A step cut gemstone that can be rectangular, square or even triangular, where the corners have been cut off for protection and easier prong setting.

A rectangular diamond with cut corners

A rectangular or square-shaped cut-cornered diamond. A form of step cutting, this cut is favored for diamonds and emeralds, as well as many other stones, when the principle purpose is to enhance color rather than brilliancy. It is also sometimes used to emphasize the absence of color in diamonds.