We all know that diamonds are most often polished and cut into round brilliant formats. The standard 57 to 58 facet design pioneered by Marcel Tolkowsky in 1919 took hold of the diamond industry and influenced how we want our diamonds to be cut today. This is common knowledge already, but what about the cutting preferences for the rest of the colored gemstone varieties?
Well today let's take a look at a handful of faceting styles and shapes that have captured the market's attention for best displaying the appeal and beauty of a gemstone. First off, probably the most utilized cut for rubies and sapphires (non-melee) would be the oval mixed-cut. The mixed faceting style simply refers to a gem that has both the brilliant-cut faceting style (triangular & kite shaped facets) and the step-cut faceting style (four sided facets). One might be on the crown, the other may be on the pavilion, or the reverse can also be true. This particular cutting style allows gem cutters to save weight from the original crystal, by cutting with a bit more bulge, especially if cutting the pavilion as a step-cut. Unlike diamond, the focus for colored gemstones is more about the intensity of color, and adding more material intensifies the selective absorption process that expresses a stone's color to our eyes. (Image credits to Sotheby's Auction House)
While rubies and sapphires are very often cut as mixed cuts, another very popular cutting orientation would be what the industry calls the 'Emerald Cut', which as you might have guessed, is very popularly used with emeralds. This is mainly because of how emerald crystals grow. Compared to the common tabular shapes of rough ruby, emerald crystals tend to grow as hexagonal prisms, or at least in elongated formats. The Emerald cut is a rectangular step-cut style that makes use of bevelled edges, and it's been the number one choice for emerald gemstones for a long time now. Even diamonds have adopted the appeal of this cut, because it accentuates their transparency and clarity, while presenting a very bold elegance and feel.
While the two styles above are probably the most popular choices for colored stone cuts today, another forerunner would be the cushion cut. Now the cushion cut is a little less defined than the previous two we mentioned. There are square cushions and rectangular cushions, as well as other shapes and varieties. The main difference between the cushion cut and other cuts, lies in the fact that cushion cuts have curving edges on all sides when seen face-up. It sort of resembles a pillow, or a cushion in shape outline- hence the name. This cutting preference allows a good amount of weight to be saved, and just like the standard oval mixed-cut, this appeals well for gem-cutters due to the fact that color can be better shown with more material.
Colored diamonds are also often cut into cushion shapes. The 'oval' or 'stadard' cushion cut pink diamond, pictured below, is a prime example of this. Color will always be one of the defining factors in gemstone valuation- whether it be the presence of it or the absence of it.
Each gemstone can be cut in a huge variety of choices. Emeralds can also be cut as mixed-cuts, and star rubies & sapphires can be polished into cabochon cuts. There are so many choices for gemstone appearances in today's trade, that the main factor to consider is your own personal preference. Brilliant faceting styles create sharper, more crisp brilliance patterns, while step-cut faceting styles can save more weight, and deepen color. Proportions and angles are also equally important so as not to create areas of windowing or extinction, where light can leak out of the stone rather than bounce back to the viewer's eye.
