The second step in buying a diamond would be deciding on the shape of the diamond you wish to purchase. The main diamond shapes being round, princess, asscher, cushion, marquise, oval, radiant, pear, heart and emerald shaped. The classic, timeless and most popular shape is a round it is also the most expensive as you lose the most amount when cutting a round from a rough diamond into a faceted diamond. There is no wrong shape of diamond. Most of all it is personal preference enjoy choosing!