Encyclopedia · Shapes & cuts
Cushion cut
By Diamond BrosUpdated 4 min read
What is a cushion cut diamond?
The modern cushion brilliant is a square or squarish-rectangular shape with curved sides and either rounded or pointed corners. It is faceted as a brilliant, typically with four or eight kite-shaped main facets running from the girdle to the culet.
It comes in two styles: a cushion brilliant and a modified cushion brilliant, which has extra facets on the crown or pavilion. Gem-A classes the cushion as a modified brilliant variant.
Where does the cushion cut come from?
The cushion is one of the oldest diamond shapes and cutting styles. Its forerunner is the old mine cut of the 1700s, which was the most common cut until the late 19th century. An old mine cut has a squarish shape with a high crown, small table, deep pavilion and large culet. It was named for the Brazilian diamond mines, because it suited the shape of the rough found there.
A modern cushion is cut to different proportions, but it keeps the soft, squarish outline. The old European cut is the antique round style often mentioned alongside it.
What is the crushed ice look?
Modified brilliant cushions create a "crushed ice" effect, meaning the extra facets break the light into many small flashes, like shards of ice. A standard cushion brilliant has fewer facets. Neither is better; the facet pattern is a matter of taste, so look at the actual diamond.
What applies to both: GIA's advice is not to expect the sparkle of a round brilliant or a princess. The appeal is the soft shape and the vintage feel.
Does a cushion look smaller, and what ratio should it have?
A cushion can appear smaller than other shapes of the same carat weight, though it typically costs less per carat than a round brilliant. Compare the length and width in millimetres, not just carats.
The GIA guides listed below give no preferred length-to-width ratio for cushions, which run from square to rectangular, so choose the outline you like. GIA does ask you to check symmetry: the sides and corners should mirror each other in the amount of curve, to avoid an off-shape outline.
| Style | Key features | Look |
|---|---|---|
| Old mine cut | High crown, small table, deep pavilion, large culet | Antique and squarish, from the 1700s |
| Cushion brilliant | Four or eight main kite-shaped facets | Soft outline, more open facets |
| Modified cushion brilliant | Extra facets on crown or pavilion | Crushed ice effect |
How do you protect a cushion cut's girdle?
The girdle of a cushion is thicker at the corners than between them, and an extremely thin girdle can be vulnerable to chipping. To protect it, consider a bezel setting rather than prongs. If you prefer prongs or a halo for the look, ask how the girdle will be protected.
GIA does not give an overall cut grade to cushions, so a report lists polish and symmetry; AGS Laboratories says it has extended its cut grading to cushions.
Is a cushion cut right for you?
It suits a softer, vintage-leaning look. The trade-off is a different pattern of sparkle from a round, and the facet pattern differs between a cushion brilliant and a modified one. See the diamond shapes guide for the full comparison.
To look at one, visit a showroom. A custom engagement ring can be designed around a cushion, and you can browse engagement rings for ideas.
Key takeaways
- A cushion cut has a square or rectangular outline with curved sides and rounded corners.
- GIA traces it to the old mine cut of the 1700s, the most common cut until the late 19th century.
- Modified cushion brilliants have extra facets that give a crushed ice effect.
- Do not expect the sparkle of a round or princess; a cushion can also look smaller for its weight.
- The girdle is thicker at the corners, and a very thin one is vulnerable to chipping, so consider a bezel.
Common questions
What is the difference between a cushion cut and an old mine cut?
The old mine cut is the antique forerunner, from the 1700s, with a high crown, small table, deep pavilion and large culet. A modern cushion is a brilliant-style cut with its own proportions. They share the soft, squarish outline, so a modern cushion gives a similar shape in a newly cut stone.
Is a cushion cut as sparkly as a round diamond?
No. Do not expect the sparkle of a round brilliant or a princess cut. A modified cushion with extra facets gives a crushed ice effect, which is lively in a different way. Look at the stone in person.
Why can a cushion cut look small for its carat weight?
Cushion cuts can appear smaller than other shapes of the same carat weight. Carat weight measures mass, not the area you see from above. Compare the millimetre measurements of the stones you are weighing up.
Are cushion cut diamonds fragile?
Not especially, but chipping is the concern. The girdle is thicker at the corners than between them, and an extremely thin girdle is vulnerable to chipping. Consider a bezel setting rather than prongs. Ask the jeweller to check the girdle before you buy.
What is a modified cushion brilliant?
It is a cushion cut with extra facets added to the crown or the pavilion. The added facets create a crushed ice appearance. A standard cushion brilliant has fewer facets.
Sources
- Cushion cut diamond: old, new, classicGIA · 4cs.gia.edu
- Guide to diamond shapes for engagement ringsGIA · 4cs.gia.edu
- Six things to know about GIA diamond cut gradesGIA · 4cs.gia.edu
- Beginner's guide: the 8 most popular diamond cuts and shapesGem-A · gem-a.com
- Light Performance Series: What is light performance?American Gem Society · americangemsociety.org
Related guides
- Diamond shapes: every shape comparedCompare ten diamond shapes by apparent size, sparkle, length-to-width ratio and weak points, then match a shape to your hand and setting.
- Engagement ring settings: solitaire, halo, pavé and moreThe setting decides how safely your diamond is held, how much light reaches it, what upkeep the ring needs and which wedding band will sit beside it.
Related terms
- Old European cutAn old European cut is an antique round diamond with 58 facets, a high crown, a relatively small table, a deep pavilion and a visible culet.
- Princess cutA princess cut is a square diamond cut in a modified brilliant style, so it keeps a lively, sparkly face despite its sharp corners.
- Round brilliant cutA round brilliant cut is a circular diamond with 57 or 58 facets, arranged to send as much light as possible back to your eye.
- Halo settingA halo setting surrounds a centre stone with a ring of smaller accent stones.
- Bezel settingA bezel setting holds a stone with a thin strip of metal that wraps around its edge, called the girdle.
- Carat weightCarat weight is how much a gemstone weighs. One metric carat is exactly 200 milligrams (0.2 g), divided into 100 points of 2 mg each.
- Oval cutAn oval cut is a brilliant-cut diamond with an elliptical outline.
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