The price of a diamond is determined by many different factors, including size, proportion, quality, shape, rarity, and desirability in the current marketplace. Out of all of these factors, there are three that tend to affect the diamond price the most: carat weight, cut grade, and shape. Carat weight, which reflects a diamond’s size, has a very straightforward impact on diamond price. Most people know that larger diamonds will come with steeper price tags. However, there’s less public understanding of how and why cut grade and shape can have such a major impact on diamond price. 

As a jeweler that specializes in diamond jewelry, people often ask us, “what’s the most expensive diamond cut?” It’s actually hard to answer this question straight on, since people are sometimes asking about diamond cut grade, but they may also be asking about diamond shape. Diamond cut and diamond shape are often confused for one another, but they’re distinctly different elements of diamonds. However, no matter which you’re wondering about, we’re here to answer your question. Below, we’re going over the difference between diamond cut and diamond shape, then sharing the most expensive diamond cut and the most expensive diamond shape. 

Diamond Cut vs. Diamond Shape 

Diamond cut and diamond shape are both very important to the look of a diamond, albeit in very different ways. 

Diamond shape is the shape that a rough diamond has been cut into, such as round, princess, pear, emerald, oval, asscher, and so on. Diamond shape doesn’t affect diamond quality, but it does have a defining effect on a diamond’s style. For example, round cut diamonds have a classic style, emerald cut diamonds have a retro vintage style, and princess cut diamonds have a modern style. 

While diamond shape describes the shape a diamond has been cut into, diamond cut is a grading of how well a diamond was cut into its shape. Alongside carat weight, color grade, and clarity grade, diamond cut grade is one of the 4Cs. And, according to many diamond experts, diamond cut is the most important of the 4Cs, since it has the biggest overall impact on a diamond’s beauty. Well-cut diamonds will look symmetrical and will sparkle beautifully, as their cut won’t allow much light leakage. Poorly cut diamonds, on the other hand, will look dull and dim, and they may have prominent issues in their faceting and symmetry. 

The Most Expensive Diamond Cut Grade: Excellent 

The Gemological Institute of America (GIA) has five potential gradings for a diamond cut. From best to worst, they are Excellent, Very Good, Good, Fair, and Poor. As you may imagine, the best of these, Excellent, is the most expensive option. 

While Excellent cut diamonds are certainly gorgeous, opting for this very expensive cut grade isn’t always necessary to get a beautiful diamond. If you’re looking to maximize your budget, Very Good cut diamonds are a good alternative option, since they’ll still shine brightly enough to look beautiful in important pieces like engagement rings. To the naked eye, Very Good cut diamonds may even look similar to Excellent cut diamonds. Then, Good cut diamonds are another option that still has good brilliance and sparkle, so they can be an attractive budget pick. Beyond these three grades, however, buyers should beware. Fair and Poor cut diamonds can look quite dim and lifeless. So much so that many jewelers do not even bother carrying them. 

The Most Expensive Diamond Shape: Round Brilliant 

There’s one diamond shape that’s markedly more expensive than the rest: round. Round diamonds are more expensive for two reasons. One is the cost involved in creating a round-cut diamond from a rough stone. Creating this detailed, perfectly round shape requires a highly skilled diamond cutter and it leads to more rough diamond waste compared to other shapes, so it’s more expensive to manufacture a round diamond. The other reason round cut diamonds are more expensive is that they’re just extraordinarily popular, so people charge more for them due to market demand. Round brilliant-cut diamonds, loved for their incredible light performance and classic style, make up more than 50% of all diamonds sold today. Round is the most popular diamond shape by far, which contributes to it also being the most expensive diamond shape by far.

Assuming carat weight and qualities are the same, round brilliant cut diamonds are always more expensive than fancy shaped diamonds. If you’re unfamiliar with the term “fancy shaped” it’s a category that includes every gemstone shape other than round. Examples of fancy shaped diamonds include emerald cut, oval cut, pear shape, marquise cut, heart shape, princess cut, radiant cut, asscher cut, and cushion cut diamonds. 

On average, a round brilliant cut diamond will cost around 20% to 30% more than a fancy cut diamond. This means that those who have their heart set on a round diamond for their jewelry may have to pay a premium to get the look they love. Yet, it also means that those who are drawn to fancy shaped diamonds could get more of a bargain. This is especially true for elongated shapes, like oval and emerald cut, which look larger per carat on top of having a lower price per carat. 

So, if you’re looking for ways to maximize your diamond engagement ring or diamond jewelry budget, don’t forget to consider a gorgeous fancy-shaped diamond for your center stone. And if an elongated fancy shape would be the perfect diamond for you, all the better!