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One-Carat Oval Diamonds: the Complete Guide

The one-carat round diamond is the most popular engagement ring stone. However, there are many other diamond shapes available for couples who want to try something different. The oval cut is an elegant and versatile option that actually looks bigger than a round cut. Our guide will help you compare one-carat oval diamonds to one-carat rounds, so you can decide if an oval is right for you.
By Laurie Mega , International Gem Society 17 minutes read
oval-cut diamond white gold ring - F IF

1.01-ct oval-cut diamond, F color, IF clarity, in a scalloped diamond halo and pavé 18K white gold shank. © CustomMade. Used with permission.

What is an Oval Cut?

Oval diamonds have an oval shape, of course, when viewed from the top. They can come in elongated or shortened shapes. Typically, the most desirable ovals have symmetrical, rounded outlines, without pointed ends or straight sides.

Ovals are considered fancy cuts or “fancies.” Unlike rounds, which have a very detailed, well-established cut grading system and receive cut grades from gemology laboratories, fancy cuts are evaluated differently. The process is much more subjective, ultimately coming down to the overall appeal of the stone to the customer instead of how close some measurements come to a standard.

Like rounds, most modern oval diamonds are cut in a brilliant style. These stones have triangular and kite-shaped facets designed to maximize brilliance and scintillation. That means ovals can be very bright and sparkly.

brilliant oval cut - parts

Oval brilliant cut diagram, top view (left) and bottom view (right). Ovals are divided into seven parts or zones: two heads or ends, four shoulders, and a belly.

How Much Do One-Carat Oval Diamonds Cost?

A weight of one carat is a popular choice for a diamond engagement ring stone, regardless of the cut. If you’re on a tight budget, ovals deserve special consideration. Choosing a one-carat oval rather than a one-carat round will not only save you money but also get you a visually larger stone.

Ovals cost less than rounds of the same carat weight. For example, on Blue Nile, the average price of a one-carat round is $2,275. The average cost of a one-carat oval is $1,709.

Why are Ovals Less Expensive Than Rounds?

Ovals cost less than rounds for two basic reasons:

  • Rounds are more popular, so they’re in greater demand. There’s just less demand for ovals.
  • Diamond cutters have to cut shapes out of rough natural diamond crystals. The material that’s cut away from the shape is wasted. Cutting ovals uses up less rough material than cutting rounds,  so diamond cutters can “convert” more of their rough into sellable stones if they cut ovals.

If you shop for lab-created oval diamonds, you’ll save even more money. Since synthetic crystals can be “made-to-order” in more regular shapes than natural crystals, there’s even less rough material wasted. (The synthetic rough is also “cleaner,” with none of the flaws that have to be cut out of natural rough).

lab-created oval-cut diamond

14k white gold ring with a 0.90-ct, lab-created, oval-cut diamond, E color, VVS2 clarity. © CustomMade. Used with permission.

Do Ovals Actually Look Bigger Than Rounds?

If you compare an oval and a round diamond of the same carat weight, you’ll see that the oval looks bigger. That’s because an oval diamond has a larger, “face-up” surface area than a round. An oval diamond ring will also make the hand and finger look slimmer and longer, if the stone is set lengthwise.

Lower prices combined with these optical effects make one-carat oval diamonds attractive options for budget-conscious couples. You can get a diamond that looks bigger for less money, if you choose an oval instead of a round.

Compare these 1-ct diamonds, both in petite solitaire settings. Although the round and oval weigh the same, the oval diamond looks bigger. © Blue Nile. Used with permission.

What is the Bowtie Effect?

You might have been warned about the oval cut’s bowtie effect, a dark shape in the middle of the diamond that resembles a formal bowtie. Light enters this area but isn’t reflected back to the viewer.

Diamond cutters usually try to cut brilliant ovals so they reflect as much light as possible. (Ovals can be one of the sparkliest diamond cuts). Nevertheless, all ovals show this effect to some degree. The size and visibility of bowties vary from stone to stone.

You won’t find bowties in round diamonds. If cut poorly, rounds won’t sparkle and shine as much as they should, but you won’t see dark areas in the middle of the stones.

The bowtie in the first oval, a 1-ct, H color, VS1 clarity stone, is very obvious. The bowtie in the second oval, a 1.02-ct, H color, VS2 clarity stone, is hardly noticeable. (Note that the oval with the lower clarity has a far less noticeable bowtie. Bowties are purely related to the cut. They aren’t clarity defects).

Should I Avoid Ovals Because of the Bowtie?

Some consumers won’t even think of buying an oval-cut diamond because of the bowtie effect. If that includes you, that’s your choice and that’s OK. On the other hand, some consumers like the dark pattern.

If you’re willing to consider a oval, bowtie and all, it just comes down to how noticeable a bowtie you’ll accept. The bowtie is a purely visual effect. It doesn’t indicate a structural flaw in the diamond. A smaller, less visible bowtie just means the diamond cutter wanted to minimize the bowtie.

If you’re shopping for one-carat oval diamonds, examine the stones you’re considering from several angles, either in person or via videos if you’re buying online. Get a good sense of how the bowtie looks before you make any decision.

Even if you’re OK with the bowtie, try to choose an oval that’s still sparkly and has good brilliance in other areas.

How to Shop for One-Carat Oval Diamonds

If you’ve made it this far, you either like the idea of saving some money on your engagement ring, love the bowtie, or both. So, what do you need to look for to find a good oval-cut diamond?

Watch How Your Diamond Performs

Move your diamond in the light (or use the magnified videos of diamonds on sites like James Allen and Blue Nile) and watch for three things:

  • Brilliance: how the diamond reflects white light, “brightness.”
  • Scintillation: how the diamond sparkles, the contrast between light and dark points.
  • Dispersion: how the diamond breaks up light into many colors within the stone, its “fire.”

Look for a diamond that shows the brightness, sparkle, and fire that you want. Round brilliants are specifically cut to maximize these qualities and will usually exceed ovals in performance. Nevertheless, a well-cut oval should still display these qualities, even though it has a bowtie.

Both the 1-ct round and the 1-ct oval diamond have D color, SI1 clarity, and the best cuts you can get for each type. (The oval’s bowtie is also not conspicuous). The round costs $4,484, while the oval costs $3,725.

Ask Your Jeweler About Total Depth Percentage and Table Width

If you’re shopping in person, ask your jeweler or staff gemologist for the oval’s total depth percentage and table width. (If you’re shopping online, read the diamond description or contact one of the site’s online experts). These measurements can give you some indication of how well the diamond will perform. Try to limit your searches to ovals with depths between 58 and 63% and table widths between 53 and 63%. Blue Nile lets you enter ranges for total depth and table width when you search their inventory online.

Table width is expressed as a percentage. The length of the table at its widest point is divided by the length of the stone. Here you can see two one-carat oval diamonds, one with a 54% table width, the other with a 63% table width. © Blue Nile. Used with permission.

Pay special attention to your oval’s table. This horizontal plane at the very top of the diamond is the biggest facet on the stone, and most of the light that enters the diamond reflects back through it. Ovals have bigger tables than rounds, which helps them look larger than rounds, but this can also impact their performance. Ovals with tables that are too large will look dull.

oval diamond with large table

This 1.01-ct, H color, SI1 clarity oval has a very large, lifeless table. © James Allen. Used with permission.

What Oval Shape do You Prefer?

Don’t all oval-cut diamonds have oval shapes? Yes, that’s true. However, there are different kinds of ovals, and no two oval diamonds are alike.

Look for an oval shape with good proportions and symmetry, so that it will look balanced and attractive on your finger. Avoid ovals that look more egg-shaped or have pointed or squared heads. These will look awkward, especially if they’re set against other smaller stones. You should also avoid ovals with bellies too wide when compared to the heads.

asymmetrical oval

If you look carefully, you can see that the upper left shoulder of this oval-cut diamond has an asymmetrical bulge. © James Allen. Used with permission.

Ask Your Jeweler About Length-to-Width Ratios

A stone’s length-to-width ratio is a useful bit of information for jewelers as well as consumers. The length of the oval divided by its width (L/W) will indicate of how thick or thin your stone appears. Both brick-and-mortar jewelers and online vendors should provide this information. Blue Nile lets you specify L/W values when you search their inventory online.

Most consumers prefer an oval’s L/W to fall somewhere between 1.3 and 1.5. (Stones with lower L/Ws are thicker; those with higher L/Ws are thinner). Restricting your search to ovals within these values will save you some time. However, ultimately, choose the stone with the dimensions most pleasing to your eye.

All these oval diamonds weigh one carat. Which L/W do you find most appealing? © Blue Nile. Used with permission.

What’s the Best Clarity for One-Carat Oval Diamonds?

Make sure to review the lab report of any diamond you’re thinking of buying. Among other valuable pieces of information, you’ll find the diamond’s clarity grade.

A diamond’s clarity grade doesn’t just refer to its transparency. It also specifies the type, size, and number of imperfections on its surface as well as inside, such as tiny bits of minerals and even air bubbles that formed within the diamond itself. These are called inclusions. Larger, darker, and/or more numerous flaws will result in a lower clarity grade.

Clarity grades for diamonds in the GIA system, the most widely used system, range from “Flawless” (F) to “Included” (I), with several grades in between. Some grades even have numbered subdivisions. Higher numbers mean a higher grade.

A diamond doesn’t have to be graded Flawless to be beautiful. After all, gemologists grade these diamonds under 10X magnification. Instead of looking for a oval-cut diamond with a high clarity grade, look for one that’s eye-clean. That means it has no flaws visible to the naked eye. For one-carat oval diamonds, you can even go as flow as “Very Slightly Included 2” (VS2, a mid-range grade) or “Slightly Included 1” (SI1, a low-end grade) and still find eye-clean stones.

SI1 clarity oval diamond

This 1-ct, SI1 clarity, G color oval-cut diamond has some dark inclusions near the left head and a light-colored, small flaw under the table. (You can see it better if you watch the stone rotate in the video). Once this stone is mounted, these inclusions probably won’t be visible at a normal viewing distance, about 6 inches from your eyes. © James Allen. Used with permission.

Clarity Caveats

For any diamond, the location of inclusions can be even more significant than the clarity grade itself. This is especially true for ovals. Although brilliant cuts, like rounds and ovals, are good at hiding flaws with their brightness and scintillation, ovals do have a disadvantage. Since they have large tables, which tend to show less brilliance, flaws in this area may be very noticeable.

Avoid ovals with noticeable or numerous inclusions under the table facet. On the other hand, inclusions near the edges may be harder to see with the naked eye. The oval’s brilliance or an expertly placed prong may also be able to hide them. You can save a lot of money if you don’t limit yourself to high clarity grades and, instead, take the time to search for an eye-clean stone.

If you’re shopping at a brick-and-mortar store, make sure the jeweler shows you the diamond under magnification as well as from different angles and distances. If you’re shopping online, use viewing tools and magnified videos to examine the stone.

VS2-SI1 clarity oval diamond

Compare this 1-ct, VS2-SI1 clarity oval diamond with the previous SI1 clarity stone. Even in its 14k white gold setting, you can still see small but numerous dark inclusions under its table. Photo courtesy of liveauctioneers.com and Designer Vintage Estate Auctioneers.

What’s the Best Color for One-Carat Oval Diamonds?

You can compromise on diamond color and find considerable savings. That’s assuming you’re staying with white or colorless diamonds, the kind most commonly used for engagement rings.

Color Grades

All colorless diamonds receive a color grade. Stones that come closest to colorless get a D, the highest grade. Stones with slight yellow or brown tints get letter grades that go further down the alphabet as they show more color, all the way to Z.

Fancy colored diamonds, like pinks or blues, have a different grading system and cost far more than their colorless counterparts.

Although rounds are usually more expensive than ovals of the same carat size, that goes out the window when you compare the prices of colorless with those of fancy colored diamonds. This 1.00-ct round with D color, IF clarity, and an Excellent cut costs $13,600. However, this 1.00-ct oval diamond has fancy, light purplish pink color and an I1 clarity. It also has a saturation of “Fancy Light,” one of the lowest grades. Nevertheless, it costs $51,070.

Do Ovals Show More Color Than Rounds?

Oval diamonds show more color than round diamonds, especially at the heads and edges. The larger the stone, the more color they show, too. However, at one-carat size, if you stay at an H color or higher, you can still get a stone that will appear white. You might be able to find an I or J color stone that will look white, but this will require some diligent searching.

Both these 1-carat diamonds have J color and SI1 clarity. However, the round cut still looks white. The oval cut clearly shows hints of color at the heads.

Color Grades and Price Differences for One-Carat Oval Diamonds

These one-carat oval diamonds all have VS2 clarity but different color grades, from J up to F. Even though slight differences between adjacent color grades can be difficult to distinguish, the prices of these stones vary significantly by color. © James Allen. Used with permission.

How to Make a Diamond Look Whiter

There are some tricks to making a diamond look whiter. Once you’ve narrowed your search to a few stones, check them against the metal color you’ve chosen for your ring — white, yellow, or rose.

White Gold

Diamonds with high color grades, from colorless (D through F) to near colorless (G through J), pair best with platinum or white gold. However, since ovals tend to show more color than rounds, check any I or J color ovals carefully against a white gold band.

H color oval diamond in white gold setting

In a 14k white gold setting, this H color diamond looks very white. © CustomMade. Used with permission.

Yellow Gold

Setting diamonds with high color grades in yellow gold may make the stones appear off-color, despite their grades. Ovals with G through J colors might look white in yellow gold, but you’ll need to check these carefully. However, if your heart is set on a yellow gold ring, ask your jeweler to use platinum or white gold prongs for high color grade stones.

Diamonds with mid-range color grades (K through M) will actually look whiter when paired with yellow gold. (White gold or platinum will just accentuate their color).

oval diamond with J color in yellow gold

For this splint shank engagement ring, the customer opted for a J color oval diamond. Since the yellow gold would have added a yellow hue to even the highest (and most expensive) color grades, this was a practical — and beautiful — choice. © CustomMade. Used with permission.

Rose Gold

Diamonds with higher color grades will look off-color in rose gold. Stones with G through J color might look white, but, again, check your ovals against the setting carefully. Using white gold prongs in a rose gold ring may help a high color grade stone appear whiter.

Diamonds with colors K through M may appear white in rose gold, or they could show deeper colors. Only a careful examination against rose gold will tell. Ovals will tend to show deeper colors. Rose gold prongs will help lower color grade stones look whiter, too.

lab-created, oval-cut diamond in rose gold ring

Lab-created, oval-cut diamond, G color, in a 14k rose gold setting. © CustomMade. Used with permission.

Antique Chic

There’s no rule that says you must make your diamond look whiter. If you prefer a white diamond with a little bit of color, go for it. However, if that’s the case, keep in mind that choosing a lower color grade stone will get you what you want for less money. If you like the antique or vintage look, a diamond with deeper color will be perfect for your engagement ring.

Choosing Settings for One-Carat Oval Diamonds

Most oval rings are set vertically, “North-South,” aligned with your finger. This boosts the oval’s “slimming effect” and creates a classic look. However, some people prefer an East-West setting, with the oval’s heads placed perpendicular to the finger. This style is becoming more popular. Ultimately, the choice is yours. Ovals will look great with either orientation.

East-West ring

An East-West oval-cut diamond in a 14k yellow gold, floral halo setting with a scalloped band and milgrain detailing. © CustomMade. Used with permission.

If you’ve chosen a one-carat oval, you’re already getting a stone that will look bigger than a round of the same size. However, the right setting can make your stone appear even bigger. (And if you’ve settled on a stone shy of one carat, this still applies).

0.90-ct oval-cut diamond engagement ring

0.90-ct oval-cut diamond engagement ring. © CustomMade. Used with permission.

Halo

A classic halo setting will surround your oval with smaller diamonds. This will not only add elegance and sparkle but also make the center diamond appear larger. 

Three-Stone

Like the halo, a three-stone setting will help the center stone appear larger. Two smaller side stones, either diamonds or colored gemstones, are placed on either side of the oval.

If you choose a three-stone, halo, pavé, or any other setting that places stones next to your oval, make sure their colors match. At the very least, don’t use side stones with higher color grades than the center stone. Otherwise, your ring might have a very non-harmonious appearance.

three-stone ring, L color oval

The 1-ct oval-cut diamond in this 14k white gold ring has L color, but the baguette side stones have H color, a significantly higher grade than the center stone. This difference, combined with the contrast of the white metal color, highlight the oval’s yellowness. Photo courtesy of liveauctioneers.com and DuMouchelles.

Prongs

There are different ways jewelers can secure your oval to the ring. Prongs are the most common method. Raising the stone away from the band will draw the eye to your oval and also make it look bigger against your finger.

However, keep in mind that prongs can catch on clothing or other objects, which could loosen them. Remove your ring when necessary to avoid damaging it and have a jeweler inspect the prongs at least once a year to make sure they have a secure grip on your stone.

Where Should I Buy a One-Carat Oval Diamond?

Since oval-cut diamonds don’t receive cut grades from gem labs, you simply must examine these stones in person or through an online vendor that provides tools and videos for you to view them in 360°. Both Blue Nile and James Allen make it possible for you to view your diamond this way. Their online tools will also help you examine a stone’s performance, shape, clarity, and color.

If you want something unique, the experts at CustomMade will not only work with you to design the engagement ring but also help you source the perfect oval-cut diamond for your project.

custom-made rose and white gold engagement ring

A custom-made, oval-cut diamond engagement ring with both 14k white and 14k rose gold shanks. © CustomMade. Used with permission.