Princess cut diamonds are cut with brilliant radiating facets, just like a round diamond. A well cut one is exceptionally sparkly, but princess cuts (and other fancy diamodn shapes) don't have an industry standard cut grade like round diamonds do. Look for a depth percentage between 68%-75%, along with a table percentage in the same 68%-75% range for a nicely balanced and brilliant diamond. And like other shapes, look for excellent polish and symmetry for a well finished stone with even light distribution.