Cut registry › Jewellery cuts › Cushion
Jewellery cuts · Fancy brilliant
The pillow cut.
Of the twenty-one jewellery cuts we measure, the cushion places second, and its real buying decision appears on no certificate at all.
The short version
A cushion cut diamond is a square or rectangular brilliant with rounded corners and curved sides, giving it the pillow outline it is named for, typically 58 to 64 facets.
Its most important variable is not on any grading report: whether it is faceted as a chunky cushion or a crushed ice cushion, which changes the whole character of the stone.
Definition
The cushion has been in production, in one form or another, longer than the round brilliant. Its ancestor is the old mine cut, the standard shape of the eighteenth and nineteenth centuries, which had the same rounded-square outline cut for candlelight rather than for electric light.
Modern cushions divide into two families. A chunky cushion has fewer, larger facets that you can follow with your eye, and it produces bold, readable flashes. A crushed ice cushion carries many small pavilion facets that scatter light into a glittering, shattered texture with no pattern in it at all.
No certificate distinguishes the two. Prices overlap. Neither is objectively better, and the choice between them is the single largest thing you will decide about a cushion. It can only be made on video or in person.
The clarity consequence follows directly. A crushed ice cushion scatters light so thoroughly that inclusions disappear into the texture, so you can safely buy lower. A chunky cushion opens large, calm windows into the stone, and anything inside them is visible.
Proportions
Commonly cited ranges against our measured reference stone. Two of the numbers below are thresholds rather than preferences, and they are worth remembering.
| Measure | Commonly cited | Our reference stone | What it does |
|---|---|---|---|
| Length-to-width | 1.00 to 1.05 square; 1.10 to 1.30 rectangular | 1.00 | Purely a matter of outline preference. |
| Depth | 61% to 68% | 65.0% | Above about 70% the stone leaks and can go nail-headed. |
| Table | 58% to 68% | 54.9% | Above about 73% the stone starts to window. |
| Pavilion angle | not commonly published | 42.6° | Decides whether light returns or escapes. |
| Facets | 58 to 64 | 85 | Counted as facets that actually reach the surface. |
GIA issues no cut-quality grade for cushions. Nor does any report record whether a cushion is chunky or crushed ice, which is the variable that will decide whether you like the stone. Judge that on moving footage, not on paper.
Light
The same census that measures every cut on this site: 3,200 rays face-up, 2,200 at 20° tilt, on exact facet geometry, against T57 as the standard.
| Material | Useful light | Leak | Fire | Scintillation | Global | vs the standard |
|---|---|---|---|---|---|---|
| Diamond | 79.83% | 9.31% | 73.28 | 84.88 | 83.68 | −4.92 |
| Moissanite | 73.92% | 12.33% | 92.71 | 84.88 | 85.18 | −4.64 |
| Cubic zirconia | 87.75% | 6.67% | 86.81 | 84.88 | 88.34 | −3.43 |
| T57 standard, diamond | 92.28% | 1.88% | 78.85 | 71.82 | 88.61 | 0.00 |
Our reference cushion returns 79.83% of entering light usefully and leaks 9.31%, for 83.68 Global against the standard’s 88.61. The gap of 4.92 points is the smallest of any jewellery cut we publish. If you want a fancy shape and you do not want to give up much light to get it, this is the measured answer.
It carries 85 active facets for 84.88 on scintillation, well above the standard’s 71.82. That facet count is what produces the cushion’s soft, busy, slightly diffuse sparkle rather than the round brilliant’s sharper pattern.
Its light is also unusually evenly spread. Across five bands from one side to the other our reference cushion varies by only 2.5 points, against 1.0 for the round-brilliant control and 41.2 for the oval. A cushion has no dark ends, because it has no ends.
Where the light is: useful return across the stone
Five equal bands across the outline, each returning ray binned by where it leaves the crown. A cushion is close to symmetrical in both axes, so the profile is nearly flat, and that flatness is one of the shape’s underrated virtues.
Against the standard
Light return. 92.28% for the round against 79.83% for the cushion. The round still wins, but by 4.92 points of Global this is the closest any fancy shape here comes.
Sparkle character. 85 facets against 57, so the cushion scores 84.88 on scintillation against 71.82. It produces more separate flashes than a round brilliant, but softer ones, which is why cushions read as warm where rounds read as bright.
Fire. 73.28 against the standard’s 78.85. The cushion’s reputation for throwing colour is not folklore.
Durability. The rounded corners are the best-protected of any square-ish shape. A cushion needs no special setting, unlike a princess.
Price. Generally less per carat than a comparable round.
The baseline for all of this is the round brilliant itself. Its facet plan is set out in the anatomy of a round brilliant, and the measured standard we compare against is T57, the stone Tolkowsky published in 1919.
Materials
In moissanite the cushion returns 73.92% for 85.18 Global, with fire at 92.71. It remains the strongest jewellery cut in that material too, which suggests the result belongs to the shape rather than to any one refractive index.
In cubic zirconia it returns 87.75% for 88.34 Global, leaking only 6.67%, the lowest leak figure of any jewellery cut we measure in any material.
Compare all three for this shape in the Index.
Trade-offs
Questions
The questions buyers actually ask, answered in full. Where the answer is ours to prove, the figure is measured on the Index; where it is an established gemological fact, it is stated as one.
A cushion cut diamond is a square or rectangular brilliant with rounded corners and gently curved sides, resembling a pillow, and typically carrying 58 to 64 facets. It descends from the old mine cut, the standard diamond shape of the eighteenth and nineteenth centuries.
A chunky cushion has fewer, larger facets that the eye can follow, producing bold and readable flashes. A crushed ice cushion has many small pavilion facets that scatter light into a shattered, glittering texture with no pattern. No grading report records which one you are looking at, prices overlap, and neither is objectively better. Judge it on video or in person.
The commonly cited ranges are 61% to 68% depth and 58% to 68% table. Two thresholds matter more than the ranges: above roughly 70% depth a cushion leaks light and can look nail-headed, and above roughly 73% table it begins to window, appearing transparent rather than reflective. Our reference cushion sits at 65.0% depth and 54.9% table.
No. GIA issues cut grades for round brilliants only, so a cushion report carries symmetry and polish but no assessment of light performance. It also does not record whether the stone is chunky or crushed ice.
It produces more separate flashes and less returned light. Our reference cushion scores 84.88 on scintillation against the round brilliant’s 71.82, because it carries more facets, but it returns 79.83% of entering light against 92.28%. In practice a cushion reads softer and busier, a round reads brighter and sharper.
Around 1.00 to 1.05 for a square cushion and 1.10 to 1.30 for a rectangular one. Unlike the marquise, where ratio has a measurable optical effect, this is an outline preference and nothing more.
It depends entirely on the facet style, which is why the crushed ice question comes first. Crushed ice scatters light thoroughly and hides inclusions well, so you can buy lower with confidence. Chunky cushions open large calm windows into the stone and show what is inside them.
Yes, and more so than any other square or rectangular shape. The rounded corners remove the exposed points that make princess cuts vulnerable, so a cushion needs no protective setting.
Generally yes, per carat, at comparable colour and clarity, because the shape retains more of the original rough than a round does.
Structurally, the cushion’s rounded corners are safer than the princess’s sharp ones, which sit on cleavage planes and need V-prongs to protect them. Optically we measure the cushion at 83.68 Global and the princess at 76.20, on identical protocol. The cushion’s light is also far more evenly spread: it varies by 2.5 points across its face where the princess varies by 25.5, because a princess measurably darkens at its corners.
Next
See the whole set on the jewellery cuts index, or the measured house and historic cuts in the cut registry.
Method
Monte-Carlo on exact facet geometry: 3,200 rays face-up plus 2,200 at 20° tilt, cosine-weighted from a 7° near-vertical cone. Useful light is what exits through the crown within 64° of vertical. The same protocol runs on every cut on this site, so the figures are comparable to each other.
They measure our reference geometry for the shape at the proportions listed above, not an average of stones on the market. A cushion cut to different proportions will read differently. Treat them as a like-for-like comparison between shapes, not as a grade for any individual stone.
Engine estimates, ±2 points, not lab-certified grades. We do not publish the Index symmetry axis on these pages: it scores facet regularity within each pavilion family, which is meaningful for a round brilliant and misleading for a shape whose pavilion is deliberately irregular.
84.88 here against the standard’s 71.82. The term is 100(1−e−n/45) on the count of facets that actually reach the surface, so it is a pure function of facet count and nothing else.