Asscher Cut Topaz: holds its light better in topaz than in diamond
Brilliance 65 · Fire 54 · Scintillation 72 · in our census, where the T73 scores 86 · 35 · 80 in topaz
How the Asscher Cut handles light in topaz, measured: brilliance 65, fire 54 and 33% leakage, set against the T73 in the same stone and against the same cut in diamond.
Light Return map of the Asscher Cut in topaz, face-up, from our own tracer at refractive index 1.606. Red, green and blue return light to the eye; gray leaks.
Asscher Cut Topaz
Topaz has a refractive index of 1.606 to 1.644 and a dispersion of 0.014. Its critical angle, from the low end of that range, is 38.5°, so a round design needs a pavilion of at least 38.5° for head-on light to reflect off both sides of the pavilion and leave through the table. We trace it with one index, 1.625, the midpoint of the published range, and a fire spread of 0.012, 0.86 of the published dispersion. Every picture here is our Light Return tracer at 1.606, and every figure is from the same light census that scores the other gemstones; the 3D Gemstone Simulator shows the Asscher Cut in topaz live.
The Asscher Cut has 58 facets and a total depth of 60.4% of its width; its pavilion mains sit at 27.6°. In topaz, the census returns 65 of 100 for brilliance and 54 for fire, against 86 and 35 for the T73, our benchmark, in the same stone; the same Asscher Cut in diamond reads 69 and 80.
Is topaz good in an Asscher? Pros and cons, measured
Compared with the T73 Round Brilliant in topaz and with the Asscher 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 Asscher Cut in topaz (white) against the T73 Round Brilliant in topaz (dashed): solid white where
it reaches further, hatched where it falls short. Each pro and con is explained, with pictures, below.
Against the T73 Round Brilliant in topaz: ahead on 3, level on 1, behind on 4.
Global70, the comparison 75, difference −5
Brilliance65, the comparison 86, difference −21
Fire54, the comparison 35, difference +19
Scintillation72, the comparison 80, difference −8
Spread107, the comparison 100, difference +7
Symmetry100, the comparison 100, difference 0
Shape-norm86, the comparison 92, difference −6
Tilt83, the comparison 74, difference +9
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 Asscher Cut gains in topaz
Holds its light better in topaz than in diamond
Tilt 83 against 79 for the Asscher Cut in diamond: 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 Asscher Cut keeps 83 against 79 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.
Asscher Cut in topaz · Tilt 83
0° · 30% leak
10° · 32% leak
20° · 39% leak
30° · 39% leak
Asscher Cut in diamond · Tilt 79
0° · 16% leak
10° · 19% leak
20° · 26% leak
30° · 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.
Fire 54 against 80 for the Asscher Cut in diamond: 26 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 (0.012 in topaz) and counts a ray as fire when the two directions differ by more than 0.6°. The Asscher Cut reads 54 against 80 for the same cut in diamond. The figure is the census's; the 3D Gemstone Simulator renders topaz'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 Asscher Cut in topaz under the sunny-day lighting.
What helps:the Oval Cut reads 68 for fire in topaz, the best of the cuts we score there.
Leakage 33 against 11 for the Asscher Cut in diamond: 22 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 Asscher Cut leaks 33% in topaz against 11% for the same cut in diamond. Grey in the maps below is leaking light; the share under each picture is that picture's own.
Asscher Cut in topaz · Leakage 33
0° · 30% leak
10° · 32% leak
20° · 39% leak
30° · 39% leak
Asscher Cut in diamond · Leakage 11
0° · 16% leak
10° · 19% leak
20° · 26% leak
30° · 26% 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 4% for leakage in topaz, the best of the cuts we score there.
Brilliance 65 against 86 for the T73 Round Brilliant in topaz: 21 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 topaz, whose critical angle is 38.5°, the Asscher Cut returns 65 of 100 and the T73 86. The Asscher Cut's pavilion mains sit at 27.6°, the T73's at 40.8°. The maps below show where each stone's light returns from and where it leaks.
Asscher Cut in topaz · Brilliance 65
T73 Round Brilliant in topaz · Brilliance 86
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 96 for brilliance in topaz, the best of the cuts we score there.
Scintillation 72 against 80 for the T73 Round Brilliant in topaz: 8 points lower
Scintillation follows the number of facets the stone shows: 100 × (1 − e^(−facets / 45)). The Asscher Cut has 58 facets and the T73 73, so 72 against 80. It depends on the geometry alone, so it is the same in every stone.
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 topaz, the best of the cuts we score there.
Pick the Asscher Cut in topaz for this: it holds its light better than in diamond when tilted. The catch: it shows less fire than in diamond, leaks more than in diamond, returns less light than the T73 and has fewer facets to sparkle with.
If that catch matters more to you, the Oval Cut reads 68 for fire in topaz, 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 Asscher Cut model we traced.
Asscher Cut Topaz: questions
Is the Asscher a good cut for topaz?
In our census the Asscher Cut returns 65 of 100 for brilliance and 54 for fire in topaz, against 86 and 35 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 topaz need?
At least 38.5° for a round design: topaz's critical angle is 38.5°, 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 Asscher Cut's pavilion mains sit at 27.6°.
How much does a Asscher weigh in topaz?
At 6.5 mm across, 1.35 ct in topaz, against 1.34 ct for the same cut in diamond, the same weight to the per cent: topaz's specific gravity is 3.535, diamond's 3.52.
Can I see the Asscher in topaz in 3D?
Yes: the 3D Gemstone Simulator renders it live, with topaz's own refractive index and dispersion. Topaz 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 Asscher Cut files
6 formatsMillimetersWatertight
Asscher Cut 3D files
The Asscher Cut as exact geometry: 58 planar facets, real-world scale, ready for CAD,
rendering, printing and casting.
Save with a bundle: the Asscher Cut 3D files are also in Jewelry Essentials 3D, 10 cuts for €29.99 until 1 December, then €39.99 (€99.90 as single files). Buy the bundle.
Save with a bundle: the Asscher Cut cutting files are also in Faceter's Classics, 10 cuts for €22.49 until 1 December, then €29.99 (€69.90 as single files). Buy the bundle.
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).
