DG-Octagonal Kite Sapphire: steady light at a tilt, with less light and fire than a round

Brilliance 74 · Fire 34 · Scintillation 60 · in our census, where the T73 scores 94 · 37 · 80 in sapphire

Eight kites around a large table: in sapphire this house cut trails the round on light and the diamond version on fire, and holds steady when tipped.

See it in the simulatorGet the files
The DG-Octagonal Kite in sapphire, rendered at an angle in our 3D Gemstone Simulator under studio light
Rendered in our 3D Gemstone Simulator from the DG-Octagonal Kite model, 1.00 ct, studio light.

DG-Octagonal Kite Sapphire

DG-Octagonal Kite is an eight-fold cut with a large octagonal table. Kites run from the girdle corners to the table, over triangles on the girdle flats, and the pavilion repeats the pattern in long kites that close to a point. The model carries 41 facets: a 55.0% table, a 32.0° crown, a 43.0° pavilion and 70.0% total depth.

It was drawn for emerald. In sapphire its 43.0° pavilion is well above the 36.4° guide minimum, and still about a quarter of the light leaks.

Does DG-Octagonal Kite suit a sapphire? Pros and cons

Pros

None by our margins. It holds its light when tipped, from less light than a round.

Cons

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

Performance wheel: DG-Octagonal Kite in sapphire, against the T73 Round Brilliant in sapphire as an outline. Solid white marks where it reaches further, hatching where it falls short. The scores are listed below.50100Global−8Brilliance−20Fire−3Scintillation−20Spread−4Symmetry0Shape-norm−17Tilt+20

Against the T73 Round Brilliant in sapphire: ahead on 1, level on 1, behind on 6.

  • Global71, the comparison 79, difference −8
  • Brilliance74, the comparison 94, difference −20
  • Fire34, the comparison 37, difference −3
  • Scintillation60, the comparison 80, difference −20
  • Spread96, the comparison 100, difference −4
  • Symmetry100, the comparison 100, difference 0
  • Shape-norm85, the comparison 102, difference −17
  • Tilt95, the comparison 75, difference +20
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 a sapphire gains as DG-Octagonal Kite

No score counts as a pro against the T73 or the diamond version. Its Tilt is high, 95, above both the T73's 75 and the diamond's 89; but a tilt score counts as a pro only when the stone's brilliance is within five points of the baseline's, and at 74 against 94 and 88 it is not. What it offers is a bold, symmetrical outline for a coloured centre stone.

Where DG-Octagonal Kite falls short in sapphire

Far less fire than the diamond version

Fire 34 against 82 for the DG-Octagonal Kite in diamond: 48 points lower

34 in sapphire, 82 in diamond, and a little under the T73 in sapphire, 37. The design is the same in both stones, so the gap to diamond comes from the stone.

Dg-octagonal kite in sapphire face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 34)

DG-Octagonal Kite in sapphire · Fire 34

Dg-octagonal kite in diamond face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 82)

DG-Octagonal Kite in diamond · Fire 82

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.

What helps: For fire with near-round light in sapphire, the Trilliant Cut Sapphire reaches 52 and DG-Anteros Sapphire 43.

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

Over five times the T73's leakage

Leakage 26 against 5 for the T73 Round Brilliant in sapphire: 21 points higher

26% of the light in our census leaves through the pavilion; the T73 loses 5%, and the same design in diamond 7%. In this design, sapphire's lower refractive index lets far more out.

DG-Octagonal Kite in sapphire · Leakage 26

Dg-octagonal kite in sapphire tilted 0 degrees: Light Return map, 28% of the face leaking0° · 28% leak
Dg-octagonal kite in sapphire tilted 10 degrees: Light Return map, 22% of the face leaking10° · 22% leak
Dg-octagonal kite in sapphire tilted 20 degrees: Light Return map, 30% of the face leaking20° · 30% leak
Dg-octagonal kite in sapphire tilted 30 degrees: Light Return map, 38% of the face leaking30° · 38% leak

T73 Round Brilliant in sapphire · Leakage 5

T73 round brilliant in sapphire tilted 0 degrees: Light Return map, 1% of the face leaking0° · 1% leak
T73 round brilliant in sapphire tilted 10 degrees: Light Return map, 10% of the face leaking10° · 10% leak
T73 round brilliant in sapphire tilted 20 degrees: Light Return map, 29% of the face leaking20° · 29% leak
T73 round brilliant in sapphire 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; grey is light leaving through the pavilion. The share under each frame is that picture's own.

What helps: The pavilion, 43.0°, is past sapphire's 36.4° guide minimum; we have not measured a steeper version. The Octagon Cut Sapphire leaks 20%.

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

About a fifth less light than the T73

Brilliance 74 against 94 for the T73 Round Brilliant in sapphire: 20 points lower

Brilliance 74 against 94. In diamond the same kites return 88.

Dg-octagonal kite in sapphire face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 74)

DG-Octagonal Kite in sapphire · Brilliance 74

T73 round brilliant in sapphire face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 94)

T73 Round Brilliant in sapphire · Brilliance 94

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: On an eight-sided outline, the Octagon Cut Sapphire returns more, 78; DG-M5 Sapphire returns the most, 100.

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

Fewer flashes than a round

Scintillation 60 against 80 for the T73 Round Brilliant in sapphire: 20 points lower

Scintillation 60 against 80: 41 facets around a large table, against the T73's 73.

DG-Octagonal Kite · 41 facets · Scintillation 60

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 plain Octagon Cut Sapphire sparkles a little more, 66.

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

Who a DG-Octagonal Kite sapphire suits

DG-Octagonal Kite suits a coloured centre stone where a bold, symmetrical pattern matters and the ring will often be seen at an angle. In sapphire its light is fair and its fire low.

In sapphire the plain Octagon Cut Sapphire does better on light, leakage and sparkle; DG-Octagonal Kite is the one to pick for its pattern and its hold at a tilt. For the most light, DG-M5 Sapphire.

DG-Octagonal Kite Sapphire: questions

Is DG-Octagonal Kite good for sapphire?

It is steady rather than bright: Tilt 95, Brilliance 74 against 94 for the T73, and Fire 34.

DG-Octagonal Kite or octagon cut for a sapphire?

The octagon returns more light (78 against 74) and leaks less (20% against 26%). DG-Octagonal Kite holds its light better at a tilt, 95 against 87.

What does a 6.5 mm DG-Octagonal Kite sapphire weigh?

1.42 ct in sapphire; the diamond version would be 1.25 ct.

Get the DG-Octagonal Kite Cut files

6 formatsMillimetresWatertight

DG-Octagonal Kite Cut 3D files

The DG-Octagonal Kite Cut as exact geometry: 41 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

DG-Octagonal Kite Cut cutting files

The DG-Octagonal Kite Cut as a faceting design: 33 + 8 girdles = 41 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
€9.99 · Personal useBuy the cutting files

Questions before you buy? Email us.

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