The round brilliant cut diamond is 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.

To maximize the brilliance of a round diamond, select one in the two highest cut grades, ideal or very good, and choose ideal, excellent, or very good polish and symmetry grades. Read more about Round cut diamonds here.

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The princess is the most popular non-round diamond. Its beautiful brilliance in a sqareish shape makes it the most favorite non-round diamond engagement ring. The princess has pointed corners and is traditionally square in shape. Princess-cut diamonds can vary in how square or rectangular they are. To find the dimension of princess you want, look for the length-to-width ratio in our diamond search and on each diamond's detail page. This will determine what the diamond will look like when viewing it from the top Here are length-to-width ratios for princess-cut diamond shapes.

For a princess diamond shape that is square, look for length-to-width ratios between 1.00 and 1.05. If you prefer more of a rectangular shape, look for length-to-width ratios greater than 1.10. Read more about Princess cut diamonds here.

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The Emerald cut and Asscher cut are from the same cut group. What makes them different is that their facets create a unique optical appearance like a clear pool of water. Due to its larger, open table, this highlights the clarity of a diamond. If you choose an emerald-cut with a lower clarity grade, such as SI, be sure to review the clarity plot on the diamond certificate. Also, emerald-cut diamonds can vary greatly in how rectangular they are. If you'd prefer an emerald cut with a squared outline, look for an Asscher-cut diamond. To find the shape of emerald you want, look for the length-to-width ratio in our diamond search and on each diamond's detail page. The length-to-width ratio will determine the diamond's outline, or what it will look like when viewed from the top. The Emerald-cut diamond looks beautiful set with trapezoids, or tapered baguettes side stones. 

For the classic emerald-cut shape, look for a length-to-width ratio between 1.28 and 1.42 For the highest standard of cut available in an emerald-cut diamond. Read more about Emerald cut diamonds here.

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An oval diamond has beautiful brilliance that's similar to a round diamond. Oval diamonds are also very popular as their length accentuates long, slender fingers. This brilliant-cut diamond looks beautiful set with half-moon, Trillions, tapered baguettes, or pear-shaped side stones. To find the dimension of oval you want, look for the length-to-width ratio in our diamond search and on each diamond's detail page. The length-to-width ratio will determine the diamond's outline, or what it will look like when viewed from the top.

For the most traditional oval diamonds, look for length-to-width ratios between 1.3 and 1.68. Read more about Oval cut diamonds here.

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The marquise diamond maximizes your carat weight, giving you a much larger-looking diamond. This brilliant-cut diamond looks beautiful set with round, Trillions, tapered baguettes,  or pear-shaped side stones, and the length of the marquise makes fingers appear long and slender. To find the dimension of marquise you want, look for the length-to-width ratio in our diamond search and on each diamond's detail page. The length-to-width ratio will determine the diamond's outline, or what it will look like when viewed from the top.

For the most traditional marquise-cut diamonds, look for length-to-width ratios between 1.75 and 2.25. Read more about Marquise cut diamonds here.

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This brilliant-cut diamond is also known as teardrop makes it a popular choice for a variety of diamond jewelry especially in pendants and earrings.  If you choose an elongated pear shape, like the oval and the marquise the length of the diamond will create a subtle slimming effect on the fingers. This brilliant-cut diamond looks beautiful set with round, Trillions, tapered baguettes, or pear-shaped side stones.

To understand what the diamond will look like when viewing it from above, look for the length-to-width ratio on each diamond's detail page. For the most traditional pear-shaped diamond, look for a length-to-width ratio between 1.45 and 1.75. Read more about Pear Shaped diamonds here.

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Trimmed corners are the signature of the radiant., and they help make the radiant-cut a popular. A radiant-cut looks beautiful set with baguette or trapezoids side-diamonds. Radiant-cut diamonds are available in shapes ranging from square to rectangular. To find the dimension of radiant you want, look for the length-to-width ratio in our diamond search and on each diamond's detail page. The length-to-width ratio will determine the diamond's outline, or what it will look like when viewed from the top.

For a radiant diamond shape that is square, look for length-to-width ratios between 1 and 1.05. If you prefer more of a rectangular shape, look for length-to-width ratios greater than 1.10. Read more about Radiant cut diamonds here.

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The Cushion-cut diamond also known as "pillow-cut" diamonds, has been popular for more than a century. The cushions have rounded corners and larger facets to increase their brilliance. Cushion-cut diamonds are available in shapes ranging from square to rectangular. To find the dimension of cushion you want, look for the length-to-width ratio in our interactive diamond search and on each diamond's detail page. The length-to-width ratio will determine the diamond's outline, or what it will look like when viewed from the top. The cushion looks beautiful set with round, Trillions, tapered baguettes, or pear-shaped side stones.

For a cushion-cut diamond that is square, look for length-to-width ratios between 1 and 1.05. If you prefer more of a rectangular shape, look for length-to-width ratios greater than 1.15. Read more about Cushion cut diamonds here.

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The heart is the ultimate symbol of love. The unique look of the heart-shaped diamond helps make it a distinctive choice for a variety of diamond jewelry. To find the dimension of heart-shape you want, look for the length-to-width ratio in our interactive diamond search and on each diamond's detail page. The length-to-width ratio will determine the diamond's outline, or what it will look like when viewed from the top. The heart looks beautiful set with round, Trillions, tapered baguettes, or pear-shaped side stones.

For a more traditional heart-shaped diamond, look for length-to-width ratios between .90 and 1.15. Read more about Heart shaped diamonds here.

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