DG-Octagonal Kite YAG: what our light census measures
Brilliance 79 · Fire 50 · Scintillation 60 · in our census, where the T73 scores 96 · 54 · 80 in YAG
How the DG-Octagonal Kite handles light in YAG, measured: brilliance 79, fire 50 and 21% leakage, set against the T73 in the same stone and against the same cut in diamond.
Light Return map of the DG-Octagonal Kite in YAG, face-up, from our own tracer at refractive index 1.833. Red, green and blue return light to the eye; gray leaks.
DG-Octagonal Kite YAG
YAG has a refractive index of 1.833 and a dispersion of 0.028. Its critical angle, from the low end of that range, is 33.1°, so a round design needs a pavilion of at least 36.7° for head-on light to reflect off both sides of the pavilion and leave through the table. We trace it with one index, 1.833, the midpoint of the published range, and a fire spread of 0.024, 0.86 of the published dispersion. Every picture here is our Light Return tracer at 1.833, and every figure is from the same light census that scores the other gemstones; the 3D Gemstone Simulator shows the DG-Octagonal Kite in YAG live.
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 YAG, the census returns 79 of 100 for brilliance and 50 for fire, against 96 and 54 for the T73, our benchmark, in the same stone; the same DG-Octagonal Kite in diamond reads 88 and 82.
Is YAG good in a DG-Octagonal Kite? Pros and cons, measured
Compared with the T73 Round Brilliant in YAG 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 YAG (white) against the T73 Round Brilliant in YAG (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 yag: ahead on 1, level on 1, behind on 6.
Global76, the comparison 83, difference −7
Brilliance79, the comparison 96, difference −17
Fire50, the comparison 54, difference −4
Scintillation60, the comparison 80, difference −20
Spread96, the comparison 100, difference −4
Symmetry100, the comparison 100, difference 0
Shape-norm91, the comparison 103, difference −12
Tilt94, the comparison 78, difference +16
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 YAG
Against the T73 in YAG and the same cut in diamond, no figure of the DG-Octagonal Kite is ahead by the thresholds above. Its figures are in the wheel and the FAQ; YAG ranks every cut we score in YAG.
What the DG-Octagonal Kite gives up in YAG
Less fire in YAG than in diamond
Fire 50 against 82 for the DG-Octagonal Kite in diamond: 32 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 (0.024 in YAG) and counts a ray as fire when the two directions differ by more than 0.6°. The DG-Octagonal Kite reads 50 against 82 for the same cut in diamond. The figure is the census's; the 3D Gemstone Simulator renders YAG'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 YAG under the sunny-day lighting.
What helps:the DG-Elongated Hexagon reads 93 for fire in YAG, the best of the cuts we score there.
1.61 ct at 6.5 mm, against 1.25 ct for the same cut in diamond (+29%)
Weight follows specific gravity: 4.55 for YAG against 3.52 for diamond, so the same model at the same size weighs 1.61 ct here and 1.25 ct in diamond, 6.5 mm across. Nothing about the light changes with it.
A DG-Octagonal Kite 6.5 mm across, weighed from the model's measured volume and each stone's specific gravity.
Scintillation 60 against 80 for the T73 Round Brilliant in YAG: 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.
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 YAG, the best of the cuts we score there.
Brilliance 79 against 96 for the T73 Round Brilliant in YAG: 17 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 YAG, whose critical angle is 33.1°, the DG-Octagonal Kite returns 79 of 100 and the T73 96. 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 YAG · Brilliance 79
T73 Round Brilliant in YAG · Brilliance 96
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 YAG, the best of the cuts we score there.
Against the T73 in YAG and the same cut in diamond, no figure of the DG-Octagonal Kite is ahead by our thresholds. The catch: it shows less fire than in diamond, weighs more than in diamond, has fewer facets to sparkle with and returns less light than the T73.
If that catch matters more to you, the DG-Elongated Hexagon reads 93 for fire in YAG, 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 YAG: questions
Is the DG-Octagonal Kite a good cut for YAG?
In our census the DG-Octagonal Kite returns 79 of 100 for brilliance and 50 for fire in YAG, against 96 and 54 for the T73 in the same stone. Against that round and against the same cut in diamond it has 0 pros and 4 cons by our thresholds; the summary above names them.
What pavilion angle does YAG need?
At least 36.7° for a round design: YAG's critical angle is 33.1°, 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 YAG?
At 6.5 mm across, 1.61 ct in YAG, against 1.25 ct for the same cut in diamond (+29%): YAG's specific gravity is 4.55, diamond's 3.52.
Can I see the DG-Octagonal Kite in YAG in 3D?
Yes: the 3D Gemstone Simulator renders it live, with YAG's own refractive index and dispersion. YAG 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
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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.
