Hexagon Cut Diamond: Pros, Cons & Fire

The hexagon sets a step-cut crown over a tiered pavilion on a six-sided outline, between a step cut and a brilliant in character. The model we measured has 37 facets and stands 61.0% deep over a shallow 29.26° pavilion.

Against the T73 Round Brilliant in diamond it gains on fire and loses on brilliance, scintillation, leakage and, narrowly, face-up size. Its Tilt reads 100; we do not count it, because its brilliance is far below the round's.

The Octagon Cut Diamond carries the same tier profile on eight sides. In diamond they divide the honours: the octagon returns more light, the hexagon more fire.

Is a hexagon cut good for diamond? Pros and cons

Pros

More fire than a round 85 vs 78

Cons

Much less light than a round 58 vs 93
Fewer flashes than a round 56 vs 80
Nearly a quarter of the light leaks 24 vs 2
Slightly smaller for its weight 96 vs 100

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 Hexagon 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 2, behind on 4.

Global76, the comparison 90, difference −14
Brilliance58, the comparison 93, difference −35
Fire85, the comparison 78, difference +7
Scintillation56, the comparison 80, difference −24
Spread100, the comparison 100, difference 0
Symmetry100, the comparison 100, difference 0
Shape-norm77, the comparison 100, difference −23
Tilt100, the comparison 92, difference +8

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 hexagon cut

More fire than a round

Fire 85 against 78 for the T73 Round Brilliant in diamond: 7 points higher

Of the light that comes back, more is split into colour than in the T73. It also beats the octagon, which scores 76 on the same tier profile.

Hexagon cut in diamond face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 85) — 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 hexagon's costs in diamond

Much less light than a round

Brilliance 58 against 93 for the T73 Round Brilliant in diamond: 35 points lower

The pavilion figure is a shallow 29.26°, well below the 38.9° guide minimum we use for round designs, though still above diamond's 24.4° critical angle. We have not measured a steeper hexagon.

Hexagon cut in diamond face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 58) — 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 Octagon Cut Diamond keeps the stepped crown and returns 71; for far more, a round such as the T73 Round Brilliant Diamond.

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

Fewer flashes than a round

Scintillation 56 against 80 for the T73 Round Brilliant in diamond: 24 points lower

37 facets against 73: a step crown and a plain pavilion give the census few surfaces to count. Only four cuts we measure score lower in diamond.

Hexagon Cut · 37 facets · Scintillation 56

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 plan sets it. The Octagon Cut Diamond reaches 66 with more facets on the same profile.

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

Nearly a quarter of the light leaks

Leakage 24 against 2 for the T73 Round Brilliant in diamond: 22 points higher

The census loses 24% of the hexagon's light through the back, against 2% for the T73. The octagon, with the same profile, loses 18%.

Hexagon cut in diamond tilted 0 degrees: Light Return map, 30% 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.

Hexagon cut in diamond tilted 10 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.

What helps: The share holds at any size. The Octagon Cut Diamond loses 18%.

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

Slightly smaller for its weight

Face-up size 96 against 100 for the T73 Round Brilliant in diamond (T73 = 100): 4% less face-up area for the same weight

The gap sits at our threshold: at the same carat weight its outline covers a little less area than the T73's. A 6.5 mm hexagon weighs 1.29 ct, more than a round of that width.

Hexagon Cut · 6.90 x 5.97 mm at 1.00 ct · Face-up size 96

T73 Round Brilliant · 6.48 mm at 1.00 ct · Face-up size 100

Both stones weigh 1.00 ct in diamond and are drawn to the same scale in millimetres, from each cut's own model. Face-up size is the outline's area per carat, with the T73 at 100: a deeper stone, or a rounder outline, spreads less area for its weight.

What helps: Compare stones by millimetres rather than carats.

Try it yourself: See its size at 1.00 ct in diamond in the 3D Gemstone Simulator

Who a hexagon cut diamond suits

Choose the hexagon for geometric designs, clusters and bands where six sides tile neatly, and where a high Fire score counts for more than brilliance.

For more light with a stepped crown, the Octagon Cut Diamond. If light comes first, a round: DG-Vitruvio Diamond returns 93 with fire of 79.

Hexagon Cut Diamond: questions

Is a hexagon cut diamond brilliant?

Not very: Brilliance 58 against 93 for the T73, with 24% of the light leaking.

Hexagon or octagon cut diamond?

The octagon returns more light (71 against 58) and leaks less (18%); the hexagon has more fire (85 against 76).

Does a hexagon diamond have good fire?

It does: the census puts its fire at 85, where the T73 Round Brilliant scores 78.

What does a 6.5 mm hexagon diamond weigh?

1.29 ct. A regular hexagon is 1.155 times as long point to point as it is across the flats.

Get the Hexagon Cut files

6 formatsMillimetresWatertight

Hexagon Cut 3D files

The Hexagon Cut as exact geometry: 37 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

Hexagon Cut cutting files

The Hexagon Cut as a faceting design: 31 + 6 girdles = 37 facets, 96 index, 6-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 Hexagon Cut: specifications, model and files

Hexagon Cut Diamond: more fire than a round, in six straight sides