Diamond Shapes

The first step in choosing a diamond often involves selecting your favorite (or preferably her favorite) shape.

CUT of a diamond pertains both to the shape of the cut (round, marquise, princess, etc.), and to the make (the quality of the cutting). These are the only factors in diamond grading that are controlled by human hands.

In this lesson, we will talk about the eight major diamond shapes, your first decision when shopping for a diamond. On the next page we will describe a few details about the make of a diamond.


Here is the most extensive list of diamond shapes I have found so far, with photos of each shape. You will be surprised at how many shapes are used around the world, many of which are very hard to find, so don’t get too attached.

The Round Brilliant Cut is by far the most popular shape, and it is the most readily available in every possible quality and size.

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Contrary to popular belief and perhaps your experience in most stores, fancy-shaped diamonds (which is what all non-round diamonds are called) are often less expensive than their round brethren… at the wholesale level.

The Princess Cut as well as the Radiant Cut have been popular in recent years because they are both brilliant and square-ish, as well as one more advantage for the shopper.

These shapes actually save money for a cutter, since it is closest to the octahedral “habit” of rough diamond crystal, the most common formation of diamond in the rough. (The octahedron is like two pyramids base to base, as in the models I created below.)


Here is a rough octahedral crystal fresh from the ground ::


Compared to a Round Brilliant, a cutter can retain more of the original crystal when cutting an octahedron into a Princess shape. The square corners of the rough need to be cut away to create a Round, but they are saved when cutting a Princess.


The more he saves of his original rough crystal, the less the cutter loses on his financial investment in the stone, and therefore you pay less as well. So the square shapes tend to be less expensive than the round.


Here is a photo of a diamond showing the slight bow-tie effect in an oval shape. I angled the light to show it as much as possible in the photo.


Here is a pear shape, which also always have a slight bowtie effect. The less you see it, the better the cut, and usually the more desirable the stone.


But many other shapes can be beautiful if they are cut well, and depending on her taste, for sure. Other fancy shapes include the Marquise Cut, Oval Cut, Pear Shape Cut, Radiant Cut, Heart Shape Cut, Emerald Cut and recently the Cushion Cut and Asscher Cut are popular.

But each of the fancy shapes have an inherent difference in the physics of light. The longer shapes have a slight “bow tie” effect. This means they have a small zone in the center where light leaks out the bottom a little more than other areas of the stone, creating a darker area in the shape of a bow tie. This is especially true for the Pear, Oval, Marquise, and Heart shapes.

The science of cutting a diamond to bring out the full potential of its beauty has developed significantly in the past 10 years. Many diamond cutters now specialize in creating ideal proportions, and such stones have become quite popular. Ideal Cut diamonds command a slight premium because of 1) the extra care and skill needed during cutting, 2) more of the rough is usually cut away, and 3) they are scarce and in high demand.


NEXT :: Diamond Cutting

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