DG-Miliano Zircon: more facets, more sparkle

Brilliance 96 · Fire 73 · Scintillation 98 · in our census, where the T73 scores 98 · 69 · 80 in zircon

How the DG-Miliano handles light in zircon, measured: brilliance 96, fire 73 and 4% leakage, set against the T73 in the same stone and against the same cut in diamond.

The DG-Miliano in zircon, face-up Light Return map from our tracer at refractive index 1.925: red, green and blue show where the light returns from, gray shows where it leaks
Light Return map of the DG-Miliano in zircon, face-up, from our own tracer at refractive index 1.925. Red, green and blue return light to the eye; gray leaks.

DG-Miliano Zircon

Zircon has a refractive index of 1.925 to 1.984 and a dispersion of 0.039. Its critical angle, from the low end of that range, is 31.3°, so a round design needs a pavilion of at least 37.2° for head-on light to reflect off both sides of the pavilion and leave through the table. We trace it with one index, 1.955, the midpoint of the published range, and a fire spread of 0.034, 0.86 of the published dispersion. Every picture here is our Light Return tracer at 1.925, and every figure is from the same light census that scores the other gemstones; the 3D Gemstone Simulator shows the DG-Miliano in zircon live. Zircon is strongly doubly refractive (birefringence up to 0.059), so its back facets can look doubled. Our census traces one index (1.955), so the doubling is not in these figures.

The DG-Miliano has 177 facets and a total depth of 60.3% of its width; its pavilion mains sit at 38.3°. In zircon, the census returns 96 of 100 for brilliance and 73 for fire, against 98 and 69 for the T73, our benchmark, in the same stone; the same DG-Miliano in diamond reads 95 and 82.

Is zircon good in a DG-Miliano? Pros and cons, measured

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

Performance wheel: DG-Miliano in zircon, against the T73 Round Brilliant in zircon as an outline. Solid white marks where it reaches further, hatching where it falls short. The scores are listed below.50100Global+2Brilliance−2Fire+4Scintillation+18Spread+1Symmetry0Shape-norm−2Tilt+4

Against the T73 Round Brilliant in zircon: ahead on 5, level on 1, behind on 2.

  • Global90, the comparison 88, difference +2
  • Brilliance96, the comparison 98, difference −2
  • Fire73, the comparison 69, difference +4
  • Scintillation98, the comparison 80, difference +18
  • Spread101, the comparison 100, difference +1
  • Symmetry100, the comparison 100, difference 0
  • Shape-norm103, the comparison 105, difference −2
  • Tilt86, the comparison 82, difference +4
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 DG-Miliano gains in zircon

More facets, more sparkle

Scintillation 98 against 80 for the T73 Round Brilliant in zircon: 18 points higher

Scintillation follows the number of facets the stone shows: 100 × (1 − e^(−facets / 45)). The DG-Miliano has 177 facets and the T73 73, so 98 against 80. It depends on the geometry alone, so it is the same in every stone.

DG-Miliano · 177 facets · Scintillation 98

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.

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

Keeps its light when tilted

Tilt 86 against 82 for the T73 Round Brilliant in zircon: 4 points higher

Tilt is how much of its face-up brilliance a stone keeps when the census tilts it 20° about its long axis, with 2,200 rays. The DG-Miliano keeps 86 against 82 for the T73. The tilt strips below show the maps at 0°, 10°, 20° and 30°, with each picture's own leak share under it.

DG-Miliano in zircon · Tilt 86

Dg-miliano in zircon tilted 0 degrees: Light Return map, 3% of the face leaking0° · 3% leak
Dg-miliano in zircon tilted 10 degrees: Light Return map, 6% of the face leaking10° · 6% leak
Dg-miliano in zircon tilted 20 degrees: Light Return map, 11% of the face leaking20° · 11% leak
Dg-miliano in zircon tilted 30 degrees: Light Return map, 27% of the face leaking30° · 27% leak

T73 Round Brilliant in zircon · Tilt 82

T73 round brilliant in zircon tilted 0 degrees: Light Return map, 1% of the face leaking0° · 1% leak
T73 round brilliant in zircon tilted 10 degrees: Light Return map, 6% of the face leaking10° · 6% leak
T73 round brilliant in zircon tilted 20 degrees: Light Return map, 15% of the face leaking20° · 15% leak
T73 round brilliant in zircon tilted 30 degrees: Light Return map, 26% of the face leaking30° · 26% leak
Tilt is how much of its own face-up light a stone keeps when tilted. 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.

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

What the DG-Miliano gives up in zircon

Heavier than the same cut in diamond

1.37 ct at 6.5 mm, against 1.03 ct for the same cut in diamond (+33%)

Weight follows specific gravity: 4.665 for zircon against 3.52 for diamond, so the same model at the same size weighs 1.37 ct here and 1.03 ct in diamond, 6.5 mm across. Nothing about the light changes with it.

Zircon1.37 ctDiamond1.03 ct
A DG-Miliano 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 DG-Miliano page

Less fire in zircon than in diamond

Fire 73 against 82 for the DG-Miliano in diamond: 9 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 (0.034 in zircon) and counts a ray as fire when the two directions differ by more than 0.6°. The DG-Miliano reads 73 against 82 for the same cut in diamond. The figure is the census's; the 3D Gemstone Simulator renders zircon'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 DG-Miliano in zircon under the sunny-day lighting.

What helps: the DG-Elongated Hexagon reads 93 for fire in zircon, the best of the cuts we score there.

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

Our verdict on the DG-Miliano in zircon

Pick the DG-Miliano in zircon for this: it has more facets to sparkle with and keeps its light when tilted. The catch: it weighs more than in diamond and shows less fire than in diamond.

If that catch matters more to you, the DG-Elongated Hexagon reads 93 for fire in zircon, 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 DG-Miliano model we traced.

DG-Miliano Zircon: questions

Is the DG-Miliano a good cut for zircon?

In our census the DG-Miliano returns 96 of 100 for brilliance and 73 for fire in zircon, against 98 and 69 for the T73 in the same stone. Against that round and against the same cut in diamond it has 2 pros and 2 cons by our thresholds; the summary above names them.

What pavilion angle does zircon need?

At least 37.2° for a round design: zircon's critical angle is 31.3°, 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 DG-Miliano's pavilion mains sit at 38.3°.

How much does a DG-Miliano weigh in zircon?

At 6.5 mm across, 1.37 ct in zircon, against 1.03 ct for the same cut in diamond (+33%): zircon's specific gravity is 4.665, diamond's 3.52.

Can I see the DG-Miliano in zircon in 3D?

Yes: the 3D Gemstone Simulator renders it live, with zircon's own refractive index and dispersion. Zircon 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 DG-Miliano Cut files

6 formatsMillimetersWatertight

DG-Miliano Cut 3D files

The DG-Miliano Cut as exact geometry: 177 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

DG-Miliano Cut cutting files

The DG-Miliano Cut as a faceting design: 81 + 96 girdles = 177 facets, 96 index, 8-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

Zircon: optical properties and the top ten cuts · The DG-Miliano: specifications, model and files

Other cuts in zircon

The DG-Miliano in other gemstones