Circular Diamond Shapes
Updated: Oct 12, 2020
In August we laid out the various rectangular shapes that are available for diamonds. This month, we're highlighting the options you have when it comes to circular shapes! The most common shapes are Round, Marquise, Oval, Pear, and Heart.
Over 75% of diamonds sold are round, making this the most popular diamond shape. Everything that is not a round diamond is actually considered a ‘fancy shape.’ Round diamonds also cost more per carat versus fancy shapes. There are two reasons for this; one for being that the demand for round diamonds is very high, and two is that the yield is relatively low. Due to the mechanics of its shape, the round is generally superior to fancy diamond shapes because of the proper reflection of light by maximizing potential brightness.
The shape of a round-cut diamond is made up of 57 or 58 facets (sides), including the culet. The culet is the tiny point at the base of the diamond. In a uniformly cut diamond, the facets should meet at a perfect point – these diamonds will have no culet. When a culet is present, the diamond is referred to as having 58 facets. A typical round cut diamond can cost 25-30% more than a fancy shape.
Length to width ratio: For the most aesthetic diamonds, choose a length to width ratio of 1.0-1.03.
The Marquise shape is named after 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. Marquise diamonds are long and narrow, which can sometimes create the illusion of being greater in 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.
Because of marquise’s sharp corners, this shape can be prone to chipping if not tightly secured by its prongs. It is also important for the two ends of the stone to align perfectly as the tiniest symmetry flaw can affect the balance of the gem when set on a ring. Sometimes, a bow-tie effect may be seen, but if your diamond has excellent proportions, then it will be hidden in the facets’ brilliance.
Much like the oval diamond, a marquise cut diamond's elongated shape can make the finger of the wearer appear longer and slimmer. When purchasing a marquise diamond, buy very good or excellent symmetry as it’s very important.
Length to width ratio of 1.75 -2.15 is considered the classic marquise cut. “Goldilocks range” – diamonds at 1.70 to 1.80 which is just right.
The oval diamond shape was created by Lazare Kaplan in the 1960s. This shape possessed a similar fire and brilliance like the round cut but, appears larger with the same carat weight. Just like marquise, its longer structure appears to elongate the finger. Oval diamond shapes can sometimes create a bow-tie effect too but are usually seen in lengthier ovals. Because of this, it’s best to have the right proportions and to choose a higher color grade since the oval shape is likely to show more color.
Since the round facets in oval hide inclusion so well, you can go as low as an SI2 for this shape with it still being clean to the eye.
An ideal length to width ratio of 1.35 - 1.50 is considered the classic oval cut.
A pear-shaped diamond is almost always worn with the narrow end pointing down toward the wearer. An ideal pear-shaped diamond should have excellent or very good symmetry and should be set with a prong at the point, as it’s the location that most often chips. A modified brilliant-cut pear is a combination of a round and a marquise shape. Much like marquise and oval cuts, the pear-shaped diamond comes in slim to wide cuts making the wearer’s fingers appear longer and slimmer.
The length to width ratio of a classic pear is between 1.4 - 1.7 but its personal choice.
The modified brilliant-cut heart-shaped diamond is the symbol of love. Symmetry is a very important characteristic of the heart-shaped diamond, as it’s critical that the two halves are identical. The cleft between the two lobes need to be sharp and very distinct, and the wings (sides that curve down) should be rounded in shape.
Although the heart shape silhouette is dictated by preference, the classic ratio is 1.00. Since the brilliant-cut stones produce a ton of sparkle, small inclusions can be hidden within the stone. A VS2 or SI1 clarity gems can be flawless and eye-clean.