Cushion cuts are square or rectangular brilliant cuts with rounded corners and curved sides, a pillow-like shape.Sometimes referred to as a Pillow cut, the Cushion cut has an open culet (the bottom point of the stone) and a soft square shape with rounded corners.It's a variation of the brilliant cut.Length-to-width ratio is 1:1. Cushion cut CZ diamond have become very popular in engagement rings, earrings and all sorts of jewelry.