After covering the main polished diamond shapes, it is worth taking a moment to discuss some less common and even esotericdiamond shapes. Some of these shapes, such as Baguettes, are fairly common and serve specific jewelry and setting needs. Others, like the Shield, are created to take advantage of an oddly-shaped rough diamond and turn it into something unique.
Over the past few weeks, we have explained why Rounds are the most common diamond shape. They generally have the highest price per carat. The next group is semi-rounds, also known as Fancy Shape. They include Pear, Oval, Heart and Marquise. Polishing semi-rounds generally takes better advantage of the rough compared to polishing rounds. Most of these shapes have a history that dates back a few centuries, and their values are 30%-60% lower than Rounds with the same weight characteristics.
The third group of diamonds is Squares. They include Cushion, Emerald, Radiant, Asscher and Princess. Some of these shapes have a long history, and some were developed as late as the 1970s. Squares tend to make the most efficient use of the rough diamonds from which they are polished. Thanks to their high yield, they offer some of the best value for their weight.
Some Squares have a wide and open table that requires the use of very high-quality stones, VS and better clarity, while others are great for masking inclusions thanks to their many facets.
The following “alternative” shapes are quite popular, and can be found in the engagement rings and other high-fashion jewelry items of fashionistas and celebrities around the world.
Many diamond shapes are used to enhance and emphasize the center stone in a jewelry item, such as a ring. The trapezoid-shaped Tapered Baguette is one common example used as side stones in rings. They are often set one on each side of the center diamond, with the long side descending along the side of the main ring bar and the narrowest side pointing away from the central diamond. To make sure the ring looks balanced in appearance, it is important to match the two Tapered Baguettes. This matching is known as a “matching pair.”
The Baguettes, as their name implies, are longish rectangles. They are popular for use in watches, where exact sizing is very important. Here too, the wholesaler works hard to create polished diamonds that are as similar to each other as possible, to create matching sets. Baguettes are also found in eternity rings and bracelets. Because of the open table found in both Baguettes and Tapered Baguettes, they do not hide inclusions well, which makes VS clarity or better a requirement.
Creating matching pairs and matching sets adds to the overall value of the diamonds in the set, and exceeds the sum of the value of the individual stones. The reason is that creating matching pairs and sets is a service requiring a lot of work of selecting from a parcel of diamonds many stones, leaving behind goods that don’t match and therefore are more difficult to sell. This is true for all diamond shapes.
The Briolette shape is an unusual one because it does not have a table or a pavilion. It has the shape of a drop, with a heavy bottom and a point at the top. It is a favorite of many diamond connoisseurs, who consider it one of the most beautiful diamond shapes around.
First created in the 15th century, the Briolette is used for earrings and pendants as a dangling item. Although not very common, today the Briolette shape is the choice for some of the most extraordinary diamonds – those that are very large and often with exceptional color. In recent years, the large auction houses have sold several 10 carat and larger Briolette-shaped diamonds that are either D color or fancy color – often pink and yellow.
There is no set number of facets for the Briolette, and polishers tend to increase the number of facets to improve brilliance and light return. A higher degree of whiteness is preferred. Inclusions are relatively hidden, especially as the number of facets rises.
The triangular-shaped Trillion is typically used as a side stone on rings. It is known for its great light refraction qualities and brilliance. As a result, it is used at times as a solitaire.
Trillions have fewer facets than most diamond shapes, around 31-50, and its proportions are important. Because it has few facets, inclusions are easily seen. Some Trillions have three straight edges and others have curved edges.
Trapezoid-shaped diamonds are diamonds used as side stones on rings. It is rare that they are used on their own, and only a handful of diamond manufacturers specialize in polishing them. The Trapezoid is a step-cut, like the Emerald shape and Baguettes. For all these shapes, a higher color is preferred.
The Triangular-shaped diamond has three straight edges of equal length. Like Trapezoid-shaped diamonds, Triangular-shaped diamonds are often used as side stones, although some designers line the geometric shape and use them in large necklaces to create a large, high-brilliance area.
The Shield shape is not found often. It usually has a triangular shape with two or four extra side lines, at times giving it a shape that resembles the side view of a round diamond (which is called a “diamond shape” in popular culture). The decision to polish a Shield is usually dictated by the shape of the rough stone.
Rose Cut diamonds are flat diamonds with very few facets. They have a top and bottom table, and the sides are faceted based on the original shape of the rough to create the widest possible diamond. Rose Cut diamonds are very popular in Indian jewelry designs, and to some degree in the Arab Gulf region. They allow for creating large jewelry items with many diamonds, while reducing both weight and cost if other diamond shapes are used.
Because it is not a standard shape, it lends itself to great creative freedom for designers who will take advantage of the option to make asymmetrical designs, for example. Rose Cut diamonds are mostly used in necklaces and bracelets. Like all flat shapes, inclusions are easily seen.
In addition to the above shapes and the ten shapes mentioned earlier in this series of articles, there are many other diamond shapes. Some are shapes that were invented centuries ago and are not used today because of technological advancements that have improved diamond polishing.
One such shape is the Old Mine, which was popular until the early- to mid-20th century. This shape does not have good light return or brilliance and its yield is rather low. Today, manufacturers prefer polishing round diamonds instead.
Other shapes tend to be unusual creations that take advantage of a very oddly-shaped diamond. They may result in a cross-shaped diamond, a Star of David, a Buddha or even the shape of a horse’s head. When faced with a very oddly-shaped diamond, a polisher may just allow himself to be creative and create a special diamond for a client who appreciates something completely different.
With few exceptions, the use of the shapes mentioned above dictate a lower value compared to the more standard shapes discussed in previous articles. Some of them are so non-standard that they don’t have a standard price. Their price is often a reflection of the cost of the rough diamond they are made from, the cost of polishing and a small premium that reflects how the manufacturer, designer and retailer value the diamond.
The views expressed here are solely those of the author in his private capacity. None of the information made available here shall constitute in any manner an offer or invitation or promotion to buy or to sell diamonds. No one should act upon any opinion or information in this website (including with respect to diamonds values) without consulting a professional qualified adviser.