Diamond shapes

The process of transforming a rough (uncut) diamond into the finished polished stone is called manufacturing.

The final shape of a cut diamond is determined by a number of factors, including the shape of the original rough diamond, its color, number of inclusions and carat weight.

When considering the shape of a diamond it is also important to consider its cutting style.  The two concepts of shape and cutting style are often described by one term in the jewelry trade. For example the ’round brilliant’ refers to a diamond which is round in shape with a brilliant cutting style.

A brilliant cut has triangular, kite or lozenge-shaped facets that radiate outwards around the stone. The most popular cut for a diamond is the standard ’round brilliant’.

The standard round brilliant is round in outline with 57 facets – 33 facets on the crown and 24 facets on the pavilion. The base of the pavilion terminates in a point which is called a culet. This may be polished as a small facet bringing the total number of facets to 58.

Round brilliant cut diamonds are popular because this shape and cutting style shows more brilliance and sparkle than other shapes and cuts.

Although a large proportion of diamonds cut today are round brilliants, there are a number of other shapes that are cut in a similar way. The term ‘fancy shape’ is generally used to describe all shapes other than round. The most common alternative shapes to round, which are cut in the same way as round brilliants are:

This elliptical-shaped cut can have various arrangements of the back facets ranging from 4 to 8 pavilion main facets.

This drop-shaped variation of the brilliant cut can have various arrangements of the back facets ranging from four to eight pavilion main facets

The marquise cut, also known as the navette or boat shape, has various different arrangements of the back facets ranging from four to eight pavilion main facets

This cut has various arrangements of the back facets ranging from four to nine pavilion main facets

This is probably the second most popular style of diamond cut after the round brilliant and is also referred to as the Princess cut. As with the other fancy brilliant cuts, it can occur with a  different number of back facets.

This is another popular diamond shape which has evolved from older cuts.

A step cut has rows of facets which are usually four-sided and elongated and parallel to the girdle. Diamond shapes which are cut in this way include:

• Baguette
• Emerald
• Some square shapes (called radiants)

Step cuts do not produce as much fire and brilliance as brilliant cuts, but many people like their sleek and elegant look