Diamonds come in many different cuts and shapes: round, princess, oval, cushion, emerald, heart, marquise, pear, and radiant, baguette, rose, brilliant, and French cut. To a jeweler, cut and shape are not exactly the same thing, since shape refers to the cut of the outer shape of the diamond, and cut refers to not only the outer shape but also the style of the actual cuts of the individual facets. For someone choosing a diamond, the outer shape of the diamond is usually one of the primary considerations.
Personal preference is the main factor in choosing. However, some stones are also easier to find settings for than others – for example, round stones fit more easily into more popular settings. Both the outer shape and the way the facets are cut can affect the reflectiveness and the appearance of color in the diamond. The quality of the cut is another factor in choosing a diamond and in determining its value. The Gemological Institute of America grades diamonds as poor, good or excellent, taking into consideration the diamond’s fire, brightness, and scintillation, which means the way it interacts with light and sparkles. But the most important thing is that you love the way it shines.