Hexagon Cut Almandine: what our light census measures

Brilliance 66 · Fire 68 · Scintillation 56 · in our census, where the T73 scores 95 · 54 · 80 in almandine

How the Hexagon Cut handles light in almandine, measured: brilliance 66, fire 68 and 23% leakage, set against the T73 in the same stone and against the same cut in diamond.

The Hexagon Cut in almandine, face-up Light Return map from our tracer at refractive index 1.75: red, green and blue show where the light returns from, gray shows where it leaks
Light Return map of the Hexagon Cut in almandine, face-up, from our own tracer at refractive index 1.75. Red, green and blue return light to the eye; gray leaks.

Hexagon Cut Almandine

Almandine has a refractive index of 1.750 to 1.830 and a dispersion of 0.027. Its critical angle, from the low end of that range, is 34.8°, so a round design needs a pavilion of at least 36.3° for head-on light to reflect off both sides of the pavilion and leave through the table. We trace it with one index, 1.790, the midpoint of the published range, and a fire spread of 0.023, 0.86 of the published dispersion. Every picture here is our Light Return tracer at 1.750, and every figure is from the same light census that scores the other gemstones; the 3D Gemstone Simulator shows the Hexagon Cut in almandine live.

The Hexagon Cut has 37 facets and a total depth of 61.0% of its width; its pavilion mains sit at 29.3°. In almandine, the census returns 66 of 100 for brilliance and 68 for fire, against 95 and 54 for the T73, our benchmark, in the same stone; the same Hexagon Cut in diamond reads 58 and 85.

Is almandine good in a Hexagon? Pros and cons, measured

Compared with the T73 Round Brilliant in almandine and with the Hexagon Cut 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 almandine (white) against the T73 Round Brilliant in almandine (dashed): solid white where it reaches further, hatched where it falls short. Each pro and con is explained, with pictures, below.

Performance wheel: Hexagon Cut in almandine, against the T73 Round Brilliant in almandine as an outline. Solid white marks where it reaches further, hatching where it falls short. The scores are listed below.50100Global−8Brilliance−29Fire+14Scintillation−24Spread0Symmetry0Shape-norm−15Tilt+19

Against the T73 Round Brilliant in almandine: ahead on 2, level on 2, behind on 4.

  • Global75, the comparison 83, difference −8
  • Brilliance66, the comparison 95, difference −29
  • Fire68, the comparison 54, difference +14
  • Scintillation56, the comparison 80, difference −24
  • Spread100, the comparison 100, difference 0
  • Symmetry100, the comparison 100, difference 0
  • Shape-norm87, the comparison 102, difference −15
  • Tilt96, the comparison 77, difference +19
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; these are the same census figures as our Cut Performance Index.

What the Hexagon Cut gains in almandine

Against the T73 in almandine and the same cut in diamond, no figure of the Hexagon Cut is ahead by the thresholds above. Its figures are in the wheel and the FAQ; Almandine ranks every cut we score in almandine.

What the Hexagon Cut gives up in almandine

Returns less light than the T73 in almandine

Brilliance 66 against 95 for the T73 Round Brilliant in almandine: 29 points lower

Brilliance is the share of the 3,200 census rays that enter the stone and come back out of the crown towards the viewer. In almandine, whose critical angle is 34.8°, the Hexagon Cut returns 66 of 100 and the T73 95. The Hexagon Cut's pavilion mains sit at 29.3°, the T73's at 40.8°. The maps below show where each stone's light returns from and where it leaks.

Hexagon cut in almandine face-up Light Return map: red, green and blue show where the light returns from, gray shows where it leaks (Brilliance 66)

Hexagon Cut in almandine · Brilliance 66

T73 round brilliant in almandine face-up Light Return map: red, green and blue show where the light returns from, gray shows where it leaks (Brilliance 95)

T73 Round Brilliant in almandine · Brilliance 95

Red, green and blue = light returning to the eye; gray = leakage, light that leaves heading down or stays inside. 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 DG-M5 reads 99 for brilliance in almandine, the best of the cuts we score there.

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

Fewer facets, less sparkle

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

Scintillation follows the number of facets the stone shows: 100 × (1 − e^(−facets / 45)). The Hexagon Cut has 37 facets and the T73 73, so 56 against 80. It depends on the geometry alone, so it is the same in every stone.

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. Compare the facet counts under the drawings; each drawing shows only the crown. Drawn from each cut's own model.

What helps: the DG-Miliano reads 98 for scintillation in almandine, the best of the cuts we score there.

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

Leaks more light than the T73 in almandine

Leakage 23 against 5 for the T73 Round Brilliant in almandine: 18 points higher

Leakage is the share of the census rays that enter the stone and leave through the pavilion, or through the crown heading down. The Hexagon Cut leaks 23% in almandine against 5% for the T73 in almandine. Grey in the maps below is leaking light; the share under each picture is that picture's own.

Hexagon Cut in almandine · Leakage 23

Hexagon cut in almandine tilted 0 degrees: Light Return map, 21% of the face leaking0° · 21% leak
Hexagon cut in almandine tilted 10 degrees: Light Return map, 26% of the face leaking10° · 26% leak
Hexagon cut in almandine tilted 20 degrees: Light Return map, 29% of the face leaking20° · 29% leak
Hexagon cut in almandine tilted 30 degrees: Light Return map, 30% of the face leaking30° · 30% leak

T73 Round Brilliant in almandine · Leakage 5

T73 round brilliant in almandine tilted 0 degrees: Light Return map, 1% of the face leaking0° · 1% leak
T73 round brilliant in almandine tilted 10 degrees: Light Return map, 10% of the face leaking10° · 10% leak
T73 round brilliant in almandine tilted 20 degrees: Light Return map, 28% of the face leaking20° · 28% leak
T73 round brilliant in almandine tilted 30 degrees: Light Return map, 30% of the face leaking30° · 30% leak
Each frame is the Light Return map with the stone tilted away from you by the angle shown; gray is leakage. The share under each frame is that picture's own.

What helps: the DG-M5 reads 1% for leakage in almandine, the best of the cuts we score there.

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

Less fire in almandine than in diamond

Fire 68 against 85 for the Hexagon Cut in diamond: 17 points lower

Fire is the share of the returned light that splits into color at the exit facet: the census traces each exit again at the refractive index minus and plus the fire spread (0.023 in almandine) and counts a ray as fire when the two directions differ by more than 0.6°. The Hexagon Cut reads 68 against 85 for the same cut in diamond. The figure is the census's; the 3D Gemstone Simulator renders almandine's fire live.

The fire figure is the census's, traced at the refractive index minus and plus the fire spread. See the fire in the 3D Gemstone Simulator: the Hexagon Cut in almandine under the sunny-day lighting.

What helps: the DG-Elongated Hexagon reads 88 for fire in almandine, the best of the cuts we score there.

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

Our verdict on the Hexagon Cut in almandine

Against the T73 in almandine and the same cut in diamond, no figure of the Hexagon Cut is ahead by our thresholds. The catch: it returns less light than the T73, has fewer facets to sparkle with, leaks more light than the T73 and shows less fire than in diamond.

If that catch matters more to you, the DG-M5 reads 99 for brilliance in almandine, the best of the cuts we score there.

Every figure on this page is from our light census, traced at one refractive index: a simulation of the geometry, not a grading report. The 3D files and cutting files below are the same Hexagon Cut model we traced.

Hexagon Cut Almandine: questions

Is the Hexagon a good cut for almandine?

In our census the Hexagon Cut returns 66 of 100 for brilliance and 68 for fire in almandine, against 95 and 54 for the T73 in the same stone. Against that round and against the same cut in diamond it has 0 pros and 4 cons by our thresholds; the summary above names them.

What pavilion angle does almandine need?

At least 36.3° for a round design: almandine's critical angle is 34.8°, from the low end of its refractive index range, and head-on light has to reflect off both sides of the pavilion and leave through the table. The Hexagon Cut's pavilion mains sit at 29.3°.

How much does a Hexagon weigh in almandine?

At 6.5 mm across, 1.51 ct in almandine, against 1.29 ct for the same cut in diamond (+17%): almandine's specific gravity is 4.125, diamond's 3.52.

Can I see the Hexagon in almandine in 3D?

Yes: the 3D Gemstone Simulator renders it live, with almandine's own refractive index and dispersion. Almandine is traced by the same light census as the other gemstones, with its refractive index and fire spread derived from published values, so its scores are on the same scale; the pictures here are our Light Return tracer, and the Cut Performance Wheel sets it against any other cut and stone.

Get the Hexagon Cut files

6 formatsMillimetersWatertight

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 modeling and rendering
  • FBXBlender, 3ds Max, Maya, Cinema 4D, Unity, Unreal
  • GLBWeb, AR and quick previews
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

Not sure the files open in your software? Get the cube free: the same six formats, for your email address, used only to send them (privacy).

Questions before you buy? Email us.

More gemstones and cuts

Almandine: optical properties and the top ten cuts · The Hexagon Cut: specifications, model and files

Other cuts in almandine

The Hexagon Cut in other gemstones