Diamond shapes that are not round brilliant diamonds fall into the broad category of Fancy shapes. This is an enormous category with an ever-growing list of diamond shapes. In the world of diamonds there are currently 13 shapes that have been able to both withstand the test of time and remain popular shape choices. These are the Marquise, Oval, Pear, Heart, Asscher, Emerald, Princess, Cushion, Trillion, Radiant, Baguette, Old Miner, and European. Having a working familiarity with each of these shapes can be a wonderful aid in helping you to find the perfect diamond.

The Fancy shapes can be difficult to have the proper proportions, because the fancy shapes, by their very nature, do not have the kind of symmetry and set proportions that are found in round brilliants. The shapes found in Fancy shaped diamonds often have facets that are asymmetrical and elongated. These irregularities found in the facets result in not only a loss of brilliance, but can also cause shadows within the diamond. It is this shadowing that causes such effects as the "bowtie" effect to occur in some Fancy shapes. The "bowtie" effect is a dark shadow seen within the diamond that resembles a bowtie. This effect is typically found in Fancy shapes such as Oval, Marquise and Pear.

It can be easier to understand these 13 Fancy shapes by looking at them divided by their shape type. The four shape types are Modified Brilliant Cut, Step Cut, Mixed Cut and Old World Cut. As can be inferred from the names of these divisions, the basis for the four categories is the manner of the cut of the diamond. The type of cut is used as the division because the final shape is dependent on the type of cut the diamond cutter decides to utilize.