Superficially, cut can be used to refer to the shape that the diamond has been cut into — round, emerald, oval, princess, pear, heart, radiant, etc. However, more essential to the meaning of “cut” in this context is how well the stone has actually been faceted, proportioned, and polished. These factors determine how the diamond interacts with the light, i.e., they are the key factors that impact brilliance. Diamond cuts are graded per the GIA system as Excellent, Very Good, Good, Fair, and Poor.