All About Rounds

The round brilliant is the most popular diamond shape in the world, and for good reason. Its 58-facet design maximizes light return in a way no other shape can quite match. Whether you're drawn to the classic solitaire or a more elaborate setting, a round diamond wears beautifully in almost anything.

This guide covers what to look for and how we approach selecting them.

Why Choose a Round Lab Diamond?

The round brilliant cut was perfected in 1919 by Marcel Tolkowsky, who used geometry and optics to maximize light return. The result is a 58-facet (57 if the culet is excluded) cut that reflects more light than any other shape. It's why rounds have remained the most popular diamond shape for over a century.

Rounds with ideal-cut proportions, perfectly balanced between the table and pavilion, can display what's known as "hearts and arrows": a precise optical pattern visible under magnification.

The popularity of round diamonds belies the complexity of this classic cut. Even with modern technology, cutting a round shape from a rough diamond crystal nearly always results in a loss of weight around 50%-meaning the rough crystal from which a round brilliant is cut must be larger than other shapes.

How we Curate Round Brilliants

Brilliant cuts with perfect symmetry between their table (top) and pavilion (bottom) are known as "ideal cuts". While often misused as a marketing term applied to other shapes, ideal cuts only apply to round brilliant diamonds.

For rounds, we look for clean, consistent light return with no milkiness, graining, or dull patches. The hearts and arrows pattern is one of the clearest signs of a well-cut diamond.

Even with identical grades, two diamonds can appear very different in person. Light performance, crystal quality, and growth conditions are ultimately what determine how your diamond looks and these qualities must be evaluated in person.

Our Favorite Settings for Round Diamonds

One of the best things about choosing a round diamond is that they’re endlessly versatile and look good in just about any setting style.

Six-prong and other classic solitaire settings remain popular among our clients, and bezel styles are becoming an increasingly requested option. From halos to three stones, you really can’t go wrong with this shape!

We offer a wide range of setting styles to suit any shape. Shop online or work with a Diamond Concierge to design a custom style that's all your own.