SHAPE

Virtually all diamond shapes sold for use in jewellery are one of these ten diamond shapes:

Shape has an important determinant on the price of a diamond – as yields of polished weight from a rough diamond vary depending on the shape. Round is most expensive as it is has the lowest yields compared to all other shapes. Next lowest yield is of the pear shape and hence the next most expensive. Below is table of all major shapes and approximate relative pricing:

ROUND

The round cut diamond is the most popular diamond shape.  Virtually all round diamonds are Brilliant cut, meaning they have 58 facets (57 when there is no culet).

Round diamonds cost more on a per carat basis than fancy shapes because its yield from the rough is relatively low. Because more of the rough stone is lost in the cutting of a round diamond. A typical round diamond (for example; a 1.00 carat, F-color, VS2-clarity, Ex cut) may cost 25-35% more than a similar fancy shape.

PRINCESS

The princess cut diamond, first created in 1980 by Betzalel Ambar and Israel Itzkowitz, is the most popular fancy cut, especially for engagement rings. The princess has pointed corners and is traditionally square in shape.

Princess cut diamonds have a slightly lower price-per-carat than round cut diamonds due to greater yield from the rough.

Also, princess-cut diamonds can vary greatly in how square or rectangular they are. The length-to-width ratio will determine what the diamond will look like when viewing it from above. Here are length-to-width ratios for princess-cut diamond shapes:

Princess shape diamonds Length to Width Ratios

For a princess diamond shape that is square, look for length-to-width ratios between 1 and 1.05. If you prefer more of a rectangular shape, look for length-to-width ratios greater than 1.10.

A princess cut diamond should always be set with prongs that protect the four corners (the most likely location for chipping). Most other square cuts (such as emerald, asscher, and radiant) have cropped corners.

Of all of the square cuts, the brilliant-cut princess (along with the radiant cut) comes the closest to achieving the fire and brilliance of a round diamond, making it an ideal combination of unique shape, sparkling appearance, and relative price value.

PEAR

The modified brilliant-cut pear shaped diamond is drop shaped diamond, with a tapered point on one end. Ideally, a pear shaped diamond should possess excellent or very good symmetry.

The length-to-width ratio will determine what the diamond will look like when viewing it from above. Here are length-to-width ratios for pear-cut diamond shapes:

Pear shape diamonds Length to Width Ratios

While the length to width ratio of classic pear shaped diamonds is 1.40-1.70, personal preference will again dictate choice. The shape preference may also be affected by the diamond's eventual setting: A narrow pear diamond is ideal for dangle earrings, while a wider shape might be preferred for a solitaire ring.

Pear shaped diamonds possess some degree of bow-tie, varying from near invisible to severe. The visibility of a bow-tie effect cannot be ascertained by reviewing the diamond certificate or dimensions, but only upon visual inspection or microscopic image.

A pear diamond should always be set with a prong at the point - the most likely location for chipping on a pear cut diamond.

EMERALD

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. While less fiery, the long lines and dramatic flashes of light give the emerald cut an elegant appeal.

The length-to-width ratio will determine what the diamond will look like when viewing it from above. Here are length-to-width ratios for emerald-cut diamond shapes:

Emerald shape diamonds Length to Width Ratios

Emerald cut diamonds vary from nearly square to a narrow rectangle. The classic emerald cut diamond has a length to width ratio of around 1.50. If you prefer the look of the square emerald cut diamond, be sure to consider the asscher cut as well (which has a very similar appearance, and is defined by GIA as a square cut emerald).

Due to its larger, open table, this shape highlights the clarity of a diamond. If you choose an emerald-cut with a lower clarity grade, such as SI, be sure to review the clarity in the microscopic picture or by visual inspection.                                                             

HEART

The modified brilliant-cut heart shaped diamond is a unique and unmistakable symbol of love. When choosing a heart, symmetry is a very important characteristic, since it is critical that the two halves of the heart are identical.

The length-to-width ratio will determine what the diamond will look like when viewing it from above. Here are length-to-width ratios for heart shape diamonds:

Heart shape diamonds Length to Width Ratios

The length to width ratio of a classic heart shaped diamond is approximately 1.00, personal preference will dictate choice. For hearts that are to be set in pendants, buyers may prefer a slightly narrow cut (1.05 - 1.15), while for hearts set in a solitaire ring, a slightly wide cut (0.85 - 1.00) may be most appealing.

OVAL

Created by Lazare Kaplan in the 1960's, oval diamonds are a modified brilliant-cut. Oval shape diamonds possess a similar fire and brilliance to round shape diamond. 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 length-to-width ratio will determine what the diamond will look like when viewing it from above. Here are length-to-width ratios for oval cut diamonds:

Oval Diamond Length to Width Ratios

Preferences vary on how narrow or fat an oval cut diamond should be, so choose what appeals to you personally (though a length to width ratio of 1.35 - 1.50 is considered the classic oval cut). A slightly thinner cut may look most appealing in a setting where the diamond is flanked by side stones.

Oval cut diamonds possess some degree of bow-tie, varying from near invisible to severe. The visibility of a bow-tie effect cannot be ascertained by reviewing the diamond certificate or dimensions, but only upon visual inspection or by viewing the microscopic image.

MARQUISE

The marquise diamonds are a modified brilliant-cut. The name is derived from the Marquise of Pompadour, for whom King Louis XIV of France allegedly had a stone fashioned to resemble what he considered her perfectly shaped mouth. Because 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.

The length-to-width ratio will determine what the diamond will look like when viewing it from above. Here are length-to-width ratios for Marquise-cut diamond shapes:

Marquise shape diamonds Length to Width Ratios

Personal preference should dictate how narrow or fat a marquise diamond you choose, although a length to width ratio of 1.75 -2.15 is considered the classic marquise cut

Symmetry is very important in marquise cuts. The two end points should align with each other, and the right and left sides should form a near mirror image. For this reason, excellent or very good symmetry is strongly recommended.

A marquise diamond should always be set with prongs to protect the two points (the most likely location for chipping).

Marquise cut diamonds possess some degree of bow-tie, varying from near invisible to severe. The visibility of a bow-tie effect cannot be ascertained by reviewing the diamond certificate or dimensions, but only upon visual inspection or viewing the microscopic image.

CUSHION

The cushion cut diamond combines a square cut with rounded corners, much like a pillow (hence the name). This classic cut has been around for almost 200 years, and for the first century of its existence was the most popular diamond shape (similar to round cut today).

Many buyers are attracted to the antique feel combined with modern performance offered by the cushion cut. While generally less brilliant than round brilliant diamonds, cushion cut diamonds often have better fire, which is part of their appeal.

The length-to-width ratio will determine what the diamond will look like when viewing it from above. Here are length-to-width ratios for cushion shape diamonds:

Cushion shape diamonds Length to Width Ratios

While the classic cushion cut diamond is a square (with a length to width ratio of 1.00), they are often found in slightly rectangular shapes as well. The most popular shape is a slight rectangle of 1.10-1.20 length to width, however personal preference should dictate choice.

RADIANT

The radiant cut diamond is square shaped with cropped corners, having a complete brilliant-cut facet pattern.

The length-to-width ratio will determine what the diamond will look like when viewing it from above. Here are length-to-width ratios for radiant shape diamonds:

Radiant shape diamonds Length to Width Ratios

There are diverse preferences when it comes to shape in radiant cut diamonds, from a perfectly square 1.00 length to width ratio, to a more traditional rectangle. The rectangular radiant cut is an excellent option for buyers who like the emerald cut shape, but want something with the brilliance of a round. The square radiant looks very similar to a princess cut, but with cropped corners. Once set, a square radiant and a princess look virtually identical, since the prongs cover the corners.

In longer (more rectangular) radiant cut diamonds, a bow-tie effect is more likely (although not as common as in oval, marquise, and pear cuts), varying from near invisible to severe. The visibility of a bow-tie effect cannot be ascertained by reviewing the diamond certificate or dimensions, but only upon visual inspection or viewing the microscopic image.

ASSCHER

The asscher cut diamond was first produced in 1902 by the Asscher Brothers of Holland, famous at the time for cutting the world's largest rough diamond (the Cullinan, at 3,106 carats). The asscher cut diamond can also be called a square emerald, as they represent the same cut.

Ascher shape diamonds Length to Width Ratios

The classic asscher cut diamond is a square (with a length to width ratio of 1.00). Any ratio of 1.05 or less will appear square to the naked eye

Due to its larger, open table, this shape highlights the clarity of a diamond. If you choose an asscher-cut diamond with a lower clarity grade, such as SI, be sure to review the clarity in the microscopic picture or by visual inspection.

Buying Tip

Selection of shape is a matter of personal preference.  Round is by far the most popular, preferred and standardized among all shapes. But if you are looking for variety and uniqueness, select a fancy shape. Also remember that the fancy shapes will cost you less than rounds.