Oval-shaped diamonds are another member of the semi-round diamond shapes - those that are based on the round brilliant, but with a twist. Unlike the Pear-shape, discussed last week, which is half of a round on one end and a Marquee on the other, the oval is a somewhat elongated round as the name suggests, which gives it the appearance of larger than it really is. 

A Comparison of Oval, Pear and Round-Shape Diamonds to Scale

- not real size

Some of the most beautiful diamonds in history are Oval shape, such as the Koh-I-Noor, which belongs to Queen Elizabeth II, and the 184-carat Victoria, which was cut in 1887. In recent years, Oval-shape diamonds grabbed headlines for their prices. Among them were a 118.28 carat D color, Flawless diamond that sold for a record breaking $30.6 million at Sotheby's in Hong Kong and the 'Princie', a 34.65-carat pink diamond, which sold for $39.3 million at Christie's New York in 2013, at the time a record price for a Golconda diamond at auction.

Recently, a number of celebrity musicians and actresses flashed engagement rings set with Oval-shape diamonds, including Blake Lively, Amber Rose and Katie Holmes, proving that the diamond has a wide appeal and that it works very well as a single or center stone on a ring.

Like rounds and Pears, the Oval-shaped diamond usually has 58 facets. Also like Pears, some Oval-shaped diamonds have a light effect known as "bow tie," a dark area in the diamond. It is the result of light not bouncing back up to the face of the diamond because of a misalignment of facets and can vary from hardly visible to severe.

Because of the large table (the top surface of the diamond) of the Oval-shaped diamond, it is very easy to look into it, even with an untrained eye. Because of that, inclusions are easier to see, especially if the diamond's clarity is I (Inclusion). Because of that, it is hard to hide an inclusion with a smart setting, which means that there is a strong preference for high quality Oval-shape diamonds.

Compared to Rounds, the value of Oval-shape diamonds are about 17%-42% less than rounds, depending on color and clarity, just like Pear-shaped diamonds.

The table below compares the value of 1 carat and 0.95 carat Oval-shape diamonds to one carat round diamonds (1 carat round = 100%) in all colors and clarities. The 0.95-carat comparison is here to highlight the relatively small difference in size that results in a large difference in value.

The table below compares the value of 1 carat and 0.95 carat Oval-shape diamonds to one carat round diamonds (1 carat round = 100%) in all colors and clarities. The 0.95-carat comparison is here to highlight the relatively small difference in size that results in a large difference in value.

Polishing Ovals (Courtesy: Sarine)

When considering rough diamonds for polishing, a manufacturer is usually faced with a number of alternatives from which to choose. In the 3D render below is a 4.15-carat rough diamond. The polisher can polish out of it either a Round or an Oval-shaped diamond.

If a round diamond is picked, it will result in a 1.11-carat round, resulting in a 27% yield, meaning 73% of the rough diamond's weight will be lost in the polishing process.

 Alternatively, the manufacturer may decide to polish an Oval-shaped, shown in the image below. In this case, it will result in a 1.50-carat polished diamond, a 36% yield.

 The reason the yield is pointed out here is because from a financial standpoint, it makes sense to try to get the best return out of the cost of the rough diamond. Given the two different possible outcomes, it is worth comparing the value of the two options, and see which is more economically beneficial to manufacture.

After examining the polishing options, it is clear that despite the higher value per carat of Rounds compared to Ovals, the difference in weight is great enough to result in an Oval-shape diamond that has a higher value than the Round diamond that can be polished out of this rough diamond. The value comparison above is based on an analysis of current prices in the market and represents the total value of the diamonds.

In the below example, is a 3.72-carat rough diamond that can be polished into a 1.24-carat Round shape diamond (on the left) or into a 1.50-carat Oval (o the right). In the first case, the yield is 33.4% and in the second, 39.5%.

As we saw in the article on Pear-shape diamonds, sometimes even if the optional round diamond is smaller than the alternative shape, it may still have a higher total value. This is true for all shapes, including Ovals. In this case, even though the Round diamond is smaller, it has a higher value than the alternative Oval, as the following table shows.

Another consideration is clarity. Sometimes in one situation an inclusion will be included in the polished diamond, and with a different shape the inclusion will not be included. This may have a noticeable impact on the value of the diamond and will be one of the considerations a polisher will take into account.


When polishing a diamond, proportions are important for a number of reasons, including aesthetics. A well-proportioned diamond looks much better than one that is not. Another reason is light return. To get the best light return light enters from the top of the diamond, bounces inside of it, and then out through the top. The more light that is reflected the more the diamond "shines."

To achieve that, the facets must face each other in the right angles. Below is a list of Oval-shape proportions by Cut standard:

 As stated in previous articles, the intention of this review is to highlight a number of issues relating to diamonds, their value and how to understand the differing characteristics of diamonds that may seem identical but differ enough to impact their value.

In addition, in the context of shapes, we presented a table that showed the difference in value between the various shapes. This table is part of the Mercury Crystal Clear™ system. It is important to keep it in mind when considering diamonds as part of a wealth preservation belief or even as a gift.

No one should act upon any opinion or information in this website without consulting a professional qualified adviser.