After reading our July blog article, you are more familiar with gem cutting types. Now, let’s have a look at the main gemstone cuts. The most usual method of fashioning a gem is to cut its surface into a number of flat faces, known as facets. This gives the stone its final shape and cut. Here is important to understand the difference between a gemstone’s “shape” and its “cut”. The shape refers only to the outward appearance of the gem (round-shaped, oval-shaped, or heart-shaped), while the cut refers to how it is faceted. In more detail, cut refers to the proportions, finish, symmetry, and polish of the stone. The gem cutter, or lapidary, tries to show the stone’s best features, taking into account its color, clarity, and weight.
The brilliant cut is the most popular for diamonds and for many other gemstones, particularly colorless ones. It ensures that maximum light is reflected out through the front of the stone, giving brightness and fire. The original round brilliant cut was developed by Marcel Tolkowsky in 1919. The modern round brilliant consists of 58 facets, or 57 if the culet is excluded.
The step cut, also known as trap cut, shows colored gemstones to advantage. It has a square or rectangular table facet and girdle, surrounded by a series of parallel four-sided facets. The corners of fragile gems may be removed, making octagonal stones, as, for example, in most emeralds. The resulting cut is called the emerald cut or modified step cut.
Mixed cuts optimize both the color and the fire of a gemstone by using different cuts on the crown (above the girdle) and pavilion (below the girdle) facets. Mixed-cut stones are usually rounded in outline. The most common mixed cut is a brilliant-cut crown with a step-cut pavilion. Sapphires, rubies, and most transparent colored stones are cut in this style.
Fancy cuts include variations on the round brilliant cut such as the oval, pear-shaped (pendeloque) and boat-shaped (navette or marquise) brilliants. This cut may be used for rare gemstones, or to make the most of a flawed or irregularly shaped gem.