Marquise A Royal Diamond

The Marquise is an elongated diamond shape with a large top surface. As such, it is a great choice when size is a leading factor in choosing a diamond shape. 

The story behind the Marquise-shaped diamond dates back to the 18th century, when King Louis XV of France wanted a diamond shaped after the lips of his lead mistress, Jeanne Antoinette Poisson, Marquise de Pompadour. He commissioned the court jewelers to create a jewelry item set with the diamonds as a present, according to legend.

Much celebrity-generated attention surrounded the diamond shape when actor Michael Douglas gave Catherine Zeta-Jones a Marquise-shaped diamond engagement ring. Singer-turned-fashion designer Victoria Beckham wears a Marquise-shaped diamond that she received from her husband, star footballer David Beckham—a ring that has earned many mentions in the British and international press. 

Also referred to as “Navette,” French for little boat, the Marquise-shaped diamond is a member of the semi-round diamond shapes – those that are based on the Round brilliant, such as the Pear-shape, Oval and Heart. It has 58 facets.

A Comparison of Round, Oval, Pear, Heart, and Marquise-Shaped Diamonds to Scale 

^{Please note – not real size}

Compared to Rounds, the value of Marquise-shaped diamonds is about 21%-56% less, depending on color and clarity. The table below compares the value of one carat and 0.95 carat Marquise-shaped diamonds, to 1-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.

Value of Marquise-Shaped Diamonds Compared to 1 ct Round Diamonds

Polishing the Marquise

Polishers will create a Marquise-shaped diamond when the rough dictates it. Typically, a long rough diamond is an ideal candidate for a marquise. However, rough diamonds in models that are ideal for Marquise-shaped diamonds are uncommon. As with other semi-round shapes (also known as “fancy”), the Marquise may suffer from a light effect known as a “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. The bow tie, which can vary from hardly visible to severe, can be eliminated by adding a French culet, a facet replacing the culet.

The Best Shape for the Most Value

When considering rough diamonds for polishing, a manufacturer is usually faced with a number of alternatives to choose from. First, he has to take into account that with the marquise, its exact proportions and faceting are very important. Unless a Very Good Cut or better, a Marquise-shaped diamond will not reflect light well. In addition, in lower colors, the color tends to concentrate at the edges of the polished marquise. This leads jewelers to hide the tips, at least partially, when setting in a jewelry item.

In most cases, a polisher wants to get the best value out of a rough diamond. Consider the choices a polisher faces in the following two real-life examples. First, a 2.28-carat rough diamond is pictured in the 3D render below. The polisher can polish out of it a Round diamond, which will result in a 0.74-carat, D color, IF clarity and Excellent Cut. In this case, the yield is just 32.5%, meaning 67.5% of the rough diamond's weight will be lost in the polishing process.

^{Image: Sarine}

Alternatively, the polisher may decide to take advantage of the elongated shape of this rough diamond, and polish a Marquise-shaped diamond, as shown in the image below. In this case, it will result in a 1.02-carat, D color, IF clarity and Excellent Cut polished diamond and a much more efficient 44.8% yield.

^{Image: Sarine}

In this rough diamond, the polisher preferred a Marquise shape to a Round because of the value. Despite the higher value per carat of Rounds compared to Marquises, the difference in size results in a higher value Marquise-shaped diamond. The value comparison below is based on an analysis of current prices in the market and represents the total value of the diamonds.

In the next example, a 4.68-carat rough diamond can be polished into a 1.35-carat, D/IF Round diamond with an Excellent Cut at a yield of 28.9%.

^{Image: Sarine}

Alternatively, the polisher may want to consider a Marquise-shaped diamond. Once again, the rough diamond has a longish shape, which will result in a higher yield. A 1.70-carats D/IF, Excellent Cut diamond can be made, at a yield of 36.5%, as shown below.

_{Image: Sarine}

As we saw in the article on Pear-shaped diamonds, Heart-shaped diamonds and Oval-shaped diamonds, even if the optional Round diamond is smaller than the alternative shape, the Round may still have a higher total value. This is true for all shapes, including the Marquise. Even though the Round diamond is smaller, it has a higher value than the alternative Marquise, as the following table shows.

With this rough diamond model, a second round diamond is at times possible—which would further tilt the choice in favor of a Round. 

The reason the yield is noted 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 different options, and seeing which is more economically beneficial to manufacture.

Necessary Proportions

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 must enter through the top of the diamond, bounce inside of it and then reflect out through the top. The more light that is reflected, the more the diamond shines.

To achieve this, the facets must face each other at the right angles. Because of the unique properties of the Marquise shape, the proportions and exact angles of the facets are of particular importance. Below is a list of Marquise-shaped 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 varying characteristics of diamonds that may seem identical but differ enough to affect their value.

In addition, we presented a table that showed the difference in value between the various diamond 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.

The views expressed here are solely those of the author in his private capacity. No one should act upon any opinion or information in this website without consulting a professional qualified adviser.