Square Cut Moissanite: Pros, Cons & Fire

Our Square is a brilliant with a full facet set on a square outline: 69 facets, 65.0% deep, with a 41.39° pavilion. It works as a centre stone or an accent.

Of the square outlines we measure in moissanite, it returns the most light, 82; the Cushion returns 74 and the Radiant Square 71. Against the T73 it still trails on four scores, all by small margins.

Is a square cut good for moissanite? Pros and cons

Pros

Far more fire than in diamond 91 vs 72
Lighter than a diamond square 1.04 vs 1.14 ct

Cons

Loses more light when tipped 88 vs 94
A little less light than the T73 82 vs 86
Slightly more leakage than the T73 11 vs 7
Slightly smaller for its weight 98 vs 100

Compared with the T73 Round Brilliant in moissanite and with the Square Cut 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 Square Cut in moissanite (white) against the T73 Round Brilliant in moissanite (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 moissanite: ahead on 1, level on 1, behind on 6.

Global87, the comparison 91, difference −4
Brilliance82, the comparison 86, difference −4
Fire91, the comparison 97, difference −6
Scintillation78, the comparison 80, difference −2
Spread98, the comparison 100, difference −2
Symmetry100, the comparison 100, difference 0
Shape-norm108, the comparison 93, difference +15
Tilt88, the comparison 94, difference −6

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 moissanite gains in a square cut

Far more fire than in diamond

Fire 91 against 72 for the Square Cut in diamond: 19 points higher

Through the same square plan diamond scores 72 and moissanite 91. Dispersion is the reason: 0.104 for moissanite, 0.044 for diamond.

Square cut in moissanite face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 91) — 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.

Square cut in diamond face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 72) — 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

Lighter than a diamond square

1.04 ct at 6.5 mm, against 1.14 ct for the same cut in diamond (−9%)

At 65.0% deep this is a weighty outline for its width. Moissanite, the less dense material, keeps the carat count down.

A Square Cut 6.5 mm across, weighed from the model's measured volume and each stone's specific gravity.

Try it yourself: Weights in all seven gemstones on the Square Cut page

The catch with a square cut moissanite

Loses more light when tipped

Tilt 88 against 94 for the T73 Round Brilliant in moissanite: 6 points lower

Tipped by 20°, the Square keeps 88 of its face-up light, the T73 94. This is its largest gap to the round.

Square cut in moissanite tilted 0 degrees: Light Return map, 10% 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.

Square cut in moissanite tilted 10 degrees: Light Return map, 14% 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: No square outline we sell beats it on both tilt and light. The Octagon Cut Moissanite keeps 100 when tipped, but returns 67.

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

A little less light than the T73

Brilliance 82 against 86 for the T73 Round Brilliant in moissanite: 4 points lower

82 against 86: close, for a square. Its 41.39° pavilion is steeper than the T73's and above the guide minimum, so steepening is not the fix.

Square cut in moissanite face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 82) — 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 moissanite face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 86) — 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: Among square outlines, none we measure does better in moissanite. Only the rounds go higher, up to 98 for DG-M5 Moissanite.

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

Slightly more leakage than the T73

Leakage 11 against 7 for the T73 Round Brilliant in moissanite: 4 points higher

11% of the light in our census leaves through the pavilion; the T73 loses 7%. A smaller Square would lose the same share.

What helps: At 41.39° the pavilion already clears the 39.5° guide minimum, so a steeper one will not help. DG-Anteros Moissanite leaks 3%.

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

Slightly smaller for its weight

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

A Square of the same carat weight shows a touch less face than the round, because its deep outline holds more weight below the girdle.

Square Cut · 6.41 mm at 1.00 ct · Spread 98

T73 Round Brilliant · 6.68 mm at 1.00 ct · Spread 100

Both stones weigh 1.00 ct in moissanite 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; a 6.5 mm Square weighs 1.04 ct in moissanite.

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

Who a square cut moissanite suits

For a square moissanite with as much light as the outline allows, this is the cut we would pick from our set. It suits a modern solitaire or a row of accent stones.

For more sparkle in a square-ish outline, the Cushion Cut Moissanite scores 85; for the most light, a round such as DG-M5 Moissanite.

Moissanite is doubly refractive, and broad facets can show doubled facet edges. Ours is a brilliant plan, and since the effect is not modelled we cannot score it.

Square Cut Moissanite: questions

Is square cut moissanite bright?

It is the brightest square outline we measure in moissanite, 82, against 86 for the T73 round.

Does square cut moissanite show doubling?

Our renders follow a single refractive index, so they cannot show it. Moissanite's birefringence, 0.043, is real, and cutters usually orient the table to hide it.

What does a 6.5 mm square moissanite weigh?

1.04 ct, against 1.14 ct for a diamond Square of that width.

Get the Square Cut files

6 formatsMillimetresWatertight

Square Cut 3D files

The Square Cut as exact geometry: 69 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

GemCad64 index

Square Cut cutting files

The Square Cut as a faceting design: 57 + 12 girdles = 69 facets, 64 index, 4-fold mirror-image symmetry, ready for the machine.

.ascGemCad design file, 64 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

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

Square Cut Moissanite: the brightest square outline we measure, and fiery