Princess Cut Diamond: Pros, Cons & Light Return

The princess is a square brilliant with sharp corners, its pavilion cut in chevrons. Our model has 85 facets in its cutting design, a 41.94° pavilion and a depth of 68.5%.

Against the T73 Round Brilliant it gains on fire and loses on brilliance, leakage and tilt. Scintillation, symmetry and face-up size are close to the round's.

Among square outlines in diamond it returns the least light we measure: the Square Cut Diamond returns 85, the Radiant Square Cut Diamond 72 and the Asscher Cut Diamond 69.

Is a princess cut diamond a good choice? Pros and cons

Pros

A little more fire than a round 83 vs 78

Cons

Much less light than a round 57 vs 93
Nearly a fifth of the light leaks 18 vs 2
Keeps a little less light when tipped 89 vs 92

Compared with the T73 Round Brilliant in diamond. A difference counts from 3 points (Brilliance, Fire, Tilt, Leakage), 5 (Scintillation, Symmetry), 4% (face-up size per carat) 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 Princess 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 1, level on 1, behind on 6.

Global76, the comparison 90, difference −14
Brilliance57, the comparison 93, difference −36
Fire83, the comparison 78, difference +5
Scintillation78, the comparison 80, difference −2
Spread95, the comparison 100, difference −5
Symmetry100, the comparison 100, difference 0
Shape-norm89, the comparison 100, difference −11
Tilt89, the comparison 92, difference −3

Face-up light census, a different measure from the Cut Grading Tool; Spread and Shape-norm above 100 sit on the ring. Spread is the census's estimate from depth alone; the face-up size in the pros and cons is measured from each model's outline.

Open it in the Cut Performance Wheel

What diamond gains in a princess cut

A little more fire than a round

Fire 83 against 78 for the T73 Round Brilliant in diamond: 5 points higher

The margin clears our threshold without much to spare. It is the most fire of the square brilliants we measure in diamond: the square reaches 72, the cushion 73. Among square outlines only the emerald square, a step cut, shows more.

Princess cut in diamond 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.

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 princess cut's costs in diamond

Much less light than a round

Brilliance 57 against 93 for the T73 Round Brilliant in diamond: 36 points lower

About a quarter of the princess's face is grey in the head-on map, against a sliver in the T73's. Its 41.94° pavilion is steeper than the 38.9° guide minimum.

Princess cut in diamond face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 57) — 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: For more light in a square, the Square Cut Diamond returns 85; with cropped corners, the Radiant Square Cut Diamond returns 72.

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

Nearly a fifth of the light leaks

Leakage 18 against 2 for the T73 Round Brilliant in diamond: 16 points higher

18% of the light leaves through the princess's pavilion in our census; the T73 loses 2%. In the strip the grey stays at about a quarter of the face up to 20° and grows at 30°.

Princess cut in diamond tilted 0 degrees: Light Return map, 25% 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.

Princess cut in diamond tilted 10 degrees: Light Return map, 24% 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: Not by steepening: the pavilion already sits above diamond's guide minimum, and the share is the same at any size. The Square Cut Diamond loses 10%.

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

Keeps a little less light when tipped

Tilt 89 against 92 for the T73 Round Brilliant in diamond: 3 points lower

The gap is the smallest a con can be on our scale: 89 against 92 at 20°. The strip barely changes until 30° because it traces light straight down; the census sends a slightly fanned beam, and that is where most of the gap comes from.

What helps: Our data points to rounds for this: DG-Rafaello Diamond keeps 97 when tipped.

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

Who a princess cut diamond suits

Choose the princess for a square diamond with sharp corners and a slightly higher Fire score than a round, from far less light. The corners are its weak points, and a setter usually protects them with V-prongs.

If light matters more than the sharp corners, the Square Cut Diamond returns far more and leaks less. For softened corners and more light, the Radiant Square Cut Diamond, though with less fire (62).

Princess Cut Diamond: questions

Is a princess cut diamond as brilliant as a round?

No. Brilliance 57 against 93 for the T73 Round Brilliant, and 18% of the light leaking against 2%.

Does a princess cut sparkle more than other square diamonds?

More than some, not all: its scintillation, 78, is level with the square brilliant's 78 and below the cushion's 85, but above the radiant square's 66 and the Asscher's 72.

Princess or square cut diamond?

The square for light (85 against 57) and less leakage (10% against 18%). The princess scores more fire (83 against 72), but from far less light.

What does a 6.5 mm princess cut diamond weigh?

1.48 ct, well above a T73 of that width.

Get the Princess Cut files

6 formatsMillimetresWatertight

Princess Cut 3D files

The Princess Cut as exact geometry: 93 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

Princess Cut cutting files

The Princess Cut as a faceting design: 81 + 4 girdles = 85 facets, 96 index, 4-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.

More gemstones and cuts

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

Princess Cut Diamond: more fire than a round, in a sharp-cornered square