Diamonds are available in many different shapes. Diamond shape is often confused with diamond cut. Diamond shape refers to the geometric shape of the stone, whereas cut refers to how well the facets and angles reflect light. It is the diamond cutter’s art to make the most brilliant diamond out of the irregular rough stone. The cutter creates a diamond of the greatest possible size with minimum flaws.
The major diamond shapes are:
Round Brilliant Shaped Diamond
Of all diamond shapes, the most famous is round. More than 75 percent of all diamonds sold today are this shape. The round shape of the diamond is cut so as to reflect maximum light from all facets. A round diamond has 58 facets divided among its crown, girdle and pavilion. Unlike any other diamond shape, there is a precise formula to achieve maximum fire and brilliance in a round diamond. Round diamonds are more expensive than others because of the significant loss of weight that is caused by cutting, and the fact that more workmanship is required for cutting and polishing a round diamond than other shapes.
Princess Shaped Diamond
The princess cut diamond is square in shape with sharp edges. The fire and brilliance of the princess cut diamond is relatively lower than round shaped diamond. The facets are carefully cut so as to ensure maximum brilliance. The princess cut utilizes most of the original content of the rough stone with minimum weight loss.
Princess cut is very popular in solitaire engagement rings. It is often embellished with triangular stones on its sides to create more beauty. The weight of the princess cut diamond is carried in its depth, and percentages of 70 to 78 are not uncommon. As long as the length and width ratio of a princess cut are equal to or less than 1.05 to 1, the diamond will appear square to the observer. Princess cut diamonds have sharp edges, and thus are more easily chipped than other shapes. Therefore, when selecting a setting for a princess cut diamond, make sure that prongs would protect the edges of the diamond.
Radiant Shaped Diamond
Radiant cut is the modified form of square or rectangular cut with cut corners, similar to the emerald cut. It blends the elegance of both emerald and round shaped diamonds. The radiant cut has 70 facets that maximize the effect of color refraction. Because of its design, the weight of a radiant stone is in its depth to maximize brilliance. Depth percentages of 70% to 78% are not uncommon. Length to width ratio of 1.05 to 1 is normal.
Emerald Shaped Diamond
An emerald cut diamond is rectangular in shape with cut corners. It is a step-cut stone, meaning that it has flat planes resembling the steps of a staircase. Inclusions and color are more noticeable in an emerald cut than other shapes. Emerald cut diamonds tend to have broad, dramatic flashes of light from their long cut lines. The emerald shape is more economical than round or square shaped diamonds because of its relative unpopularity as compared to the other two. The length to width ratio of 1.35 to 1 is the most prized for an emerald cut.
Asscher Shaped Diamond
The Asscher cut is a variant of the emerald cut and is created by modern cutting and faceting techniques. Its art deco style combines old world charm with modern techniques of beautifying a stone, and it provides a regal and elegant look to the wearer. The Asscher cut diamond is more or less square in shape with length to width ratio of 1 to1. A length to width ratio of 1.1 to 1 or more is not preferred.
Oval Shaped Diamond
An oval shaped diamond is elliptical in shape and is a slight variation of the round diamond shape. A ring set with an oval shaped diamond gives the illusion of longer fingers. Length to width ratio of the oval cut is 1.40 to 1.60. For a rounder shape, the length to width ratio is closer to 1.15 to 1, and for a more elongated shape it is 1.70 to 1.
Marquise Shaped Diamond
The marquise cut is shaped somewhat like a canoe. It is elongated and has pointed ends. It is said that the shape was inspired by the smile of the Marquise de Pompadour. Sun King Louis XIV, who wanted a diamond to match the quality of the Marquise’s smile, commissioned the shape. Rings with marquise cut diamonds create the illusion of longer, narrower fingers. This stone fits well with solitaire settings and looks excellent when enhanced with smaller diamonds. The normal length to width ratio of a marquise cut is 2 to 1, but those who would rather have a more rounded shape prefer 1.5 to 1 and those who would like an elongated shape favor 2.25 to 1.
Pear Shaped Diamond
The pear cut diamond has a teardrop shape and is a combination of round, oval and marquise cuts. It also has the excellent features of a round brilliant diamond. Most of the largest stones discovered throughout history have been cut and faceted to pear shape. Length to width ratio of pear shape diamond is 1.65 to1. A more elongated pear shape has the ratio of 1.80 to 1 and a compact look has the ratio of 1.20 to 1.
Heart Shaped Diamond
The heart, considered the ultimate symbol of love, is nicely presented in a heart shaped diamond. This shape is a unique combination of round brilliant and pear shaped diamonds with a cleft at the top. The skill of the cutter determines the beauty of the stone. The heart shaped stone is usually proportioned in equal length and width. The length to width ratio of 0.90 to 1 and 1.15 to 1 are also acceptable. Ratios below 0.80 to 1 or exceeding 1.20 to 1 are not preferable.
Triangle or Trillion Shaped Diamond
A trillion shaped diamond is triangular with pointed corners. It has the brilliance of a round diamond. The shape and design of the triangle diamond depends on the natural character of the uncut diamond as well as the cutter’s personal preferences. The triangle shaped diamond was first designed in Amsterdam, and has 25 facets on the crown, 19 facets on the pavilion and a polished girdle. Triangle shaped diamonds are also available in a more rounded triangular shape. They are often used as accents in three stone rings and other jewelry settings or combined with other diamonds in solitaire engagement rings.
Cushion Shaped Diamond
The cushion cut is an antique style of diamond that combines the Old Mine Cut and modern oval cut. This cut was common in the late 19th and early 20th centuries when diamonds had deep cuts with large facets. They were also known as pillow cut or candlelight diamonds. This diamond is not as brilliant as newer cuts, but have a romantic and classic look that is unique.
New Diamond Shapes
New, innovative styles and cuts are being created all the time by creative and talented diamond cutters who transform diamonds into unique shapes such as flowers, clover leaves, kites, and so on. Each new style is inspired by the natural crystal formations of the uncut stones.