The Emerald is a classy, clean, architectural diamond shape with a very large fan base. Its large, expansive table draws the eye to look deeply into it. Many of the top-selling diamonds in the world are an Emerald shape.
Most recently, a 100.2-carat Emerald-cut D color, IF clarity diamond sold at Sotheby’s Magnificent Jewels auction for $22.1 million—the most paid for any colorless diamond auctioned in New York. The Annenberg Diamond, a 32.01-carat D flawless, Emerald-shaped diamond, sold for $7.7 million.
High value, Emerald-shaped diamonds are not limited to colorless diamonds. In 2010, a 14.23-carat fancy intense pink diamond of VVS2 clarity was sold for $23.3 million at auction. Sotheby’s also auctioned an 8.74-carat fancy intense blue Emerald-shaped diamond of VVS1 clarity for $5.7 million. In Hong Kong, a pair of Emerald-shaped fancy vivid yellow diamonds weighing 21.17 and 20.77 carats sold for $5 million.
These high numbers and wide range of colors demonstrate that Emerald-shaped diamonds are fit for the highest value diamonds almost regardless of the color of the diamond—blue, pink, yellow or white.
Among the diamond connoisseurs that chose Emerald-shaped diamonds for their engagement rings are Elizabeth Taylor, Grace Kelly, Jennifer Lopez and Sharon Stone.
From Semi-Precious Gem to Diamond
This shape was originally developed for the green semi-precious gem, the emerald, source of the shape’s name. According to several accounts, emeralds tend to have many inclusions and the idea behind this shape was to demonstrate that the gem has few inclusions.
The long parallel facets in the pavilion (the diamond’s lower part) reflect light well. They appear like staircases, which gave this shape the name “step-cut”.
Like the Cushion discussed last week, the Emerald shape is a square diamond shape, one of three groups of diamond shapes. The other two are Rounds and semi rounds – shapes that are based on the Round brilliant, such as the Pear, Oval, Marquise and Heart.
Unlike the Cushion, which has many facets, the Emerald usually has 57 facets (or sometimes 58 facets). Because this shape was designed to draw the eye in for a lingering gaze, polishers will typically choose this shape when they have a long rough diamond that will result in a VS clarity or better.
A Comparison of Round, Oval, Pear, Heart, Marquise, Cushion and Emerald-Shaped Diamonds to Scale
Please note – not real size
Compared to Rounds, the value of Emerald-shaped diamonds is about 29%-58% less, depending on color and clarity. The table below compares the value of one carat and 0.95 carat Emerald-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.
Polishing the Emerald
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 Emeralds, the clarity is very important. Because of its large table, Emerald-shaped diamonds easily disclose inclusions. Therefore, a clarity of VS2 or better is important.
A polisher would usually want 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 4.61-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 1.09-carat, D color and IF clarity. In this case, yield is 23.6%, meaning 76.4% of the rough diamond's weight will be lost in the polishing process.
Alternatively, the manufacturer may polish a larger Emerald-shaped diamond, as shown in the image below. In this case, an Emerald-shaped diamond will take better advantage of the long shape of the rough diamond and will result in a 1.59-carat, D color, IF clarity polished diamond. In this option, the yield is 34.5%.
For this rough diamond, the polisher preferred an Emerald-shape to a Round because of the value. Despite the higher value per carat of Rounds compared to Emeralds, in this case the difference in size is enough to result in a higher value Emerald-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 is a 2.90-carat rough diamond. It can be polished into a 1.10-carat, D/IF Round diamond with an Excellent Cut at a yield of 38%, as shown below.
Alternatively, the polisher may consider an Emerald-shaped diamond, because of the shape of the rough diamond. The polisher can better utilize it to get a higher yield. In this case, a 1.43-carat D/IF, Excellent Cut diamond can be made at a yield of 49.13%, as shown below from a different angle.
As we saw in the article on Cushion-shaped diamonds or Heart-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 Emerald-shaped diamonds. In this case, even though the Round diamond is 23% lighter in weight, it has a higher total value than the alternative Emerald, as the following table shows.
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. Below is a list of Emerald-shaped proportions by Cut standard:
The reason the yield is noted in all these polishing options 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.
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.