Square Cut Cubic Zirconia: Pros, Cons & Fire

Our square brilliant carries a full facet set on a square outline, the square counterpart of the round. The model has 69 facets, a 41.39° pavilion and is 65.0% deep.

In CZ and in diamond it returns the same light, 85. CZ adds fire. The T73 in CZ returns far more light, and that gap is what this page is mostly about.

Is a square cut worth it in cubic zirconia? Pros and cons

Pros

More fire than the diamond square 83 vs 72

Cons

Much heavier than diamond 1.88 vs 1.14 ct
Less light than the T73 in CZ 85 vs 98
Light lost through the pavilion 11 vs 1
Slightly smaller for its weight 98 vs 100

Compared with the T73 Round Brilliant in cubic zirconia 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 cubic zirconia (white) against the T73 Round Brilliant in cubic zirconia (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 cubic zirconia: ahead on 2, level on 1, behind on 5.

Global86, the comparison 93, difference −7
Brilliance85, the comparison 98, difference −13
Fire83, the comparison 87, difference −4
Scintillation78, the comparison 80, difference −2
Spread98, the comparison 100, difference −2
Symmetry100, the comparison 100, difference 0
Shape-norm111, the comparison 106, difference +5
Tilt88, the comparison 87, difference +1

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 the square cut gives cubic zirconia

More fire than the diamond square

Fire 83 against 72 for the Square Cut in diamond: 11 points higher

Diamond splits light at 0.044, CZ at 0.060, so the square's flashes carry more colour in CZ. It stays a few points under the T73 in CZ, 87.

Square cut in cubic zirconia face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 83) — 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

The catch with a square cut CZ

Much heavier than diamond

1.88 ct at 6.5 mm, against 1.14 ct for the same cut in diamond (+65%)

Deep and dense: at 6.5 mm the square weighs 1.88 ct in CZ, where the diamond weighs 1.14 ct.

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

What helps: Order it by size, not weight.

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

Less light than the T73 in CZ

Brilliance 85 against 98 for the T73 Round Brilliant in cubic zirconia: 13 points lower

The square returns in CZ what it returns in diamond, no more. The T73 gains in CZ and the square does not, which opens the gap.

Square cut in cubic zirconia face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 85) — 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 cubic zirconia face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 98) — 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 in CZ, the Cushion Cut Cubic Zirconia returns 88 and DG-Octagonal Kite Cubic Zirconia 93.

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

Light lost through the pavilion

Leakage 11 against 1 for the T73 Round Brilliant in cubic zirconia: 10 points higher

11% in our census, against 1% for the T73 in CZ and 10% for the diamond square. At 41.39° the pavilion clears the 38.1° guide minimum, so a steeper one is not our answer.

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

Square cut in cubic zirconia tilted 10 degrees: Light Return map, 12% 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: Size changes nothing here. DG-Octagonal Kite Cubic Zirconia leaks 5% in CZ.

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 cubic zirconia: 2 points lower

At 65.0% deep, a square of a given carat weight is a touch narrower than the T73. The outlines drawn at 1 ct show how small the difference is.

Square Cut · 5.27 mm at 1.00 ct · Spread 98

T73 Round Brilliant · 5.49 mm at 1.00 ct · Spread 100

Both stones weigh 1.00 ct in cubic zirconia 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; spread matters only when buying by carat.

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

Who a square cut CZ suits

The square suits a CZ meant as a versatile centre or accent stone with a modern square outline and plenty of colour.

For more light with straight sides, DG-Octagonal Kite Cubic Zirconia; for a softer square, the Cushion Cut Cubic Zirconia; for sharp corners and the most colour of our squares, the Princess Cut Cubic Zirconia at 92 for fire.

Against the square in diamond, the CZ is level on light, ahead on fire, and holds its light a little better when tipped: 88 against 86.

Square Cut Cubic Zirconia: questions

Is a square cut good for CZ?

It is a fair choice: Fire 83 and Brilliance 85, against 87 and 98 for the T73 in CZ.

Square or princess cut in CZ?

The square returns more light (85 against 63) and leaks less (11% against 22%). The princess has more fire, 92 against 83.

Square CZ or square diamond?

The light is the same (85 in diamond); CZ has more fire, 83 against 72. Diamond is far lighter and harder.

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

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

Square Cut Cubic Zirconia: more fire than the same square in diamond