The Asscher cut is a unique shape with prismatic brilliance and a rectangular-faceted pavilion in the same style as the emerald cut.The standard number of main facets on an Asscher cut is usually 58 and the typical ratio for the more popular square-shaped Asscher cuts is 1.00 to 1.05.
The width of the cut corners may vary. With its deep pavilion, faceted culet, high crown and small table, the Asscher cut allows for tremendous lustre and creates a fascinating optical illusion known as the “Hall of Mirrors” effect.
The Asscher cut is referred to as a Square Emerald cut on a laboratory certificate, such as GIA or AGS. Although confusion reigns about what the differences are between an Asscher cut and a Square Emerald cut, they are in fact the same thing. However, there also exists a much rarer Royal Asscher cut, which is a patented version of the original Asscher cut with wide cut corners and 74 facets (instead of 58), and is classified as an octagonal step cut by the GIA.