Cushion Cut Diamond: finer sparkle than a modern round, in a soft square

Brilliance 80 · Fire 73 · Scintillation 85 · in our census, where the T73 scores 93 · 78 · 80 in diamond

A square with rounded corners and a brilliant plan: more sparkle than the T73, less light, less fire, and a little less face for its weight.

See it in the simulatorGet the files
The Cushion Cut in diamond, rendered at an angle in our 3D Gemstone Simulator under studio light
Rendered in our 3D Gemstone Simulator from the Cushion Cut model, 1.00 ct, studio light.

Cushion Cut Diamond

Our cushion is the modern one: rounded corners on a square outline, a full brilliant plan, and a line of descent from the old mine cut. We measured a cushion of 85 facets, 65.0% deep, with its pavilion at 39.56°.

Against the T73 Round Brilliant it wins one score and loses four. Against the antique cushions it does much better: in diamond it returns more light than the Peruzzi Cut Diamond (75) or the Old Mine Cut Diamond (59), and leaks far less. It also holds its light when tipped as well as the T73, 92 against 92.

Is a cushion cut good for diamond? Pros and cons

Pros

Cons

Compared with the T73 Round Brilliant in diamond. A difference counts from 3 points (Brilliance, Fire, Tilt, Leakage), 5 (Scintillation, Symmetry), 2 (Spread) or 5% (weight); Tilt counts as a pro only for a stone within 5 points of the brilliance it is compared with. How we measure.

All eight scores against the T73

At a glance: the Cushion Cut in diamond (white) against the T73 Round Brilliant in diamond (dashed): solid white where it reaches further, hatched where it falls short. Each pro and con is explained, with pictures, below.

Performance wheel: Cushion Cut in diamond, against the T73 Round Brilliant in diamond as an outline. Solid white marks where it reaches further, hatching where it falls short. The scores are listed below.50100Global−6Brilliance−13Fire−5Scintillation+5Spread−2Symmetry−3Shape-norm−7Tilt0

Against the T73 Round Brilliant in diamond: ahead on 1, level on 1, behind on 6.

  • Global84, the comparison 90, difference −6
  • Brilliance80, the comparison 93, difference −13
  • Fire73, the comparison 78, difference −5
  • Scintillation85, the comparison 80, difference +5
  • Spread98, the comparison 100, difference −2
  • Symmetry97, the comparison 100, difference −3
  • Shape-norm93, the comparison 100, difference −7
  • Tilt92, the comparison 92, difference 0
Face-up light census, a different measure from the Cut Grading Tool; Spread and Shape-norm above 100 sit on the ring.
Open it in the Cut Performance Wheel

What diamond gains in a cushion cut

More scintillation than the T73

Scintillation 85 against 80 for the T73 Round Brilliant in diamond: 5 points higher

With 85 facets against the T73's 73, it has more surfaces to flash as it moves. The margin is at our threshold, so it counts, but only just.

Cushion Cut · 85 facets · Scintillation 85

T73 Round Brilliant · 73 facets · Scintillation 80

Scintillation follows the number of facets: more facets, more and smaller flashes as the stone moves. Count the facets in each crown. Drawn from each cut's own model.

Try it yourself: Compare the Scintillation spoke in the Cut Performance Wheel

Where the cushion falls short in diamond

Less light than a round

Brilliance 80 against 93 for the T73 Round Brilliant in diamond: 13 points lower

A square outline puts corners where a round has none, and the census returns 80 against 93. It is still the most light of any cushion we measure.

Cushion cut in diamond face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 80)

Cushion Cut in diamond · Brilliance 80

T73 round brilliant in diamond face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 93)

T73 Round Brilliant in diamond · Brilliance 93

Red, green and blue = light returning to the eye; grey = light leaving through the pavilion. This is the head-on view; the Brilliance score averages a wider cone of light, so the score can differ from what one picture shows.

What helps: For a squarish outline with more light, the Square Cut Diamond returns 85 and DG-Octagonal Kite Diamond 88.

Try it yourself: Open this Light Return map in the simulator

More light through the back

Leakage 9 against 2 for the T73 Round Brilliant in diamond: 7 points higher

Around a tenth of the cushion's light, 9%, leaks from the pavilion in our census, to the T73's 2%. Its 39.56° pavilion is above diamond's 38.9° guide minimum, so the angle is not the cause our data points to.

Cushion Cut in diamond · Leakage 9

Cushion cut in diamond tilted 0 degrees: Light Return map, 16% of the face leaking0° · 16% leak
Cushion cut in diamond tilted 10 degrees: Light Return map, 8% of the face leaking10° · 8% leak
Cushion cut in diamond tilted 20 degrees: Light Return map, 14% of the face leaking20° · 14% leak
Cushion cut in diamond tilted 30 degrees: Light Return map, 22% of the face leaking30° · 22% leak

T73 Round Brilliant in diamond · Leakage 2

T73 round brilliant in diamond tilted 0 degrees: Light Return map, 4% of the face leaking0° · 4% leak
T73 round brilliant in diamond tilted 10 degrees: Light Return map, 2% of the face leaking10° · 2% leak
T73 round brilliant in diamond tilted 20 degrees: Light Return map, 9% of the face leaking20° · 9% leak
T73 round brilliant in diamond tilted 30 degrees: Light Return map, 14% of the face leaking30° · 14% leak
Each frame is the Light Return map with the stone tilted away from you by the angle shown; grey is light leaving through the pavilion. The share under each frame is that picture's own.

What helps: Not by steepening the pavilion. A smaller stone leaks the same share; DG-Octagonal Kite Diamond leaks 7%.

Try it yourself: Tilt it yourself in the simulator's light map

A little less fire

Fire 73 against 78 for the T73 Round Brilliant in diamond: 5 points lower

Fire 73 against 78: the light that returns carries slightly less colour than a round's.

Cushion cut in diamond face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 73)

Cushion Cut in diamond · Fire 73

T73 round brilliant in diamond face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 78)

T73 Round Brilliant in diamond · Fire 78

Look at the coloured flashes: those are fire. Same light, same size, same face-up angle; rendered by our 3D Gemstone Simulator from each cut's own model.

What helps: DG-Octagonal Kite Diamond gives a compact, eight-sided outline with Fire 82.

Try it yourself: See the fire in the 3D Gemstone Simulator

A touch smaller for its weight

Spread 98 against 100 for the T73 Round Brilliant in diamond: 2 points lower

At 65.0% deep, it carries more of its weight below the girdle, so a cushion of a given carat weight shows a little less face than a T73.

Cushion Cut · 6.01 mm at 1.00 ct · Spread 98

T73 Round Brilliant · 6.48 mm at 1.00 ct · Spread 100

Both stones weigh 1.00 ct in diamond and are drawn to the same scale, from each cut's own model. Spread is face-up size per carat: a deeper stone carries more weight below the girdle and looks smaller for its weight.

What helps: Choose by millimetres rather than carats: a 6.5 mm cushion is 1.27 ct.

Try it yourself: Compare the Spread spoke in the Cut Performance Wheel

Who a cushion cut diamond suits

Choose the cushion for a soft, square diamond that sparkles a little more than a round and holds its light when tipped. Of the cushions we measure in diamond it is clearly the one to pick. It suits vintage-style rings.

If you want more light in a square, the Square Cut Diamond; for a symmetrical eight-sided stone with more fire, DG-Octagonal Kite Diamond. For the antique version of the outline, compare the Peruzzi Cut Diamond.

Cushion Cut Diamond: questions

Is a cushion cut diamond less brilliant than a round?

Yes: Brilliance 80 against 93 for the T73 Round Brilliant, with 9% of the light leaking against 2%.

Does a cushion cut diamond sparkle more than a round?

A little: Scintillation 85 against 80, just past our threshold.

Modern cushion or Old Mine cut diamond?

The modern cushion, for light: Brilliance 80 against 59, leakage 9% against 32%.

What does a 6.5 mm cushion cut diamond weigh?

About 1.27 ct, more than a round of that width: the square outline and deep profile hold more stone.

Get the Cushion Cut files

6 formatsMillimetresWatertight

Cushion Cut 3D files

The Cushion Cut as exact geometry: 85 planar facets, real-world scale, ready for CAD, rendering, printing and casting.

  • STEPExact faceted solid for CAD
  • 3DMRhino, closed mesh on its own layer
  • STLWatertight mesh for printing and casting
  • OBJMesh for modelling and rendering
  • FBXBlender, 3ds Max, Maya, Cinema 4D, Unity, Unreal
  • GLBWeb, AR and quick previews
€9.99 · Personal useBuy the 3D files
GemCad96 index

Cushion Cut cutting files

The Cushion Cut as a faceting design: 69 + 16 girdles = 85 facets, 96 index, 2-fold mirror-image symmetry, ready for the machine.

  • .ascGemCad design file, 96 index gear
  • .csvTier table: angles, indices and cutting order
  • DiagramPrintable faceting diagram
€9.99 · Personal useBuy the cutting files

Questions before you buy? Email us.

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