Diamond shape differs from the others from diamond cut, the two will often be combined. When a jeweler discusses a brilliant cut diamond, she's speaking about the angle at which the diamond is shaped, not perhaps the diamond is in a round, or square, or oval shape. You'll be familiar with "this is often a round brilliant cut" which lets you know both shape and also the cut with the diamond. While shape isn't technically one with the 4 c's, it is only as important if you would like your future wife to be very pleased with her new ring. []