Last updated on August 3, 2021
Classic round cut diamonds have always been the most popular of all diamond shapes. However, there is also an increasing interest in oval cut diamonds as they look both classy and unique. Although these two cuts share some traits, several features set them apart. Let’s discover the differences between round cut vs oval cut diamonds and see what aspects to consider when choosing between the two.
What Is a Round Cut Diamond?
The history of round cut diamonds, also referred to as round brilliant cut diamonds, traces back to the middle of the 17th century when diamond cutters began using more refined and complex techniques.
The early brilliant cut, also known as the Mazarin cut, after Cardinal Mazarin, was created in 1650. In the early 18th century, through gradual transformations and developments, this cut gave birth to such unique cuts as Peruzzi, Old Mine and Old European cut.
The modern round brilliant cut was created by Russian mathematician and diamond enthusiast Marcel Tolkowsky in 1919. This cut is also sometimes referred to as the Tolkowsky cut, after its creator. It features 58 or 57 facets if the culet is pointed.
The round brilliant cut is the world’s most sought after diamond cut due to its timeless style and unparalleled brilliance and sparkle. The round cut is also the standard by which all other diamond cuts are measured.
What Is an Oval Cut Diamond?
Oval cut diamonds belong to the family of fancy shaped diamonds, and they have a long history, undergoing many changes since their early years.
The modern brilliant oval cut has 57 or 58 facets and was created by a Russian-born diamond cutter Lazare Kaplan in 1957. Before inventing the modern oval cut, Kaplan was mastering his skills in cleaving, a process in which cracked or heavily included diamonds are cut into smaller, less included stones. In other words, he was working with diamonds that other cutters considered “worthless” turning them into gorgeous stones. However, his talent was not fully recognized until he designed the modern oval cut.
The elongated shape of oval cut diamonds gives them an illusion of higher carat weight. The most appealing length to width ratio for oval diamonds is usually between 1.30 – 1.50. Stones with a lower ratio may look too round, while diamonds with a higher ratio resemble the marquise cut.
Round Cut vs Oval Cut Diamonds
Round cut diamonds always feature a round shape. They differ visually one from another in terms of size but never in shape. Whereas oval diamonds have an elongated shape, which provides a slimming effect for the fingers of the wearer, and come in a variety of length to width ratios.
Each fancy diamond cut has a certain length to width ratio that is considered most appealing for that shape. While personal preference prevails, the optimal ratio for oval cut diamonds is between 1.30 – 1.50. The higher the ratio, the thinner an oval diamond looks.
Cut and Facets
Both the round and oval cut diamonds belong to the brilliant-cut group. This means their facets are arranged in a way to maximize a stone’s brilliance and sparkle.
While both cuts have the same number of facets, the difference in diamond shapes creates a difference in the forms of their facets. Oval diamonds have larger facets, while round diamonds feature smaller ones.
Due to its facet pattern, an average 1-carat oval diamond has a 10% larger surface area than a round diamond of the same carat weight.
Brilliance and Sparkle
The round cut is the most brilliant of all diamond cuts. Its concentrated shape and faceting structure allow producing maximum fire, brilliance and scintillation.
The oval cut is very close to the round cut in terms of brilliance and sparkle but since it has larger facets its sparkle may seem to appear neater. However, oval cut diamonds are one of the most brilliant cuts available on the market.
Colour and Clarity
Brilliant cuts tend to hide imperfections in a diamond, due to their facet arrangement and light performance. Since both round and oval cut diamonds belong to the brilliant-cut group, there is no significant difference between them in terms of clarity.
However, keep in mind that oval diamonds show more colour because of their shallower cut, so you might want a higher colour grade. This is especially true for larger stones (0.50 ct >).
Round cut diamonds never have a bowtie, while elongated shapes like oval, pear and marquise typically do.
Most oval cut diamonds exhibit a bowtie effect, which occurs when some of the light at the centre leaks and does not bounce back to the table.
Sometimes the bowtie effect in oval diamonds is easily noticeable, and other times it is hardly visible. The truth is that a prominent bowtie effect distracts from the beauty of the stone, which is why you should make sure the diamond you choose does not have a dominant bowtie, meaning it is not the first thing you see when looking at an oval cut diamond.
Price and Availability
Due to their elongated shape oval diamonds tend to be more affordable, as much as 30% less expensive, than round cut diamonds because diamond cutters cut away less of the original rough than they would when cutting a round diamond. Another reason is that oval diamonds are less in demand than round diamonds. So if you are on a budget, the oval cut is a better option.
Since oval diamonds are less in demand, they are also rarer and less available compared to round diamonds, especially if you are looking for exact specifications.