Nothing is more classic and timeless than a round cut diamond. Whether it’s a solitaire or surrounded by diamond accents, this elegant gem always makes a statement.
There’s a reason this diamond shape consistently tops the diamond sales charts, why we return to it again and again. It’s unendingly versatile, and — the round brilliant diamond cut in particular — shows the very best display of brightness, fire, and scintillation that a diamond can possibly offer.
Let’s take a closer look at this stunning, elegant design.
What is a Round Cut Diamond?
Although we talk about “round cuts”, round actually refers to the shape, or outline, of the diamond. There are a number of different diamond cuts with a round shape, and we’ll talk about those below.
Despite its apparently unassuming and innocent shape, round diamonds have been examined and perfected more than any other diamond shape. Over the years, diamond cutters and gemologists have put the round diamond through numerous incarnations, trying to find the very best design possible to maximize all the diamond has to offer. What they eventually came up with was a perfect architectural marvel, taking any light directed at it and leading it in a stunning dance of glittering, multicolored sparkle (we have Marcel Tolkowsky’s work in 1919 to thank for that).
While many of these concepts can be applied to cut diamonds of any shape, a round diamond is the absolute best vehicle for this kind of light return. This is one of the reasons why round diamonds account for 75% of all diamonds sold (!), and 60% of all engagement rings.
In addition to their brilliance, round diamonds owe their popularity to their timeless simplicity and the fact that they go with any style. Round diamonds work well in trendy, modern settings as well as antique and vintage-inspired designs, as trim solitaires and in eye-catching halos. In short, one hundred very different women could each take a round cut diamond and wear it in one hundred completely contrasting ways — they’re that versatile.
Varieties of Round Cut Diamonds
The rose is actually a cutting style that can be applied to just about any shape, but it’s most commonly seen in round diamonds. It was developed back in the 15th century when diamond cutters were just beginning to understand the glittering potential of this marvelous stone, and the rose cut they created is still in use in jewelry designs today.
Rose cut diamonds can have anywhere from three to twenty-four facets. Contrary to most modern diamond cuts, the rose cut has no pavilion. It’s completely flat on the bottom, like a cabochon. This keeps it low and intimately close to the finger.
The shape is inspired by the unfurling petals of a rose and although it doesn’t have the same glittering sparkle of more modern round diamonds, the rose cut diamond maintains a loyal cult following for its soft, luminescent glow.
After the rose cut, diamond cutters continued improving their designs and came up with what we now call the “old mine cut”. This has been in use since around the end of the 17th century.
This diamond cut does feature a pavilion, coming closer to the classic diamond shape we recognize today. The shape of the old mine diamond is slightly squared off, similar to a cushion cut, because early gem cutters were trying to follow the natural octahedral shape of the rough stone. It also has a smaller table (that’s the large facet right in the middle, facing up), and a large, prominent culet (that’s the tiny facet at the very bottom, opposite the table).
Next came what we call the “old European cut”. This was created in the late 19th century as cutting technology evolved and allowed diamond cutters to create smoother, more precise facets.
Like the old mine and the round brilliant cuts, the old European has 58 facets. The table was a little bigger than the old mine and the culet a little smaller, and the edges became more round and symmetrical. The facets are leaner and sharper in this cut and we can see some of the diamond’s trademark rainbow dispersion showing through, though old European cut diamonds are still being carved by hand instead of machines.
By the turn of the 20th century, we arrive at the magnum opus of the fine jewelry industry: the round brilliant cut. By this point, gemologists have learned to take a mathematical approach to the depths and angles of the diamond’s 58 facets and measure how each of these affects the light that enters into the stone.
In a round brilliant, light comes in through the face of the diamond, hits one of the carefully arranged facets in the pavilion, and begins ricocheting through the geometric maze of the stone. Some of this light reflects back at us and some of it breaks off into sections of spectral color, giving us glimpses of stunning rainbow hues.
In addition to being a soft, timeless shape to fit any style, the round brilliant is the perfect shape to bring out all the unique optical qualities that this magical gem has to offer.
Today, most of the diamonds we see being sold in jewelry boutiques are round cuts, and of those, nearly all of them are round brilliants. This fashionable, adaptable design represents generations of study and craftsmanship, and will never go out of style.
What to Look For When Buying a Round Cut Diamond
It’s impossible to talk about the classic round brilliant diamond without mentioning the 4Cs of diamond grading: cut, color, clarity, and carat weight. It’s essential to be familiar with these quality factors to make sure that you’re getting the best value for your money, and going home with a diamond that will show you all the sparkle and beauty that it has to offer.
Let’s start with the big ticket and work backward. Carat is the first thing many people think about when they begin shopping for diamond jewelry. It’s the first assessment standard we hear used to describe diamonds in the tabloids, in retail shops, and in buyers’ guides.
Carat is actually not a measurement of size – it’s a measurement of weight. One carat is equal to 0.2 grams, or a fifth of a gram. Most 1ct round diamonds are around 6mm in diameter, depending on how wide and deep the particular stone is cut. Some stones with higher densities, like sapphires, will be a little smaller than diamonds of the same carat weight.
Certain solid numbers, called “magic sizes”, sell for a higher per-carat price than diamonds that fall below those numbers. These are things like 1ct, 1.50ct, etc. When fashioning a diamond out of rough stone, a cutter often has to prioritize whether to give a diamond the best cut proportions, to cut in a way that skims off small inclusions and raises the clarity grade, or to retain a little more of the rough stone and raises the final carat weight. The best diamond cutters will be able to balance all of these things to get the most beautiful stone possible but, as you can see, carat alone is not an indication of quality.
In fact, if you are working with a tight budget, it’s nearly always recommended that carat weight should become the last priority after the other three grading factors so that you can get the most beautiful stone possible. While style and personal preference play a part, a good size for a round diamond solitaire is usually between 0.50ct and 1.50ct.
After carat we have clarity, which refers to how clean and uninterrupted the interior of the diamond looks. Diamonds can have inclusions, which are characteristics inside the stone, and blemishes, which are things like nicks and scratches confined to the surface of the stone.
While these imperfections (collectively called “clarity characteristics”) are usually thought of as a negative thing, they are a very natural part of your gem that shows that it’s a real diamond and, more importantly, shows that it’s your diamond. Each stone is unique, and the clarity characteristics help identify your stone if it is ever separated from you.
Diamond clarity is graded on a scale from F (flawless) to IF (internally flawless), VVS1-2 (very, very slightly included), VS1-2 (very slightly included), SI12 (slightly included), and I1-3 (included). These are the clarity grades of diamonds used in jewelry. After I3 we get into industrial grades, diamonds that are considered unfit for jewelry and are instead used in things like cutting tools due to their exceptional hardness.
It’s only once we reach about SI2 that we have inclusions visible to our naked eyes – above this grade, the clarity characteristics are so small that they can only be seen with a microscope. For this reason, the very best value for your round cut diamond is between VS1 and SI1. They will look clean and unblemished when viewed face up for a much lower price than a stone in the higher clarity grades.
Round brilliant diamonds, in particular, have such a sparkling and complex facet arrangement that often minute visible inclusions are hidden from view. Compared to something like an emerald cut, which shows any sort of deviation very readily, round brilliants are designed to minimize flaws. This means that the budget-conscious shopper can lean a little lower on the clarity grade while still getting a beautiful, clean, sparkling diamond.
The next of the 4Cs is color. This refers to the universal D-Z color scale put down by the Gemological Institute of America back in the 1940s. It is the range of standard colorless diamonds (not to be confused with fancy color diamonds), on a scale from entirely colorless (D-F) through to near colorless (G-J), faint (K-M), very light (N-R), and light (S-Z).
Colorless diamonds will command the highest prices. Gems lower on the color scale, with hints of yellow, brown, or gray, will always sell for a lower price per carat.
The quality and style of the diamond cut will affect how we perceive any “off” colors in the stone. Much like we saw in clarity, round brilliants are designed to show the most brilliance possible and minimize any detracting flaws. A round brilliant diamond will almost always look whiter and brighter than other diamond cuts of the same grade on the color scale. Likewise, off colors will be more apparent in a rose or old mine cut round diamond. This is something to keep in mind when shopping for your round cut diamond and deciding where to prioritize your budget.
Lastly, we have the single most important quality consideration when shopping for a diamond: cut. This refers to more than just the shape of the diamond, or even the style (for example, brilliant or rose cut). It refers to how expertly the diamond cutter adhered to the ideal proportions for the particular shape chosen for that diamond, how even and well-balanced the facets are, and how the angles interact with each other to offer the best display of light possible.
Diamond cut is a complex mathematical science as well as an art, and a poorly cut diamond will lose much of what makes a diamond so precious and beautiful.
You can read more about the ideal proportions for your round cut diamond and how they interact with the other diamond grading factors in our guide to understanding diamond cuts. Safe to say, when shopping for a round diamond it’s highly recommended that you limit your short list to stones with cut grades of Ideal, Excellent, or Very Good.
Which Settings Pair Best with Round Cut Diamonds?
The wonderful thing about round diamonds is that they go with absolutely everything. They’re great for jewelry makers, because there is no limit to what their imagination can come up with, and they’re great for shoppers because a round cut diamond can complement any style or personality. Whether your signature look is more Breakfast at Tiffany’s or more Bring it On, you can be assured that there’s a perfect round cut diamond out there for you.
The classic, reliable choice for a round cut diamond is a solitaire — gently elevated with four or six prongs to hold it steady and show off its brightness and scintillation. This star player needs no supporting cast to display its beauty. Very active women might want to consider a bezel setting in place of the prongs, which gives even more protection to the edges.
Another timeless choice for a round-cut diamond is the halo setting, where the center diamond is surrounded by a ring of smaller diamonds. The fantastic thing about this setting is it makes your diamond look a lot bigger, up to double its carat weight, for a very affordable price. Usually, the halo is made up of round cut diamonds as well, though you can find them in diamonds of any shape.
For a little extra sparkle you can go for a trinity, or three-stone design. This might be a row of three round cut diamonds, or it might be a round cut diamond flanked by trillion or baguette accents. Think of the side diamonds like stage lights drawing attention to the beautiful round cut diamond in the center.
For the graceful, vintage-inspired dame, you can look at the wide array of vintage jewelry settings on the market. There are genuine vintage and antique rings available with round brilliant cut diamonds and the older rose, old mine, and old European diamonds. There are also stunning reproductions and new styles inspired by old motifs. Websites like Etsy are great for this, where independent jewelers create innovative, breathtaking designs on a smaller scale.
The adaptability of the round-cut diamond means it’s as at home with an art deco debutante as it is in a highrise office break room.
How Much Do Round Cut Diamonds Cost?
The value of round diamonds varies quite a bit based on the quality factors of cut, clarity, color, and carat weight. Tiny round cuts that are used either as accents or in modern minimalist designs can be bought for only a few hundred dollars. Substantial diamonds of 1ct start at around $2500 and can reach prices of up to $20,000, depending on quality. Very special diamonds, such as fancy colors, can go for even more.
Generally, the best value for a round cut diamond of one carat is between $3000 and $5000. Round cut diamonds, particularly round brilliants, are among the most expensive diamond shapes (matched only by very difficult or unique shapes, such as hearts or stars). This is partly due to their vast popularity, but also because a high proportion of rough stone is lost during the cutting process. Compared to other diamond shapes, the carat weight retained in the final piece is quite low.
Round Cut Diamond FAQ
The round cut diamond is as timeless as it gets. Unlike other shapes which come with their own cultural associations, the round cut is a blank canvas for you to paint your story on. The round cut diamond represents a tiny, glittering world of possibility. This is also a wonderful metaphor for a new marriage, if you decide to opt for a round cut diamond engagement ring!
Although round cut diamonds are the most expensive for their carat weight, they are also one style that never falls out of fashion. In general, round cuts retain their value better than specialty cuts because there is always a high demand for them.
If you’re working with a limited budget and want a large stone, it may be worth considering some of the other fancy shapes available. However, when buying a round cut diamond you can rest assured that it will never fall out of style and it will always suit your own style, even as you change and grow.
In addition to being the hardest natural gemstone, round cuts are particularly great for everyday wear because they don’t have any delicate points or corners. They’re not indestructible, however, so they’re best worn in protective prong or bezel settings and gently cleaned with a baby toothbrush or soft cloth.
Beautiful, Brilliant, and Always in Style
Whether you’re looking for an elegant, vintage-inspired showstopper or a modern, trendy statement piece, a round cut diamond is a safe and classic choice for women from any walk of life.
Growing from humble origins as a rosebud-inspired gem to the perfect architectural marvel of the round brilliant cut, the round cut shows us the diamond as the very best it can possibly be. After all, why should you settle for anything less?