The round brilliant is traditionally the most popular diamond on the market. It is the only perfectly symmetrical shape and offers unmatched brilliance. Rounds are the only shape GIA gives a cut grade. It is important to purchase only Excellent Cut rounds, as this is the only characteristic that impacts sparkle and brilliance. They hide color and clarity exceptionally well, allowing you to go up to two grades lower in color and clarity. Rounds are the most expensive shape per carat because the diamond cutter loses the most rough diamond in the process.

The unique look of the emerald cut diamond is created by the step cuts of its pavilion and large, open table. Instead of the sparkle of a brilliant-cut, emerald cut diamonds produce a hall-of-mirrors effect. Emerald cuts, like Asschers (below), mask color very well, but not inclusions (VS2 or better is recommended). They are the more popular of the two step cut shapes since their elongation makes them appear larger than Asschers.

Also called "teardrop," a pear-cut diamond gets its name because of its single point and rounded end. The unique shape is a way to make a bit more of a statement. Like ovals, pear-cut diamonds have a slimming effect on fingers, especially when they have an elongated length-to-width ratio. More than any other diamond shape, pear-cut diamonds appear the largest for their carat weight. While the length to width ratio of a classic pear shaped diamond is 1.40-1.70, a wider shape is preferred for a solitaire ring. Pears mask inclusions very well but tend to show warmth in their tips in lower colors.

Old Mine cut diamonds are antique cushion-cut diamonds with the same type of brilliance, color, and clarity-hiding properties as the Old European cut. Developed in 18th century Europe, old mine cushion cuts have a slightly curved edge that forms a soft square. They were made with a variety of facet patterns, but always with a small table, a high crown, and a larger culet. These diamonds were cut by hand and have a more natural, unprocessed look. If you compare one of these stones to a modern brilliant cut, you will notice the pattern reflected has more sculptural triangles than slivers of light.

The Old Mine cut was the earliest form of the brilliant cut, which means that the diamond was cut to allow the stone to sparkle under even the dimmest candlelight of the era.

The standards for a cushion cut vary more than most other shapes. While generally less brilliant than round brilliant diamonds, cushion-cut diamonds often have better fire, which is part of their appeal. The most prevalent modern cushion is the Cushion Modified Brilliant, which has an extra row of facets, giving it a crushed iced appearance. In contrast, a cushion brilliant has larger, fewer facets, and sparkles more similarly to a round brilliant. The typical requested shape is elongated, with a 1.10-1.25 length to width. Cushions hide inclusions very well and are known for their soft, pillow-like shape.