The beautiful brilliance of diamonds is first brought to life when rough crystals of fine quality are given an appropriate cut. The final shape and facet arrangement are decided upon according to the shape of the rough and the current market demand. There are three styles of facet arrangement that are commonly used for diamonds: the brilliant cut, the step cut, and the princess cut. The photographs here clearly show that brilliant cuts and step cuts have a completely different brilliance, almost as if they were different gemstones.

Brilliant cuts display a strong brilliance from inside. All of the facet lines on this type of cut radiate outward toward the girdle (outer edge). Starting with the typical round brilliant cut, common brilliant-cut shapes include ovals, marquises, pears, and hearts. The five shapes shown in the photograph are all gem-quality diamonds, but it is obvious that the round exhibits the most brilliance. This is because shapes other than round have different lengths and widths, as in the marquise’s 2-to-1 length-to-width ratio, resulting in the presence of areas that do not totally reflect light.

The beauty of step cuts, the most well-known of which is the emerald cut, lies in their elegant brilliance and mesmerizing transparency. The name comes from the facets that are placed parallel to the girdle in a step-like fashion. Common shapes are emerald cuts, squares, rectangular baguettes, and small, trapezoidal tapered baguettes. Because defects are easier to see inside step cuts, they require especially high-quality rough material.