setting that has V-shaped-prongs to protect the corners of the diamond.

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Most gemologists will agree that, of all the four C’s, cut is the most important. The cut of a diamond influences the way it reflects light, which in turn determines its brilliance. Even a diamond with perfect color and clarity may appear lifeless if it does not have a good cut.

In a well-cut diamond, light enters the stone and is reflected around the mirror-like facets before exiting through the top, or table. This careful orchestration of the movement of light inside the stone and back to the eye is what causes the fiery sparkle we recognize as brilliance. A skilled professional can maximize this effect by cutting a diamond to very precise proportions. Too shallow a cut will allow light to escape through the bottom of the stone, causing it to look dull. Too deep a cut will cause light to be lost through the diamond’s sides, making it appear dark.

Depth is not the only important factor; other angles and proportions matter as well. In fact diamond cutters now use sophisticated computer modeling tools to give them a full picture of how light will behave inside a stone, allowing them to adjust proportions to optimize a diamond’s brilliance, as well as its brightness, scintillation, and fire, the qualities known collectively as the diamond’s “face-up appearance.”

Some round diamonds come with certifications that supply their cut grade. The GIA (Gemological Institute of America) ranks diamonds as Excellent, Very Good, Good, or Fair. The AGS (American Gem Society) ranks them as Ideal, Excellent, Very Good, Good, or Fair. Amazon represents both Round GIA “Excellent cut” diamonds and Round AGS “Ideal cut” diamonds as “Ideal” on our site, since these two terms both refer to the highest quality of diamond cut.

Round cut diamonds, it should be noted, are the only ones that can achieve a grading of “Ideal.” Other cuts, such as Princess, Asscher, or Emerald, will receive, at the highest, a grading of “Very Good.” For diamonds that do not have AGS or GIA certifications, Amazon will calculate the cut based on the stone’s depth, table percentages, symmetry and polish.

• Ideal
  A diamond described as Ideal represents the highest standards of cut, with only the top 3% of all diamonds falling in this category. An Ideal Cut diamond reflects nearly all the light that enters it and displays maximum brilliance and fire. For those who want the very best that money can buy, this is the cut to choose.


• Very Good
  A diamond described as Very Good reflects nearly as much light as an Ideal cut diamond, and represents approximately the top 15% of diamonds based on cut. The proportions may overlap with many of the proportions of an Ideal cut, with slight variations from the preferred range that allow the cutter to create a larger stone. A diamond with a Very Good cut has exceptional brilliance and is generally priced slightly lower than an Ideal cut diamond.


• Good
  A diamond described as Good reflects most of the light that enters it, and is much less expensive than a Very Good cut. A diamond in this category represents roughly the top 25% of diamonds based on cut. Its proportions may vary from the preferred range because the cutter has opted to maximize the size of the stone rather than creating a smaller Very Good quality diamond. For those shopping on a budget, a diamond in this range offers good quality and excellent value.


• Fair
  A diamond described as Fair represents the top 35% of diamonds based on cut. Though it is still a quality cut, it reflects less light and displays less brilliance than a Good Cut diamond. Diamonds in this range are typically cut to maximize size over other factors.