Hexagon Cut YAG: what our light census measures

Brilliance 67 · Fire 68 · Scintillation 56 · in our census, where the T73 scores 96 · 54 · 80 in YAG

How the Hexagon Cut handles light in YAG, measured: brilliance 67, fire 68 and 23% leakage, set against the T73 in the same stone and against the same cut in diamond.

The Hexagon Cut in YAG, face-up Light Return map from our tracer at refractive index 1.833: red, green and blue show where the light returns from, gray shows where it leaks
Light Return map of the Hexagon Cut in YAG, face-up, from our own tracer at refractive index 1.833. Red, green and blue return light to the eye; gray leaks.

Hexagon Cut YAG

YAG has a refractive index of 1.833 and a dispersion of 0.028. Its critical angle, from the low end of that range, is 33.1°, so a round design needs a pavilion of at least 36.7° for head-on light to reflect off both sides of the pavilion and leave through the table. We trace it with one index, 1.833, the midpoint of the published range, and a fire spread of 0.024, 0.86 of the published dispersion. Every picture here is our Light Return tracer at 1.833, and every figure is from the same light census that scores the other gemstones; the 3D Gemstone Simulator shows the Hexagon Cut in YAG 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 YAG, the census returns 67 of 100 for brilliance and 68 for fire, against 96 and 54 for the T73, our benchmark, in the same stone; the same Hexagon Cut in diamond reads 58 and 85.

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

Compared with the T73 Round Brilliant in YAG 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 YAG (white) against the T73 Round Brilliant in YAG (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 yag, against the T73 Round Brilliant in yag 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 yag: ahead on 2, level on 2, behind on 4.

  • Global75, the comparison 83, difference −8
  • Brilliance67, the comparison 96, 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-norm88, the comparison 103, difference −15
  • Tilt97, the comparison 78, 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 YAG

Against the T73 in YAG 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; YAG ranks every cut we score in YAG.

What the Hexagon Cut gives up in YAG

Returns less light than the T73 in YAG

Brilliance 67 against 96 for the T73 Round Brilliant in YAG: 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 YAG, whose critical angle is 33.1°, the Hexagon Cut returns 67 of 100 and the T73 96. 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 yag face-up Light Return map: red, green and blue show where the light returns from, gray shows where it leaks (Brilliance 67)

Hexagon Cut in YAG · Brilliance 67

T73 round brilliant in yag face-up Light Return map: red, green and blue show where the light returns from, gray shows where it leaks (Brilliance 96)

T73 Round Brilliant in YAG · Brilliance 96

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 97 for brilliance in YAG, the best of the cuts we score there.

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

Heavier than the same cut in diamond

1.66 ct at 6.5 mm, against 1.29 ct for the same cut in diamond (+29%)

Weight follows specific gravity: 4.55 for YAG against 3.52 for diamond, so the same model at the same size weighs 1.66 ct here and 1.29 ct in diamond, 6.5 mm across. Nothing about the light changes with it.

YAG1.66 ctDiamond1.29 ct
A Hexagon Cut 6.5 mm across, weighed from the model's measured volume and each stone's specific gravity.

Try it yourself: Weights in every gemstone on the Hexagon Cut page

Fewer facets, less sparkle

Scintillation 56 against 80 for the T73 Round Brilliant in YAG: 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 YAG, 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 YAG

Leakage 23 against 4 for the T73 Round Brilliant in YAG: 19 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 YAG against 4% for the T73 in YAG. Grey in the maps below is leaking light; the share under each picture is that picture's own.

Hexagon Cut in YAG · Leakage 23

Hexagon cut in yag tilted 0 degrees: Light Return map, 21% of the face leaking0° · 21% leak
Hexagon cut in yag tilted 10 degrees: Light Return map, 23% of the face leaking10° · 23% leak
Hexagon cut in yag tilted 20 degrees: Light Return map, 24% of the face leaking20° · 24% leak
Hexagon cut in yag tilted 30 degrees: Light Return map, 28% of the face leaking30° · 28% leak

T73 Round Brilliant in YAG · Leakage 4

T73 round brilliant in yag tilted 0 degrees: Light Return map, 1% of the face leaking0° · 1% leak
T73 round brilliant in yag tilted 10 degrees: Light Return map, 6% of the face leaking10° · 6% leak
T73 round brilliant in yag tilted 20 degrees: Light Return map, 19% of the face leaking20° · 19% leak
T73 round brilliant in yag tilted 30 degrees: Light Return map, 29% of the face leaking30° · 29% 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 3% for leakage in YAG, the best of the cuts we score there.

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

Our verdict on the Hexagon Cut in YAG

Against the T73 in YAG 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, weighs more than in diamond, has fewer facets to sparkle with and leaks more light than the T73.

If that catch matters more to you, the DG-M5 reads 97 for brilliance in YAG, 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 YAG: questions

Is the Hexagon a good cut for YAG?

In our census the Hexagon Cut returns 67 of 100 for brilliance and 68 for fire in YAG, against 96 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 YAG need?

At least 36.7° for a round design: YAG's critical angle is 33.1°, 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 YAG?

At 6.5 mm across, 1.66 ct in YAG, against 1.29 ct for the same cut in diamond (+29%): YAG's specific gravity is 4.55, diamond's 3.52.

Can I see the Hexagon in YAG in 3D?

Yes: the 3D Gemstone Simulator renders it live, with YAG's own refractive index and dispersion. YAG 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

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

Other cuts in YAG

The Hexagon Cut in other gemstones