Asscher Cut Diamond: Pros, Cons & Light Return

Deeply cropped corners turn the Asscher's square into an octagon, and its pavilion falls away in concentric steps. The Asscher we measured has 58 facets and stands 60.4% deep, its stepped pavilion at a shallow 27.6°.

In diamond it wins one score against the T73 Round Brilliant and loses four. A step cut shows the inside of a stone plainly, so it suits stones with good clarity and Art Deco designs.

Is an Asscher cut good for diamond? Pros and cons

Pros

A larger face for its weight 107 vs 100

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 Asscher 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.

Against the T73 Round Brilliant in diamond: ahead on 2, level on 1, behind on 5.

Global78, the comparison 90, difference −12
Brilliance69, the comparison 93, difference −24
Fire80, the comparison 78, difference +2
Scintillation72, the comparison 80, difference −8
Spread107, the comparison 100, difference +7
Symmetry100, the comparison 100, difference 0
Shape-norm91, the comparison 100, difference −9
Tilt79, the comparison 92, difference −13

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 an Asscher cut

A larger face for its weight

Spread 107 against 100 for the T73 Round Brilliant in diamond: 7 points higher

At the same carat weight, the Asscher's outline covers more area than the T73's. A square of a given width holds more face than a circle, and the profile is not deep.

Asscher Cut · 5.89 mm at 1.00 ct · Spread 107

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.

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

Where the Asscher falls short in diamond

Much less light than a round

Brilliance 69 against 93 for the T73 Round Brilliant in diamond: 24 points lower

Its face-up Light Return map shows far more grey than the T73's: a step-cut pavilion offers fewer angles to send light back up. Head-on, the map even shows more grey than the census average, which takes in a wide cone of light.

Asscher cut in diamond face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 69) — 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.

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) — 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: Keep the square but swap the steps for a brilliant plan: the Square Cut Diamond returns 85. With a stepped crown, the Octagon Cut Diamond reaches 71.

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

Loses more light when tipped

Tilt 79 against 92 for the T73 Round Brilliant in diamond: 13 points lower

In the strip the grey grows as the stone tips to 20°, then holds at 30°; the T73's stays far lower at every angle. Tilt is the second-largest gap on this page.

Asscher cut in diamond tilted 0 degrees: Light Return map, 16% of the face leaking — Tilt is how much of its own face-up light a stone keeps when tilted. 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.

Asscher cut in diamond tilted 10 degrees: Light Return map, 19% of the face leaking — Tilt is how much of its own face-up light a stone keeps when tilted. 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: The Octagon Cut Diamond keeps 97 when tipped. We have not measured a steeper Asscher, so we cannot say what different angles would do.

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

More light through the back

Leakage 11 against 2 for the T73 Round Brilliant in diamond: 9 points higher

The Asscher lets 11% of the light out of its pavilion in our census; the T73, 2%. Even face-up, the strip shows grey in the Asscher where the T73 is almost clear.

What helps: Size does not change the share. The Square Cut Diamond loses 10%, DG-Octagonal Kite Diamond 7%.

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

Fewer flashes than a round

Scintillation 72 against 80 for the T73 Round Brilliant in diamond: 8 points lower

A step cut has broad, parallel facets and fewer of them: 58 against the T73's 73. Our scintillation score follows that count.

Asscher Cut · 58 facets · Scintillation 72

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.

What helps: This is the step-cut plan. For a square with more sparkle, the Cushion Cut Diamond scores 85.

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

Who an Asscher cut diamond suits

Choose the Asscher for the step-cut look: broad, mirror-like steps and an octagonal outline, with more face for its weight than a round. Expect far less light than a brilliant, and a stone that darkens as it tips.

For more light in a square, the Square Cut Diamond. The Emerald Square Cut Diamond is the open-table cousin, with more spread (108) and fire but less light (64).

Asscher Cut Diamond: questions

Is an Asscher cut diamond less brilliant than a round?

Yes, by a wide margin in our census: 69 against 93 for the T73 Round Brilliant.

Asscher or emerald square cut diamond?

The Asscher returns more light (69 against 64) and leaks less (11% against 17%); the emerald square has more fire and spread.

Does an Asscher cut diamond look bigger?

At the same carat weight it shows more face: Spread 107 against 100 for the T73 Round Brilliant.

What does a 6.5 mm Asscher diamond weigh?

1.34 ct across a 6.5 mm square: more stone than a round of that width.

Get the Asscher Cut files

6 formatsMillimetresWatertight

Asscher Cut 3D files

The Asscher Cut as exact geometry: 58 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

Asscher Cut cutting files

The Asscher Cut as a faceting design: 58 facets, 96 index, 4-fold 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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Diamond: optical properties and the top ten cuts · The Asscher Cut: specifications, model and files

Asscher Cut Diamond: a larger face for its weight than a round