Blog Banner
Twitter koamaruFacebook koamaru


What is a Brilliant Cut Diamond?

By Stephanie Dore

What is brilliant if not the ultimate diamond industry buzzword? Well, when it comes to finding that all out sparkle that most of us are after, brilliant is basically everything. But not all diamonds are brilliant cut. Some are modified. Some are mixed. Some are step cuts. What’s a darling to do? Not to worry, we’ve got the low down on the brilliant cut diamond, what the name means, and all the alternatives you can dream.

Frank Darling cushion brilliant cut diamond bezel ring
Want a vintage look with modern brilliance? Explore the cushion brilliant cut diamond in a bezel setting.

Way Back When

Before we dig into the diamonds of today, let’s take a look back. Way back. To when diamonds were first faceted, say, the 14th century. At the time, though, they weren’t so sparkly. Folks were basically just polishing up the existing surfaces until the 15th century when people figured out that diamonds could be used to cut themselves (and are the only thing that can cut a diamond)! Thus began the quest to release the ultimate inner beauty of the diamond. There were table cuts, rose cuts, and eventually in the 18th century, old mine cuts. These were really the roots of the modern brilliant, though they were cut and finished by hand to sparkle in the candlelight rather than to the highly machined standards of today.

The Basics of a Brilliant Cut Diamond

Speaking of today, you could use the term “brilliant cut” to describe pretty much any old diamond that has been cut or polished with numerous facets to create, well, brilliance. Only, it’s never quite that simple. Because when most folks use the term, they’re actually referring to a relatively modern standard, one perfected back in 1919 by the one and only Marcel Tolkowsky. This very studied, very strict cutting of a round diamond consists of 58 facets (or 57 if there is no culet), with 33 on the crown (above the girdle) and 25 on the pavilion (below the girdle), that all radiate out from a center point to the girdle edge. And each one of these tiny facets must be placed just so to best create the sparkle we’re all in search of.

The most classic image of a brilliant cut is the classic round look.
Frank Darling four prong round brilliant cut solitaire engagement ring
There’s no cleaner of a look than the round brilliant solitaire.

Nothing Else Matters

And this, darlings, is why cut grade matters so much. Because cut is truly what determines the sparkle, and thus beauty, of a diamond. Today, each of those 58 facets is machined (lasers!) to perfection, cut with exceptional symmetry, finished with the highest of polish. Or at least, that’s what you want it to be. However, the lower you go in cut grade, the less perfected this stuff is — and the less sparkly your diamond. Since we’re here to help you avoid buying a big, dull rock, we can’t emphasize enough that everyone should prioritize cut grade when it comes to purchasing a modern round brilliant cut diamond. A well cut stone can look larger than its carat weight, hide inclusions from sight, and look brighter in color. What’s not to love about all that?

Modern Brilliant Cut Diamond Modifiers

This modern brilliant cut, while perfected in round diamonds, of course had to be applied to many shapes — princess, cushion, oval, pear… the list goes on. But every time it varies even slightly from its original faceting pattern or number of facets, then it becomes what we refer to as a “modified brilliant” cut. Which is exactly what it sounds like — a brilliant cut that has been, well, slightly (or severely) modified. What it should still have, however, is brilliance! Those facets should still radiate out, like spokes on a wheel, from the center point to the outer edges. They should still be symmetrical, and well polished, and designed at just the right angles to create lots of pretty sparkle.

Frank Darling oval brilliant cut diamond rings
The oval diamond is the most popular modified brilliant cut shape for its’ sparkle and finger coverage.
The hallmark of a well-cut diamond is great polish and symmetry, like this perfectly proportioned princess cut!

Make the Brilliant Cut Diamond Grade

The only hard part is that only round brilliant diamonds have official cut grades. Now, most retailers today — to make your life slightly less painful — do list a cut grade for what we call fancy shapes (anything other than round), which can help you narrow the field. Just make sure to really look at a diamond to ensure it’s sparkling bright. Every brilliant or modified brilliant cut should still have that, and once you look at a few, you’ll start to see the difference between a well cut and a poorly cut diamond. Trust us.

Step On It

Now, there’s one other major family of cut patterns we should mention — the step cuts. Step cut diamonds, like the emerald or Asscher cut, have elongated rectangular facets that go straight down each side rather than radiating out from the center. They really do look like little steps. There is still a center culet, and the facets will basically step from there to the outer edge, so all the same things are still important: the cut, symmetry, polish, et al. But what you won’t have is the same kind of sparkle pattern. Step cuts, instead, offer a subtle, sophisticated flash. We call it the hall of mirrors effect, because the elongated rectangular facets glint in the light. Step cuts are also not nearly as forgiving — their big, open facets reveal color and clarity concerns that a brilliant cut might hide. You’ll definitely have to look for a more balanced selection of the 4Cs if you go this route.

Can’t choose between brilliant cut and step? Combine the magic with a brilliant cut center and tapered baguette side stones.
Frank Darling radiant cut diamond bezel ring
The radiant cut diamond is perfect for sparkle seekers with a modern edge.

Mix and Match

There’s a chance you’ll also see something called a “mixed cut”, particularly if you’re shopping for a radiant cut diamond. What is this? Exactly what it sounds like! It’s a mix of some brilliant facets, with modifications, and some step cuts…a mish mash of sparkle if you may. In a radiant, you’ll find brilliant facets below the girdle and step cut facets on the top. It’s like the best of everything! 

You Can Have Whatever You Like

Whether you’re looking for an antique cut diamond, a modern round brilliant, or something a bit more modified, we’ve got your back. With more than 20,000 natural and lab created diamonds at your disposal, we’re betting you can find some sparkle that will satisfy. But if you don’t see what you want? Ping us at to let us know what you’re looking for, and how much you want to spend, and our Diamond Concierge will get you sorted.

Your cart is currently empty

View your wishlist or view all rings.