Triangle Cut Synthetic rutile: more fire in synthetic rutile than in diamond

Brilliance 51 · Fire 95 · Scintillation 34 · in our census, where the T73 scores 81 · 94 · 80 in synthetic rutile

How the Triangle Cut handles light in synthetic rutile, measured: brilliance 51, fire 95 and 19% leakage, set against the T73 in the same stone and against the same cut in diamond.

The Triangle Cut in synthetic rutile, face-up Light Return map from our tracer at refractive index 2.616: red, green and blue show where the light returns from, gray shows where it leaks
Light Return map of the Triangle Cut in synthetic rutile, face-up, from our own tracer at refractive index 2.616. Red, green and blue return light to the eye; gray leaks.

Triangle Cut Synthetic rutile

Synthetic rutile has a refractive index of 2.616 to 2.903 and a dispersion of 0.330. Its critical angle, from the low end of that range, is 22.5°, so a round design needs a pavilion of at least 39.4° for head-on light to reflect off both sides of the pavilion and leave through the table. We trace it with one index, 2.760, the midpoint of the published range, and a fire spread of 0.284, 0.86 of the published dispersion. Every picture here is our Light Return tracer at 2.616, and every figure is from the same light census that scores the other gemstones; the 3D Gemstone Simulator shows the Triangle Cut in synthetic rutile live. Synthetic rutile is strongly doubly refractive (birefringence 0.287): its two rays have critical angles of 22.5° and 20.1°. Our census traces one index, so every figure for it is a rough approximation.

The Triangle Cut has 19 facets, a table of 60.0% of its width and a total depth of 55.4% of its width; its pavilion mains sit at 41.8°. In synthetic rutile, the census returns 51 of 100 for brilliance and 95 for fire, against 81 and 94 for the T73, our benchmark, in the same stone; the same Triangle Cut in diamond reads 53 and 86.

Is synthetic rutile good in a Triangle? Pros and cons, measured

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

Performance wheel: Triangle Cut in synthetic rutile, against the T73 Round Brilliant in synthetic rutile as an outline. Solid white marks where it reaches further, hatching where it falls short. The scores are listed below.50100Global−14Brilliance−30Fire+1Scintillation−46Spread+4Symmetry0Shape-norm−19Tilt+6

Against the T73 Round Brilliant in synthetic rutile: ahead on 3, level on 1, behind on 4.

  • Global74, the comparison 88, difference −14
  • Brilliance51, the comparison 81, difference −30
  • Fire95, the comparison 94, difference +1
  • Scintillation34, the comparison 80, difference −46
  • Spread104, the comparison 100, difference +4
  • Symmetry100, the comparison 100, difference 0
  • Shape-norm68, the comparison 87, difference −19
  • Tilt100, the comparison 94, difference +6
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 Triangle Cut gains in synthetic rutile

More fire in synthetic rutile than in diamond

Fire 95 against 86 for the Triangle Cut in diamond: 9 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 (0.284 in synthetic rutile) and counts a ray as fire when the two directions differ by more than 0.6°. The Triangle Cut reads 95 against 86 for the same cut in diamond. The figure is the census's; the 3D Gemstone Simulator renders synthetic rutile'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 Triangle Cut in synthetic rutile under the sunny-day lighting.

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

Holds its light better in synthetic rutile than in diamond

Tilt 100 against 94 for the Triangle Cut in diamond: 6 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 Triangle Cut keeps 100 against 94 for the same cut in diamond. The tilt strips below show the maps at 0°, 10°, 20° and 30°, with each picture's own leak share under it.

Triangle Cut in synthetic rutile · Tilt 100

Triangle cut in synthetic rutile tilted 0 degrees: Light Return map, 28% of the face leaking0° · 28% leak
Triangle cut in synthetic rutile tilted 10 degrees: Light Return map, 30% of the face leaking10° · 30% leak
Triangle cut in synthetic rutile tilted 20 degrees: Light Return map, 32% of the face leaking20° · 32% leak
Triangle cut in synthetic rutile tilted 30 degrees: Light Return map, 36% of the face leaking30° · 36% leak

Triangle Cut in diamond · Tilt 94

Triangle cut in diamond tilted 0 degrees: Light Return map, 25% of the face leaking0° · 25% leak
Triangle cut in diamond tilted 10 degrees: Light Return map, 29% of the face leaking10° · 29% leak
Triangle cut in diamond tilted 20 degrees: Light Return map, 34% of the face leaking20° · 34% leak
Triangle cut in diamond tilted 30 degrees: Light Return map, 34% of the face leaking30° · 34% 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 Triangle Cut gives up in synthetic rutile

Fewer facets, less sparkle

Scintillation 34 against 80 for the T73 Round Brilliant in synthetic rutile: 46 points lower

Scintillation follows the number of facets the stone shows: 100 × (1 − e^(−facets / 45)). The Triangle Cut has 19 facets and the T73 73, so 34 against 80. It depends on the geometry alone, so it is the same in every stone.

Triangle Cut · 19 facets · Scintillation 34

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 synthetic rutile, the best of the cuts we score there.

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

Returns less light than the T73 in synthetic rutile

Brilliance 51 against 81 for the T73 Round Brilliant in synthetic rutile: 30 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 synthetic rutile, whose critical angle is 22.5°, the Triangle Cut returns 51 of 100 and the T73 81. The Triangle Cut's pavilion mains sit at 41.8°, the T73's at 40.8°. The maps below show where each stone's light returns from and where it leaks.

Triangle cut in synthetic rutile face-up Light Return map: red, green and blue show where the light returns from, gray shows where it leaks (Brilliance 51)

Triangle Cut in synthetic rutile · Brilliance 51

T73 round brilliant in synthetic rutile face-up Light Return map: red, green and blue show where the light returns from, gray shows where it leaks (Brilliance 81)

T73 Round Brilliant in synthetic rutile · Brilliance 81

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 synthetic rutile, 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

0.96 ct at 6.5 mm, against 0.79 ct for the same cut in diamond (+21%)

Weight follows specific gravity: 4.26 for synthetic rutile against 3.52 for diamond, so the same model at the same size weighs 0.96 ct here and 0.79 ct in diamond, 6.5 mm across. Nothing about the light changes with it.

Synthetic rutile0.96 ctDiamond0.79 ct
A Triangle 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 Triangle Cut page

Faces up smaller for its weight

Face-up size 89 against 100 for the T73 Round Brilliant in synthetic rutile (T73 = 100): 11% less face-up area for the same weight

Face-up size is the outline's area per carat, measured from each model (T73 = 100): 89 for the Triangle Cut 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.

Triangle Cut · 7.62 x 6.60 mm at 1.00 ct · Face-up size 89

T73 Round Brilliant · 6.08 mm at 1.00 ct · Face-up size 100

Both stones weigh 1.00 ct in synthetic rutile 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 synthetic rutile, the best of the cuts we score there.

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

Our verdict on the Triangle Cut in synthetic rutile

Pick the Triangle Cut in synthetic rutile for this: it shows more fire than in diamond and holds its light better than in diamond when tilted. The catch: it has fewer facets to sparkle with, returns less light than the T73, weighs more than in diamond and faces up smaller for its weight.

If that catch matters more to you, the DG-Miliano reads 98 for scintillation in synthetic rutile, 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 Triangle Cut model we traced.

Triangle Cut Synthetic rutile: questions

Is the Triangle a good cut for synthetic rutile?

In our census the Triangle Cut returns 51 of 100 for brilliance and 95 for fire in synthetic rutile, against 81 and 94 for the T73 in the same stone. Against that round and against the same cut in diamond it has 2 pros and 4 cons by our thresholds; the summary above names them.

What pavilion angle does synthetic rutile need?

At least 39.4° for a round design: synthetic rutile's critical angle is 22.5°, 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 Triangle Cut's pavilion mains sit at 41.8°.

How much does a Triangle weigh in synthetic rutile?

At 6.5 mm across, 0.96 ct in synthetic rutile, against 0.79 ct for the same cut in diamond (+21%): synthetic rutile's specific gravity is 4.26, diamond's 3.52.

Can I see the Triangle in synthetic rutile in 3D?

Yes: the 3D Gemstone Simulator renders it live, with synthetic rutile's own refractive index and dispersion. Synthetic rutile 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 Triangle Cut files

6 formatsMillimetersWatertight

Triangle Cut 3D files

The Triangle Cut as exact geometry: 19 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

Triangle Cut cutting files

The Triangle Cut as a faceting design: 16 + 3 girdles = 19 facets, 96 index, 3-fold 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

Synthetic rutile: optical properties and the top ten cuts · The Triangle Cut: specifications, model and files

Other cuts in synthetic rutile

The Triangle Cut in other gemstones