DG-Octagonal Kite Strontium titanate: more fire in strontium titanate than in diamond

Brilliance 88 · Fire 93 · Scintillation 60 · in our census, where the T73 scores 93 · 98 · 80 in strontium titanate

How the DG-Octagonal Kite handles light in strontium titanate, measured: brilliance 88, fire 93 and 7% leakage, set against the T73 in the same stone and against the same cut in diamond.

The DG-Octagonal Kite in strontium titanate, face-up Light Return map from our tracer at refractive index 2.409: red, green and blue show where the light returns from, gray shows where it leaks
Light Return map of the DG-Octagonal Kite in strontium titanate, face-up, from our own tracer at refractive index 2.409. Red, green and blue return light to the eye; gray leaks.

DG-Octagonal Kite Strontium titanate

Strontium titanate has a refractive index of 2.409 and a dispersion of 0.190. Its critical angle, from the low end of that range, is 24.5°, so a round design needs a pavilion of at least 38.9° for head-on light to reflect off both sides of the pavilion and leave through the table. We trace it with one index, 2.409, the midpoint of the published range, and a fire spread of 0.163, 0.86 of the published dispersion. Every picture here is our Light Return tracer at 2.409, and every figure is from the same light census that scores the other gemstones; the 3D Gemstone Simulator shows the DG-Octagonal Kite in strontium titanate live. Strontium titanate has nearly diamond's refractive index (2.409 against 2.417) with about four times its dispersion (0.190 against 0.044): light takes much the same paths as in diamond, and far more of it splits into color.

The DG-Octagonal Kite has 41 facets, a table of 55.0% of its width and a total depth of 70.0% of its width; its pavilion mains sit at 43.0°. In strontium titanate, the census returns 88 of 100 for brilliance and 93 for fire, against 93 and 98 for the T73, our benchmark, in the same stone; the same DG-Octagonal Kite in diamond reads 88 and 82.

Is strontium titanate good in a DG-Octagonal Kite? Pros and cons, measured

Compared with the T73 Round Brilliant in strontium titanate 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 strontium titanate (white) against the T73 Round Brilliant in strontium titanate (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 strontium titanate, against the T73 Round Brilliant in strontium titanate as an outline. Solid white marks where it reaches further, hatching where it falls short. The scores are listed below.50100Global−6Brilliance−5Fire−5Scintillation−20Spread−4Symmetry0Shape-norm+2Tilt−4

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

  • Global88, the comparison 94, difference −6
  • Brilliance88, the comparison 93, difference −5
  • Fire93, the comparison 98, difference −5
  • Scintillation60, the comparison 80, difference −20
  • Spread96, the comparison 100, difference −4
  • Symmetry100, the comparison 100, difference 0
  • Shape-norm102, the comparison 100, difference +2
  • Tilt88, the comparison 92, 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-Octagonal Kite gains in strontium titanate

More fire in strontium titanate than in diamond

Fire 93 against 82 for the DG-Octagonal Kite in diamond: 11 points higher

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 (0.163 in strontium titanate) and counts a ray as fire when the two directions differ by more than 0.6°. The DG-Octagonal Kite reads 93 against 82 for the same cut in diamond. The figure is the census's; the 3D Gemstone Simulator renders strontium titanate'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-Octagonal Kite in strontium titanate under the sunny-day lighting.

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

What the DG-Octagonal Kite gives up in strontium titanate

Heavier than the same cut in diamond

1.82 ct at 6.5 mm, against 1.25 ct for the same cut in diamond (+46%)

Weight follows specific gravity: 5.13 for strontium titanate against 3.52 for diamond, so the same model at the same size weighs 1.82 ct here and 1.25 ct in diamond, 6.5 mm across. Nothing about the light changes with it.

Strontium titanate1.82 ctDiamond1.25 ct
A DG-Octagonal Kite 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-Octagonal Kite page

Fewer facets, less sparkle

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

Scintillation follows the number of facets the stone shows: 100 × (1 − e^(−facets / 45)). The DG-Octagonal Kite has 41 facets and the T73 73, so 60 against 80. It depends on the geometry alone, so it is the same in every stone.

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. 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 strontium titanate, the best of the cuts we score there.

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

Faces up smaller for its weight

Face-up size 94 against 100 for the T73 Round Brilliant in strontium titanate (T73 = 100): 6% less face-up area for the same weight

Face-up size is the outline's area per carat, measured from each model (T73 = 100): 94 for the DG-Octagonal Kite against 100 for the T73. The same volume spread over a longer or shallower outline shows more face for the weight; it is the same in every stone, because specific gravity scales every cut alike.

DG-Octagonal Kite · 5.33 mm at 1.00 ct · Face-up size 94

T73 Round Brilliant · 5.72 mm at 1.00 ct · Face-up size 100

Both stones weigh 1.00 ct in strontium titanate and are drawn to the same scale in millimeters, 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: the Marquise Cut reads 121 for face-up size in strontium titanate, the best of the cuts we score there.

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

Returns less light than the T73 in strontium titanate

Brilliance 88 against 93 for the T73 Round Brilliant in strontium titanate: 5 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 strontium titanate, whose critical angle is 24.5°, the DG-Octagonal Kite returns 88 of 100 and the T73 93. The DG-Octagonal Kite's pavilion mains sit at 43.0°, the T73's at 40.8°. The maps below show where each stone's light returns from and where it leaks.

Dg-octagonal kite in strontium titanate face-up Light Return map: red, green and blue show where the light returns from, gray shows where it leaks (Brilliance 88)

DG-Octagonal Kite in strontium titanate · Brilliance 88

T73 round brilliant in strontium titanate face-up Light Return map: red, green and blue show where the light returns from, gray shows where it leaks (Brilliance 93)

T73 Round Brilliant in strontium titanate · Brilliance 93

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 strontium titanate, the best of the cuts we score there.

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

Our verdict on the DG-Octagonal Kite in strontium titanate

Pick the DG-Octagonal Kite in strontium titanate for this: it shows more fire than in diamond. The catch: it weighs more than in diamond, has fewer facets to sparkle with, faces up smaller for its weight and returns less light than the T73.

If that catch matters more to you, the DG-Miliano reads 98 for scintillation in strontium titanate, 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-Octagonal Kite model we traced.

DG-Octagonal Kite Strontium titanate: questions

Is the DG-Octagonal Kite a good cut for strontium titanate?

In our census the DG-Octagonal Kite returns 88 of 100 for brilliance and 93 for fire in strontium titanate, against 93 and 98 for the T73 in the same stone. Against that round and against the same cut in diamond it has 1 pro and 4 cons by our thresholds; the summary above names them.

What pavilion angle does strontium titanate need?

At least 38.9° for a round design: strontium titanate's critical angle is 24.5°, 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-Octagonal Kite's pavilion mains sit at 43.0°.

How much does a DG-Octagonal Kite weigh in strontium titanate?

At 6.5 mm across, 1.82 ct in strontium titanate, against 1.25 ct for the same cut in diamond (+46%): strontium titanate's specific gravity is 5.13, diamond's 3.52.

Can I see the DG-Octagonal Kite in strontium titanate in 3D?

Yes: the 3D Gemstone Simulator renders it live, with strontium titanate's own refractive index and dispersion. Strontium titanate 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-Octagonal Kite Cut files

6 formatsMillimetersWatertight

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

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

Strontium titanate: optical properties and the top ten cuts · The DG-Octagonal Kite: specifications, model and files

Other cuts in strontium titanate

The DG-Octagonal Kite in other gemstones