Emerald Square Cut Diamond: Pros & Cons

Take the emerald cut's concentric steps and cropped corners, set them on a square, and you have the emerald square. Its 49 facets sit on a model 61.0% deep, with the pavilion steps at a shallow 28.16°.

It is close in spirit to the Asscher. In diamond the two split the difference: the emerald square has more spread and fire, the Asscher Cut Diamond more light (69 against 64) and less leakage.

Is an emerald square cut good for diamond? Pros and cons

Cons

Much less light than a round 64 vs 93
More light through the back 17 vs 2
Darkens more when tipped 79 vs 92
Fewer flashes than a round 72 vs 80

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 Emerald Square 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.

Global76, the comparison 90, difference −14
Brilliance64, the comparison 93, difference −29
Fire84, the comparison 78, difference +6
Scintillation72, the comparison 80, difference −8
Spread108, the comparison 100, difference +8
Symmetry100, the comparison 100, difference 0
Shape-norm84, the comparison 100, difference −16
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 emerald square cut

A larger face for its weight

Spread 108 against 100 for the T73 Round Brilliant in diamond: 8 points higher

Only one cut we measure in diamond shows more face at the same carat weight. A square with cropped corners covers more area than a circle of the same width, and the profile is not deep.

Emerald Square Cut · 5.73 mm at 1.00 ct · Spread 108

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

More fire than the T73

Fire 84 against 78 for the T73 Round Brilliant in diamond: 6 points higher

Long, straight step facets send light out in broad flashes that separate into colour. The margin over the T73 is clear.

Emerald square cut in diamond face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 84) — 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.

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) — 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.

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

The emerald square's costs in diamond

Much less light than a round

Brilliance 64 against 93 for the T73 Round Brilliant in diamond: 29 points lower

Step facets are broad and parallel, and fewer of them face the eye at the angles that return light. In our census it trails the T73 by nearly a third.

Emerald square cut in diamond face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 64) — 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: The Asscher Cut Diamond returns 69 with a similar look; the Square Cut Diamond 85 as a brilliant.

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

More light through the back

Leakage 17 against 2 for the T73 Round Brilliant in diamond: 15 points higher

The census counts 17% of the light lost out of the back of the emerald square, where the T73 loses 2%. The 28.16° pavilion figure sits well below the 38.9° guide minimum we use for rounds, and we have not measured a steeper version.

Emerald square cut in diamond tilted 0 degrees: Light Return map, 20% of the face leaking — 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.

Emerald square cut in diamond tilted 10 degrees: Light Return map, 27% of the face leaking — 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: A smaller stone leaks the same share. The Asscher Cut Diamond loses 11%.

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

Darkens more when tipped

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

At 20° it keeps 79 of its face-up light, against 92 for the T73: the same as the Asscher.

What helps: For a stepped crown that holds its light at an angle, the Octagon Cut Diamond keeps 97.

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

Fewer flashes than a round

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

Step cuts carry fewer facets, 49 here against 73, and our scintillation score follows the count.

Emerald Square Cut · 49 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: The step plan sets this; the Cushion Cut Diamond reaches 85 with a brilliant plan.

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

Who an emerald square diamond suits

Choose the emerald square for a clean, architectural square with plenty of face for its weight and more colour than a round. It suits centre stones and earrings. In diamond it returns much less light than a brilliant and darkens as it tips.

If light matters more, the Asscher Cut Diamond is the closer step cut and the Square Cut Diamond the brilliant one. For spread and fire in three sides, the Trillion Cut Diamond.

Emerald Square Cut Diamond: questions

Does an emerald square cut diamond look big for its weight?

Yes: Spread 108 against 100 for the T73, the second-largest we measure in diamond.

Is an emerald square cut diamond fiery?

More than a round: Fire 84 against 78.

Emerald square or Asscher for a diamond?

The Asscher for light (69 against 64); the emerald square for spread and fire (84 against 80).

What does a 6.5 mm emerald square diamond weigh?

1.46 ct: heavier at that width than the Asscher, because less of the square is cropped away.

Get the Emerald Square Cut files

6 formatsMillimetresWatertight

Emerald Square Cut 3D files

The Emerald Square Cut as exact geometry: 49 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

Emerald Square Cut cutting files

The Emerald Square Cut as a faceting design: 41 + 8 girdles = 49 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.

More gemstones and cuts

Diamond: optical properties and the top ten cuts · The Emerald Square Cut: specifications, model and files

Emerald Square Cut Diamond: the second-largest face for its weight we measure, with extra fire