The form of a diamond - its visual shape.

 

Diamonds are cut into many different shapes. A diamond's shape is often confused with its cut. The "shape" of a diamond refers to its form and its appearance when viewed from above. Some of the most common shapes are shown above and described below. A diamond's "cut" refers to its overall reflective qualities, impacting its briliance and ability to reflect light.

Round Brilliant

This is by far the most popular of all diamond shapes. It is the traditional choice for diamond engagement rings. The round brilliant cut is known to be the most luminous of all the shapes due to the number of facets it has. There are typically 58 facets and 57 facets when there is no cutlet (the "cutlet" is the area at the bottom of a diamond which can be a point or cut into a very small facet). The round brilliant is cut into proportions to achieve the maximum brilliance, providing the most sparkling appearance of all the shapes.

Princess

This is the second most popular cut behind the round brilliant. The princess cut is a brilliant style shape with sharp uncut corners. It is typically cut into a square (four sides of equal length) but may also be slightly rectangular (although often not visible to the eye). Of all the square shaped diamonds, the princess cut is the most sparkling and comes the closest to achieving the brilliance of a round brilliant cut diamond.

Emerald

An emerald is a form of step cuts with rows of parallel elongated facets, creating a unique look. The emerald cut is rectangular in shape with cropped corners and a large open table (upper most flat surface of the diamond) and highlights the diamond's clarity. The name comes from the fact that the shape was originally developed for the cutting of emeralds. Instead of the sparkle of a brilliant cut due to the fewer facets, an emerald cut produces a hall of mirrors effect with light and dark lines giving it an elegant appearance.

Asscher

A unique shaped diamond almost identical to an emerald cut, except it is a square. It is also known as a "square emerald". Like the emerald cut, an asscher cut highlights a diamond's clarity and has cropped corners. As it is a square, the cropped corners results in an almost octagonal shape and the step cut produces the appearance of concentric squares. Asscher cuts became popular in Art Deco jewellery. The modern asscher cut usually has larger stepped facets, a higher crown and smaller table, resulting in more brilliance than the emerald cut.

Marquise

The marquise is a brilliant style cut diamond with a distinct football shape. Its shape can maximise carat weight, creating the illusion that the diamond is much larger. Symmetry is very important in a marquise cut and the two end points should align. The elongated shape if set in a ring can make fingers appear longer and slender. 

Oval

The oval shaped diamond is a brilliant style cut similar to the round diamond, except it is eliptical. Similar to the marquise, the oval shape can accentuate long and slender fingers. 

Radiant

Cut corners are the key feature of this square or rectangular shaped diamond, which adds to its brilliance. Like the princess cut, the radiant cut has brilliant style cut facets creating a beautiful sparkling diamond.

Pear

This is another variation of the brilliant cut diamond, its shape created by a combination of the round and marquise cuts. It is also known as a "teardrop" shape. When set in a ring, it is worn with the tapered end pointing at the hand of the wearer. An elongated pear shaped diamond helps create the subtle illusion of longer and slimmer fingers. It is a popular choice for those who like the round brilliant style but want a more unique look of a fancy cut diamond.

Heart

The heart shape is the ultimate symbol of love. This is another modified brilliant style cut. Most heart shaped diamonds are round in appearance, producing a more brilliant diamond. For the perfect heart shaped diamond, it is important that the two halves are identical. This is a popular choice for a variety of jewellery, particularly for a ring or solitaire pendant.