A GUIDE TO DIAMOND SHAPES
“Diamond shape” refers to the geometric appearance of a diamond and can be categorised into two groups: round brilliant diamonds or fancy shape diamonds. Every diamond is unique and in similar fashion, everyone has their preferred shape.
Diamond Shape vs Diamond Cut?
Whilst a diamond shape can be referred to as its cut, for example “princess cut”, diamond shape is distinct from Diamond Cut - which refers to the facets, symmetry, dimensions and reflective qualities of the diamond. Diamond shape, on the other hand, refers to the external outline or figure of the diamond. For more information on diamond cut, check out our article on The 4Cs of a Diamond.
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We set out below the most popular diamond shapes:
1. Round Brilliant Cut
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The round brilliant cut diamond is by far the most popular diamond shape, representing over two thirds of the diamonds sold.
Consisting of 58 facets (or 57 if the culet is excluded – the sharp pointy tip at the bottom of the diamond), the round brilliant’s shape allows for maximum reflection of light, resulting in its incredible brilliance.
In 1919, Marcel Tolkowsky published his thesis “Diamond Design: A Study of the Reflection and Refraction of Light in Diamond” which explained the ideal angles for a diamond to produce the highest level of brilliance and fire.
2. Oval Cut
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If you are looking for a shape that showcases a similar brilliance and fire to the round cut, but want a slightly more unique shape, you may be interested in the Oval Cut. Created by Lazar Kaplan in the late 1950s, the elongated shape creates the illusion of longer, more slender fingers. As there are no pointed ends, it is a more durable fancy cut if an elongated shape is desired.
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Tips:
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Oval Cut diamonds may exhibit a bowtie - which is a dark area that runs across the centre of the diamond. These are generally more common in oval diamonds that are more elongated with a length to width ratio greater than 1.55 to 1, in excessively deep stones as well as shallow stones.
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A length to width ratio of 1.30 to 1.50 is considered an appealing ratio.
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Oval Cuts are also prone to show colour more easily so it is generally recommended to select a stone with a higher colour grading.
3. Princess Cut
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The Princess Cut is the second most popular diamond shape on the market. Of all the square shapes, it has the most brilliance. These diamonds feature between 57 and 76 facets.
Although the most sought after Princess Cuts are square, pleasing rectangular silhouettes are also available.
Tips:
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A length to width ratio of 1.0 - 1.05 offers a square shape to the naked eye. If a rectangular princess cut is preferred, 1.5 - 2.0 is generally considered an appropriate range.
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When setting a Princess Cut, to prevent damage to corners, it should be set with prongs on all four corners. As the prongs will hide any inclusions on those corners and edges, it is generally considered acceptable to choose a Princess Cut with inclusions towards the edges.
4. Emerald Cut
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Deriving its name from a technique originally designed to cut emeralds, the Emerald Cut consists of a rectangular shape with trimmed corners. Its long, straight lines, known as steps offer an abundance of reflections though sparkle in a more linear manner than the brilliance of a round brilliant.
Tips:
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inclusions may be more noticeable as a result of the large wide facets which allow you to see within the stone. We would thus recommend opting for a higher clarity and colour if choosing the emerald cut.
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the most popular choice of length to width ratio is 1.50 though emerald cuts range from 1.30 to 1.60.
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If you love the shape of an Emerald Cut but are looking more brilliance and fire, you may wish to consider the Radiant Cut.
5. Cushion Cut
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The Cushion Cut gets its name from its pillow-shape with its square or rectangular shape with rounded corners. The Cushion Cut was introduced in the 1800s and has a vintage appeal as they sparkle more like an antique diamond with old-world glamour rather than like a disco ball that is generally exhibited by modern brilliant stones.
Unlike other cuts, the Cushion Cut can be designed in many variations, including as cushion brilliant and cushion modified brilliant.
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Cushion Brilliant: these diamonds have similar faceting arrangements to a Round Brilliant Cut where facets in the pavilion extend from the centre of the diamond out - like a star. Whilst they do not have what is known as a "crushed ice" look, their appeal lies in that they have an appearance like a pillow-shaped Round Brilliant Cut
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Cushion Modified Brilliant: this type of cut is a variation of the Cushion Brilliant. It contains an extra row of facets just below the girdle where the facets are shortened - it resembles more of a flower shop than a star. The Cushion Modified Brilliant has exceptional sparkle that is described "crushed ice" or "sparkling water". You may find these are a little less expensive than brilliant cut diamonds as cutters save more of the diamond when forming them from a rough crystal.
Tip:
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when choosing a cushion cut, be aware that they come in may variations in shape - from square, slightly rectangular to quite rectangular
6. Asscher Cut
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It was created by the Asscher Brothers of Holland’s Asscher Diamond Company (now the Royal Asscher Diamond Company). The Asscher Cut has a similar appearance to the Emerald Cut, featuring large step facets and a high crown that produces a unique brilliance. The sparkle that Asscher Cuts produce is often described as "an endless hallway with reflective mirrors".
Known as a square shape, its four corners are cropped - though these corners are not noticeable once the diamond is set into a four-prong setting.
Tips:
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as a result of the flat table which allow an unobstructed view of the centre of the diamond, inclusions which are visible to the naked eye can likely be seen - as a result you may wish to consider purchasing an Asscher Cut with a higher clarity as as well as a higher colour
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although the Asscher Cut itself does not have a brilliance like some other cuts, you can still get some more sparkle in its setting - for example a halo setting.
7. Radiant Cut
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The Radiant Cut was designed in 1977 by Henry Grossbard in his pursuit to combine a round brilliant cut with an emerald cut. The result was a diamond with 70 facets which created immense brilliance fire - one that is only surpassed by the round brilliant cut. The Radiant Cut is well-known for looking larger than most of the other diamonds of the same carat weight. The face-up area of a Radiant Cut is, in fact, slightly smaller than that of a Round Brilliant of equal carat weight, however, the Radiant Cut's diagonal measurement tricks the eye to make it look larger than it really is.
Tip:
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choose Radiant Cuts with evenly truncated corners. Overly truncated corners will appear off-shape.
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Radiant Cuts come in a wide range of length-to-width ratios. These are a matter of personal preference, however, a length-to-width ratio of 1.15 to 1.35 is usually preferred if looking for a more elongated shape and under 1.05 for square radiants.
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Similar to the Oval Cut, Pear Cut and Marquise-Cut, Radiant Cut diamonds have a bowtie region (a dark band across the centre of the stone). Poorly cut diamonds will show a dark bowtie.
8. Heart Cut
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A clear symbol of love. Due to the complexity of the facets on a heart-shaped gem, it is important to choose a stone that is symmetrical so it appears balanced and full. The cleft (the pointy bit) should be distinct.
Tip:
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An ideal length to width ratio is 1.00. Any lower than this ratio and the heart shape will be appear chubbier. Any higher and the heart will appear more elongated, tall and thing.
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Choose a Heart Shape with a higher carat (1 or 2) to ensure the outline of the heart is most evident.
9. Marquise Cut
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Resembling the shape of an elongated eye, its stunningly large crown makes its wearer's fingers appear longer and more slender. Consisting of 58 facets that come to a dramatic point at each end,
The marquise is another brilliant cut gem with 58 sparkling facets that come to a dramatic point at each end. Similar to oval shapes, the marquise maximizes the look of its carat weight with this stretched out shape. Marquise cuts have the largest surface area of any diamond. The length and pointed ends of a marquise will make fingers appear long and slender.
Tip:
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look for a limited bow-tie effect
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as a result of the long shape, symmetry is importance so choose a Marquise Cut where the two pointed ends align almost perfectly with each other.
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inclusions at the pointed ends are acceptable as two prongs will hold the pointed ends and so any inclusions will likely be hidden by these prongs.
10. Pear Cut
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The Pear Cut is teardrop shaped and is a hybrid of the Round Brilliant Cut and the Marquise Cut. Similar to the Marquise, it elongates its wearer's fingers, making them appear slimmer. When set into a ring, the Pear Cut's pointed end is generally pointed towards the heart of its wearer.
Tips:
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Look for a Pear Cut with good symmetry to ensure brilliance
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The classic length to width ratio range from 1.45 to 1.75.
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Look for the severity of the bowtie (the dark area running across the centre of the diamond)