Round The round cut diamond is the most popular diamond shape, representing approximately 75% of all diamonds sold. Due to the mechanics of its shape, the round diamond is generally superior to fancy shapes at the proper reflection of light, maximizing potential brightness.
Oval Because the oval diamond is a modified brilliant-cut (like virtually all round cut diamonds), the two diamond shapes possess a similar fire and brilliance. However, oval cut diamonds have the added advantage of an elongated shape, which can create the illusion of greater size.
Marquise The marquise cut diamond is a football-shaped, modified brilliant-cut. Because the marquise diamond is long and narrow, it can also create the illusion of greater size. Carat for carat, the marquise diamond has one of the largest surface areas of any diamond shape, making it a good choice when trying to maximize perceived size.
Pear The modified brilliant-cut pear shaped diamond is a combination of a round and a marquise shape, with a tapered point on one end. Ideally, a pear shaped diamond should possess excellent or very good symmetry. The point should line up with the apex of the rounded end. The shoulders and wings (the upper and lower curves on the right and left side of the diamond) should form uniform, symmetrical curves.
Heart The modified brilliant-cut heart shaped diamond is a unique and unmistakable symbol of love, popular in solitaire pendants as well as rings. Heart shaped diamonds less than .50 carats may not be a good choice, since the heart shape is more difficult to perceive in smaller diamonds, especially after they are set in prongs.