Ready to buy an oval shape diamond? Here’s what you need to know about shopping for oval diamonds. The basics of the 4Cs are the same as for round brilliant diamonds but the GIA grading reports for oval diamonds don’t include a cut grade. (AGS does offer oval cut grades.)
Buyer’s Guide to Oval Shape Diamonds
Oval Shape Diamond Quality Checklist
ROSI looks for diamonds with the best combination of depth and table percentages to reflect the maximum light back to the eye as brilliance. The cut quality of an oval shape depends on its angles and proportions. Large depth and table percentage ranges will include combinations that work well together and combinations that don’t. ROSI eliminates all diamonds that are outside of 58-66 depth percentage and 50-64 table percentage and then chooses combinations of proportions that provide the brightest possible gem. In most cases a depth percentage of 58%-63% is best to avoid a dark bowtie effect. ROSI most often recommends a table percentage of 53%-63%.
The first oval shape diamonds were rose cuts, with triangular facets and a flat back. It wasn’t until the 1700s that the first ovals with brilliant facets were cut. The most famous oval diamond is the 105.60-carat Koh-i-Noor, now in the British Crown Jewels. The Koh-in-Noor, or mountain of light, was first set in the peacock throne of Shah Jahan, the man who built the Taj Mahal. Legend said the owner of the Koh-in-Noor would rule the world, so it’s not surprising that the British demanded it when they colonized India. Queen Victoria had it recut into its current oval shape, losing half its weight but increasing its brilliance and beauty.
It actually wasn’t until 1957 that cutters developed the modern oval cut, with star facets in the back creating brilliance in the center so the entire diamond sparkles with brilliance.
Besides their magical finger-lengthening silhouette, there is a lot to love about oval-shaped diamonds. They have a lot of brilliance and their curved shape means they are very durable, with no points to chip. They lend themselves to almost any engagement ring style, from elaborate vintage settings to sleek modern bezel-set styles.
Just look at a comparison of rings set with 1.25-carat diamonds in six different shapes.
See how big the oval looks in comparison to the round brilliant? It’s as if your diamond magically grew 20 percent in size!
And there’s one more thing we love about oval shape diamonds. They are 10-20 percent cheaper than round brilliant diamonds of the same size and quality. So they look bigger and they cost less? How could you not fall in love with the oval diamond?
A ratio of 1 would be round and a ratio of 1.7 would be longer and skinnier. Which you like best is a matter of personal taste but most people prefer something in the middle.
No matter which shape appeals to you most, there is one important factor to consider in the cut. Almost every oval cut diamond has an optical effect called the “bow tie”: a dark pattern of light across the center of the diamond. The effect can be really obvious in some diamonds and less so in others. Here’s an example of a distracting bow tie.
Buying an oval-shape diamond online can be challenging. That’s why we created ROSI, an artificial intelligence personal shopping tool powered by IBM’s Watson: to sort through all the oval cut diamonds available on the market to find the best balance of quality and value for your budget. See the best oval shape diamond for your budget.
ROSI generally recommends a color of H for an oval shape diamond: J and lower colors will start to show noticeable color on the ends of the oval. Clarity should be at least SI1 (or better whenever possible.) It’s important that an oval shape be symmetrical, with the four quadrants mirror images of each other.
The three diamond shapes that are most similar to an oval cut are the round brilliant, the cushion cut and the marquise shape. The round brilliant is more traditional but it is often brighter, with more brilliance because of its increased symmetry. However you lose the finger-lengthening appeal of the elongated shape of an oval cut. A round brilliant will also look smaller and cost more per carat than an oval shape.
A cushion cut has a similar charm to the oval shape. It is often more brilliant, with cuts like the hearts and arrows Cushion Brilliant diamond, rivaling the brilliance of a round. Although a cushion cut usually has a similar price per carat as an oval shape, it looks a bit smaller to the eye.
A marquise cut is another option for those who love the oval shape. It has a similar finger-lengthening silhouette and large face-up appearance. It often is even less per carat because it isn’t quite as fashionable as the oval shape right now. One drawback to the marquise shape is that the exposed points at each end can chip over the years unless the points are protected in the setting. If you are active or work with your hands, this may limit the style options for a marquise engagement ring.
Our customers’ favorite setting for oval engagement rings is an elegant oval diamond solitaire with a pave band. If you prefer a classic look (hello, Kate Middleton) an oval halo engagement ring has extradiamonds and extra sparkle. A larger floral halo has a vintage vibe. Because the oval cut also lends itself to sleek modern engagement ring styles, a simple bezel-set oval solitaire engagement ring appeals to many minimalist brides. Three stone oval engagement rings most often have round diamonds or tapered baguettes on the sides. Looking for something more unique? Try setting an oval shape diamond east-west across the finger for a twist on a classic.