The round brilliant cut diamond is by far the most popular and most researched diamond shape available today. For almost 100 years, diamond cutters have been using advanced theories of light behavior and precise mathematical calculations to optimize the fire and brilliance in a round diamond. In addition to being the most popular and researched shape, a round diamond will typically give you more flexibility in terms of balancing cut, color, and clarity grades while still getting the fire and brilliance you want.

Its beautiful brilliance and unique cut makes it a favorite for engagement rings. The princess has pointed corners and is traditionally square in shape. When choosing a color grade, consider that while the price of a J-color non-round diamond is exceptional, color may be slightly visible in its corners. Also, princess-cut diamonds can vary greatly in how square or rectangular they are. To find the dimension of princess you want, look for the length-to-width ratio in our interactive diamond search and on each diamond's detail page. This will determine what the diamond will look like when viewing it from above. Here are length-to-width ratios for princess-cut diamond shapes that are pleasing to the eye.

An even, perfectly symmetrical design popular among women with small hands or short fingers. Its elongated shape gives a flattering illusion of length to the hand.

An elongated shape with pointed ends inspired by the fetching smile of the Marquise de Pompadour and commissioned by the Sun King, France's Louis XIV, who wanted a diamond to match it. It is gorgeous when used as a solitaire or when enhanced by smaller diamonds.

A hybrid cut, combining the best of the oval and the marquise, it is shaped most like a sparkling teardrop. It also belongs to that category of diamond whose design most complements a hand with small or average-length fingers. It is particularly beautiful for pendants or earrings.

This ultimate symbol of romance is essentially a pear-shaped diamond with a cleft at the top. The skill of the cutter determines the beauty of the cut. Look for a stone with an even shape and a well-defined outline

This is a rectangular shape with cut corners. It is known as a step cut because its concentric broad, flat planes resemble stair steps. Since inclusions and inferior color are more pronounced in this particular cut, take pains to select a stone of superior clarity and color.

This is a spectacular wedge of brittle fire. First developed in Amsterdam, the exact design can vary depending on a particular diamond's natural characteristics and the cutter's personal preferences. It may be a traditional triangular shape with pointed corners or a more rounded triangular shape with 25 facets on the crown, 19 facets on the pavilion, and a polished girdle. It is definitely for the adventurous.