Cutting the four equal edges of a perfect square from a natural, raw gemstone is easier than cutting a flawlessly round diamond. This is due to the fact that the form of a square-cut diamond resembles a pyramid. So, when the final pyramid is flipped on its head and inserted in the ring, the square component is visible. Is that a diamond is a polyiamond composed of two triangles, but a square is a polygon composed of four equal length sides and four 90-degree angles; and a regular quadrilateral composed of all 90-degree angles.