The round brilliant diamond is the most popular diamond shape and, because of the laws of supply and demand, is the generally the most expensive.
Round brilliants make up the vast majority of diamonds found in engagement rings. Round brilliant diamonds are also popular as stud earrings and in pendants. This shape has set the standard for all other diamond shapes, and accounts for more than 75% of diamonds sold today.
There are 58 facets in a Round Brilliant Cut including the culet. On the Crown or upper part of the Diamond, these consist of 1 table facet, 8 bezel facets, 8 star facets, and 16 upper girdle facets for a total of 33. On the pavilion, or bottom part of the Diamond, there are 16 lower girdle facets, 8 pavilion main facets and 1 culet. If the pavilion comes to a point at the bottom, the diamond does not have a culet.
Princess cut diamonds really are royalty in the diamond world. Princess diamonds, which are one of the square cut diamonds, are the second most popular shape behind round diamonds. And, like the stones that rank slightly above them, princess cut stones are brilliant cut. Princess cuts have a square (sometimes rectangular) shape with pointed corners and up to 76 small facets.
The princess is traditionally a square cut (four sides of equal length). However, many princess cut diamonds are slightly rectangular, though this is often hard to detect. All other things being equal, the more rectangular a princess cut diamond, the lower the price.
Princess cut diamonds also tend to have a slightly lower price-per-carat than round cut diamonds. This is because the four sided pyramid shape of the princess cut diamond is similar to one half of the octahedron rough stone from which a princess diamond is cut. This similarity allows two equally sized princess cut diamonds to be cut from the same rough stone with relatively little waste (roughly 60% of the weight of the original rough stone is retained after cutting). The greater efficiency, or yield, translates to a lower price.
The modified brilliant-cut pear shaped diamond is a combination of a round and a marquise shape, with a tapered point on one end. The diamond is always worn with the narrow end pointing toward the hand of the wearer. Like marquise and oval cuts, the pear shaped diamond comes in a variety of slim to wide cuts, and has the added benefit of making the wearer's fingers appear longer and slimmer.
Ideally, a pear shaped diamond should possess excellent or very good symmetry. The point should line up with the apex of the rounded end. The shoulders and wings (the upper and lower curves on the right and left side of the diamond) should form uniform, symmetrical curves, with no straight edges. The rounded top should not appear narrow or squat, but like a semi-circle. In a misguided effort to add weight to a diamond (by incorporating more of the rough stone in the final cut) cutters may give the diamond added girth near the point or top, giving the diamond a squared off or squatty appearance.
The marquise brilliant takes is name from a legend that the Sun King desired a stone to be polished into the shape of the mouth of the Marquise of Pompadour. The marquise brilliant is a football-shaped modified brilliant. The eye-shaped marquise-cut diamond is a rose by many names such as the “football-shaped diamond”, and the “boat-shaped cut” or the “Navette”. It is adored by those who appreciate a diamond with rich history that highlights glamorous jewelry pieces with distinct fire. As with most fancy shapes, the ultimate shape of the finished diamond is determined by the rough crystal and what parameters it allows.
Marquise diamonds are long and narrow, they can also create the illusion of greater size. Carat for carat, the marquise diamond has one of the largest crown surface areas of any diamond shape, making it a good choice when trying to maximize the perceived size of a diamond. Like the oval diamond, the marquise cut diamond's elongated shape can make the finger of the wearer appear longer and slimmer.
The marquise is usually cut as an adaptation of the 58 facet standard brilliant (33 crown, 25 pavilion), the same as the round brilliant. However, the pavilion can be cut with either 4, 6 or 8 pavilion main facets. The crown cut is sometimes modified in the marquise to form what is called a “French Tip,” where the bezel facet at the point of the stone is eliminated. The length-to-width ratio should be in the 1.75-2.25 range.
The oval’s technical name is “oval modified brilliant,” based upon its shape and modifications of the traditional round brilliant configuration. The oval was invented by Lazare Kaplan in the early 1960’s.
The oval is seen most frequently cut in the standard 58 facet brilliant pattern, but can have a varying number of pavilion main facets ranging from 4, 6 or 8.
oval diamonds are a modified brilliant-cut (like virtually all round cuts). Because the two shapes possess a similar fire and brilliance, the oval is an ideal choice for a customer who likes the look of a round diamond, but wants something more unique. Oval diamonds have the added advantage of an elongated shape, which can create the illusion of greater size. The slender shape can also make the finger of the wearer appear longer and slimmer, an effect often desired.
The radiant cut diamond is a beautifully symmetrical, non-traditional cut, the radiant cut combines the brilliance of a round and the purity of an emerald cut. Trimmed corners give this loose diamond shape versatility to shine in all kinds of jewelry, especially engagement rings. The faceting of a radiant cut gives it a fiery look compared to a princess cut, while maintaining soft, cut corners. Overall you could say that the radiant diamond combines some of the most beloved traits of other popular diamond shapes.
The radiant cut diamond is the first square cut (the second being the princess) to have a complete brilliant-cut facet pattern applied to both the crown and pavilion, creating a vibrant and lively square diamond. the cropped corner square shape of the radiant is a nice bridge between a cushion and a princess cut, and for that reason looks beautiful set with both rounded or square cornered diamonds.
The radiant cut is the name used to describe the cut-cornered, rectangular or square modified brilliant, the technical description on GIA grading reports.
While some radiant cut diamonds have 70 facets (25 on the crown, 8 on the girdle and 37 on the pavilion), the most common facet pattern has 62 facets (25 on crown, 8 on the girdle, and 29 on the pavilion) as illustrated on diagram on the right. The truncated corners help to minimize chipping.
The unique look of the emerald cut diamond is created by the step cuts of its pavilion and its large, open table. Instead of the sparkle of a brilliant-cut, emerald cut diamonds produce a hall-of-mirrors effect, with the interplay of light and dark planes. While less fiery, the long lines and dramatic flashes of light give the emerald cut an elegant appeal. The shape was originally developed for the cutting of emeralds, thus the name.
The emerald cut is not a brilliant cut, but is called a step cut which means it has rows of facets. Step cuts are comprised of larger facets which act like mirrors and resemble a staircase, hence the name step-cut.
The emerald cut has 58 facets (25 crown, 8 girdle and 25 pavilion). Because of the angle, size and shape of the facets, the emerald cut shows less brilliance and fire (dispersion) than the other brilliant cut diamonds. However, the emerald cut stone reveals a classic beauty and elegance not seen in other cuts. The look of an emerald cut diamond is subtle and understated with less “flash,” or reflection and refraction than brilliant cuts.
Heart Cut Diamonds:
The technical name for this stone is the “Heart-Shaped Modified Brilliant,” based upon its shape and modifications of the traditional round brilliant configuration.
The heart shape is a brilliant cut which typically contains 59 facets but that can be modified so that the number of pavilion main facets may be 6, 7, or 8.
The modified brilliant-cut heart shaped diamond is a unique and unmistakable symbol of love. Heart shaped diamonds are very popular in solitaire pendants as well as rings. When choosing a heart, symmetry is a very important characteristic, since it is critical that the two halves of the heart are identical. The cleft (between the two lobes) should be sharp and distinct, and the wings (the sides as they curve down to the point) should have a very slightly rounded shape.
Heart shaped diamonds of less than .60 carats may not be a good choice, as the heart shape is more difficult to perceive in smaller diamonds, especially after they are set in prongs. For smaller hearts, a bezel or three prong setting (one prong on each lobe, one prong at the point) will better preserve the heart shape outline of the diamond after it is set.
The Cushion Cut is a generic name for the Old Mine Cut developed before the turn of the century. The term cushion is often used for colored gemstones cut in this shape.
Traditional cushion cut diamonds return light in a chunkier pattern than modern cuts. Combined with the enlarged culet (which was considered desirable for the pattern created when viewed through the table), this created a distinctive look that is prized today among dealers in antique diamonds
A cushion cut is a square or squarish-rectangular cut with rounded corners and 58 brilliant-style facets that resemble a pillow shape, hence the name. Cushion cuts are a little less brilliant than modern round brilliant diamonds, but are more dispersive (which refers to the separation of white light into spectral colors).
The standards for cushion cut vary more than most other shapes, and personal taste will dictate choice. While generally less brilliant than round brilliant diamonds, cushion cut diamonds often have better fire, which is part of their appeal. Modern cushion cuts tend to have one of three basic pavilion facet patterns. The third pattern has an extra row of facets on the pavilion and is classified by GIA as a "modified" cushion cut. These modified cuts tend to have a "crushed ice" or needle like facet pattern, more similar to a radiant cut than a traditional cushion cut.
The modern asscher cut diamond is similar to a square emerald cut, usually with larger step facets, a higher crown, and a smaller table. This combination often produces more brilliance than the emerald cut. A well cut asscher will appear to have concentric squares as you look down through the table, the result of proper positioning of the pavilion facets underneath. Like the emerald cut, the asscher cut has cropped corners; however, because an asscher is square, the cropped corners give the asscher cut a somewhat octagonal shape. Once mounted in a four prong setting, the diamond maintains its unique shape within a square silhouette.
The Asscher cut is a square cut characterized by a smaller table and larger step facet than an emerald cut. It features dramatic, cut corners. It usually has a high crown and a deeper pavilion than today’s emerald cuts. Because of its high crown and small table, the Asscher cut has more light and fire than an emerald cut.
While square emerald cuts and Asscher cuts are similar in facet patterns, Asschers tend to have a depth of 60% or greater and a smaller table. Asschers typically have the following characteristics:
