---
title: "Radiant Cut Tourmaline: Pros, Cons and Scores"
description: "Radiant Cut in tourmaline: brilliance 23, fire 78, leakage 73%, 3 pros and 3 cons against the T73, from our ray-traced light census."
url: https://digitalgemology.com/gemstones/tourmaline/radiant
image: https://digitalgemology.com/img/stone-cuts/radiant-tourmaline-og.jpg?v=9b7e422c
---

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# Radiant Cut Tourmaline: more fire than the T73 in tourmaline

**Buy (instant download, personal-use license):** [Radiant Cut 3D files, €9.99 · Personal use](https://digitalgemology.lemonsqueezy.com/checkout/buy/37db9344-72d1-4dac-89e9-88dc3539c639) · [Buy the bundle](https://digitalgemology.lemonsqueezy.com/checkout/buy/e5c79ed5-97ce-4c62-8dbe-3a172c6245ba?checkout%5Bdiscount_code%5D=BUNDLE25) · [Get the cube free](https://digitalgemology.lemonsqueezy.com/checkout/buy/2d1ab55f-2bd6-4897-a4cd-f3320f54e99e)

Brilliance 23 · Fire 78 · Scintillation 74 · in our census, where the T73 scores 86 · 50 · 80 in tourmaline

How the Radiant Cut handles light in tourmaline, measured: brilliance 23, fire 78 and 73% leakage, set against the T73 in the same stone and against the same cut in diamond.

[Get the files](https://digitalgemology.com/gemstones/tourmaline/radiant#buy) [Open it in the Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=radiant&stone=tourmaline&ct=1.00&view=angle&lighting=studio&turn=0) [All cuts in tourmaline](https://digitalgemology.com/gemstones/tourmaline)

Light Return map of the Radiant Cut in tourmaline, face-up, from our own tracer at refractive index 1.603. Red, green and blue return light to the eye; gray leaks.

## Radiant Cut Tourmaline

Tourmaline has a refractive index of 1.603 to 1.655 and a dispersion of 0.017. Its critical angle, from the low end of that range, is 38.6°, so a round design needs a pavilion of at least 38.6° for head-on light to reflect off both sides of the pavilion and leave through the table. We trace it with one index, 1.629, the midpoint of the published range, and a fire spread of 0.015, 0.86 of the published dispersion. Every picture here is our Light Return tracer at 1.603, and every figure is from the same light census that scores the other gemstones; the 3D Gemstone Simulator shows the Radiant Cut in tourmaline live. Tourmaline is strongly doubly refractive (birefringence up to 0.040), so its back facets can look doubled. Our census traces one index (1.629), so the doubling is not in these figures.

The Radiant Cut has 74 facets and a total depth of 53.8% of its width. In tourmaline, the census returns 23 of 100 for brilliance and 78 for fire, against 86 and 50 for the T73, our benchmark, in the same stone; the same Radiant Cut in diamond reads 32 and 77.

## Is tourmaline good in a Radiant? Pros and cons, measured

### Pros

- [More fire than the T73 in tourmaline](https://digitalgemology.com/gemstones/tourmaline/radiant#pro-fire) 78 vs 50
- [Faces up larger for its weight](https://digitalgemology.com/gemstones/tourmaline/radiant#pro-faceup) 118 vs 100
- [Lighter than the same cut in diamond](https://digitalgemology.com/gemstones/tourmaline/radiant#pro-weight) 1.39 vs 1.56 ct

### Cons

- [Returns less light than the T73 in tourmaline](https://digitalgemology.com/gemstones/tourmaline/radiant#con-brilliance) 23 vs 86
- [Leaks more light than the T73 in tourmaline](https://digitalgemology.com/gemstones/tourmaline/radiant#con-leak) 73 vs 14
- [Fewer facets, less sparkle](https://digitalgemology.com/gemstones/tourmaline/radiant#con-scint) 74 vs 80

Compared with the T73 Round Brilliant in tourmaline and with the Radiant 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](https://digitalgemology.com/about/how-we-measure).

## All eight scores against the T73

At a glance: the Radiant Cut in tourmaline (white) against the T73 Round Brilliant in tourmaline (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 tourmaline: ahead on 3, behind on 5.

- Global 59, the comparison 78, difference −19
- Brilliance 23, the comparison 86, difference −63
- Fire 78, the comparison 50, difference +28
- Scintillation 74, the comparison 80, difference −6
- Spread 105, the comparison 100, difference +5
- Symmetry 99, the comparison 100, difference −1
- Shape-norm 26, the comparison 93, difference −67
- Tilt 100, the comparison 74, difference +26

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](https://digitalgemology.com/tools/cut-performance-wheel?cut=radiant&stone=tourmaline); these are the same census figures as our [Cut Performance Index](https://digitalgemology.com/learn/cut-performance-index).

## What the Radiant Cut gains in tourmaline

### More fire than the T73 in tourmaline

**Fire 78** against 50 for the T73 Round Brilliant in tourmaline: 28 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 (0.015 in tourmaline) and counts a ray as fire when the two directions differ by more than 0.6°. The Radiant Cut reads 78 against 50 for the T73 in tourmaline. The figure is the census's; the 3D Gemstone Simulator renders tourmaline'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](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=radiant&stone=tourmaline&ct=1.00&view=up&lighting=sun&turn=0): the Radiant Cut in tourmaline under the sunny-day lighting.

[Try it yourself: See the fire in the 3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=radiant&stone=tourmaline&ct=1.00&view=up&lighting=sun&turn=0)

### Faces up larger for its weight

**Face-up size 118** against 100 for the T73 Round Brilliant in tourmaline (T73 = 100): 18% more face-up area for the same weight

Face-up size is the outline's area per carat, measured from each model (T73 = 100): 118 for the Radiant 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.

*Face-up outline of the Radiant Cut at 1.00 ct in tourmaline: 7.18 x 3.92 mm, drawn to scale*

Radiant Cut · 7.18 x 3.92 mm at 1.00 ct · Face-up size 118

*Face-up outline of the T73 Round Brilliant at 1.00 ct in tourmaline: 6.74 mm, drawn to scale*

T73 Round Brilliant · 6.74 mm at 1.00 ct · Face-up size 100

Both stones weigh 1.00 ct in tourmaline 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.

[Try it yourself: See its size at 1.00 ct in tourmaline in the 3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=radiant&stone=tourmaline&ct=1.00&view=up&lighting=studio&turn=0)

### Lighter than the same cut in diamond

**1.39 ct** at 6.5 mm, against 1.56 ct for the same cut in diamond (−11%)

Weight follows specific gravity: 3.13 for tourmaline against 3.52 for diamond, so the same model at the same size weighs 1.39 ct here and 1.56 ct in diamond, 6.5 mm across. Nothing about the light changes with it.

*Weight of a 6.5 mm Radiant Cut: 1.39 ct in tourmaline, 1.56 ct in diamond*

A Radiant 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 Radiant Cut page](https://digitalgemology.com/cuts/radiant#stones)

## What the Radiant Cut gives up in tourmaline

### Returns less light than the T73 in tourmaline

**Brilliance 23** against 86 for the T73 Round Brilliant in tourmaline: 63 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 tourmaline, whose critical angle is 38.6°, the Radiant Cut returns 23 of 100 and the T73 86. The maps below show where each stone's light returns from and where it leaks.

Radiant Cut in tourmaline · Brilliance 23

T73 Round Brilliant in tourmaline · 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](https://digitalgemology.com/gemstones/tourmaline/dg-m5) reads 96 for brilliance in tourmaline, the best of the cuts we score there.

[Try it yourself: Open this Light Return map in the simulator](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=radiant&stone=tourmaline&ct=1.00&view=up&map=1&turn=0)

### Leaks more light than the T73 in tourmaline

**Leakage 73** against 14 for the T73 Round Brilliant in tourmaline: 59 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 Radiant Cut leaks 73% in tourmaline against 14% for the T73 in tourmaline. Grey in the maps below is leaking light; the share under each picture is that picture's own.

Radiant Cut in tourmaline · Leakage 73

0° · 74% leak

10° · 70% leak

20° · 66% leak

30° · 67% leak

T73 Round Brilliant in tourmaline · Leakage 14

0° · 10% leak

10° · 28% leak

20° · 32% leak

30° · 37% 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](https://digitalgemology.com/gemstones/tourmaline/dg-m5) reads 4% for leakage in tourmaline, the best of the cuts we score there.

[Try it yourself: Tilt it yourself in the simulator's light map](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=radiant&stone=tourmaline&ct=1.00&view=up&map=1&turn=0)

### Fewer facets, less sparkle

**Scintillation 74** against 80 for the T73 Round Brilliant in tourmaline: 6 points lower

Scintillation follows the number of facets the stone shows: 100 × (1 − e^(−facets / 45)). The Radiant Cut has 74 facets and the T73 73, so 74 against 80. It depends on the geometry alone, so it is the same in every stone.

*Facet diagram of the Radiant Cut: its crown, seen face-up, 74 facets in all*

Radiant Cut · 74 facets · Scintillation 74

*Facet diagram of the T73 Round Brilliant: its crown, seen face-up, 73 facets in all*

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](https://digitalgemology.com/gemstones/tourmaline/dg-miliano) reads 98 for scintillation in tourmaline, the best of the cuts we score there.

[Try it yourself: Compare the Scintillation spoke in the Cut Performance Wheel](https://digitalgemology.com/tools/cut-performance-wheel?cut=radiant&stone=tourmaline)

## Our verdict on the Radiant Cut in tourmaline

Pick the Radiant Cut in tourmaline for this: it shows more fire than the T73, faces up larger for its weight and weighs less than in diamond. The catch: it returns less light than the T73, leaks more light than the T73 and has fewer facets to sparkle with.

If that catch matters more to you, [the DG-M5](https://digitalgemology.com/gemstones/tourmaline/dg-m5) reads 96 for brilliance in tourmaline, 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 Radiant Cut model we traced.

## Radiant Cut Tourmaline: questions

### Is the Radiant a good cut for tourmaline?

In our census the Radiant Cut returns 23 of 100 for brilliance and 78 for fire in tourmaline, against 86 and 50 for the T73 in the same stone. Against that round and against the same cut in diamond it has 3 pros and 3 cons by our thresholds; the summary above names them.

### What pavilion angle does tourmaline need?

At least 38.6° for a round design: tourmaline's critical angle is 38.6°, 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.

### How much does a Radiant weigh in tourmaline?

At 6.5 mm across, 1.39 ct in tourmaline, against 1.56 ct for the same cut in diamond (-11%): tourmaline's specific gravity is 3.13, diamond's 3.52.

### Can I see the Radiant in tourmaline in 3D?

Yes: the 3D Gemstone Simulator renders it live, with tourmaline's own refractive index and dispersion. Tourmaline 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 Radiant Cut files

*6 formats* *Millimeters* *Watertight*

### Radiant Cut 3D files

The Radiant Cut as exact geometry: 74 planar facets, real-world scale, ready for CAD, rendering, printing and casting.

- **STEP** Exact faceted solid for CAD
- **3DM** Rhino, closed mesh on its own layer
- **STL** Watertight mesh for printing and casting
- **OBJ** Mesh for modeling and rendering
- **FBX** Blender, 3ds Max, Maya, Cinema 4D, Unity, Unreal
- **GLB** Web, AR and quick previews

€9.99 · [Personal use](https://digitalgemology.com/licence) [Buy the 3D files](https://digitalgemology.lemonsqueezy.com/checkout/buy/37db9344-72d1-4dac-89e9-88dc3539c639)

*In preparation*

### Radiant Cut cutting files

The faceting design for the Radiant Cut is in preparation. It will include the GemCad file, the tier table and a printable diagram.

Checkout opens soon Coming soon

Save with a bundle: the Radiant Cut 3D files are also in [Jewelry Essentials 3D](https://digitalgemology.com/cuts/#bundles), 10 cuts for €29.99 until 1 December, then €39.99 (€99.90 as single files). [Buy the bundle](https://digitalgemology.lemonsqueezy.com/checkout/buy/e5c79ed5-97ce-4c62-8dbe-3a172c6245ba?checkout%5Bdiscount_code%5D=BUNDLE25).

Not sure the files open in your software? [Get the cube free](https://digitalgemology.lemonsqueezy.com/checkout/buy/2d1ab55f-2bd6-4897-a4cd-f3320f54e99e): the same six formats, for your email address, used only to send them ([privacy](https://digitalgemology.com/privacy#free-sample)).

Questions before you buy? [Email us](mailto:support@digitalgemology.com).

## More gemstones and cuts

[Tourmaline: optical properties and the top ten cuts](https://digitalgemology.com/gemstones/tourmaline) · [The Radiant Cut: specifications, model and files](https://digitalgemology.com/cuts/radiant)

### Other cuts in tourmaline

- [T73 Round Brilliant](https://digitalgemology.com/gemstones/tourmaline/t73-round-brilliant)
- [T105 Round Brilliant](https://digitalgemology.com/gemstones/tourmaline/t105-round-brilliant)
- [DG-Vitruvio](https://digitalgemology.com/gemstones/tourmaline/dg-vitruvio)
- [DG-Anteros](https://digitalgemology.com/gemstones/tourmaline/dg-anteros)
- [DG-Broken Hearts and Arrows](https://digitalgemology.com/gemstones/tourmaline/dg-broken-hearts-and-arrows)
- [Baguette Cut](https://digitalgemology.com/gemstones/tourmaline/baguette)
- [Emerald Cut](https://digitalgemology.com/gemstones/tourmaline/emerald-cut)
- [Marquise Cut](https://digitalgemology.com/gemstones/tourmaline/marquise)
- [Oval Cut](https://digitalgemology.com/gemstones/tourmaline/oval)
- [Pear Cut](https://digitalgemology.com/gemstones/tourmaline/pear)
- [Rectangle Cut](https://digitalgemology.com/gemstones/tourmaline/rectangle)
- [Teardrop Cut](https://digitalgemology.com/gemstones/tourmaline/teardrop)
- [Asscher Cut](https://digitalgemology.com/gemstones/tourmaline/asscher)
- [Cushion Cut](https://digitalgemology.com/gemstones/tourmaline/cushion)
- [Emerald Square Cut](https://digitalgemology.com/gemstones/tourmaline/emerald-square)
- [Princess Cut](https://digitalgemology.com/gemstones/tourmaline/princess)
- [Radiant Square Cut](https://digitalgemology.com/gemstones/tourmaline/radiant-square)
- [Square Cut](https://digitalgemology.com/gemstones/tourmaline/square)
- [Triangle Cut](https://digitalgemology.com/gemstones/tourmaline/triangle)
- [Trilliant Cut](https://digitalgemology.com/gemstones/tourmaline/trilliant)
- [Trillion Cut](https://digitalgemology.com/gemstones/tourmaline/trillion)
- [Hexagon Cut](https://digitalgemology.com/gemstones/tourmaline/hexagon)
- [Octagon Cut](https://digitalgemology.com/gemstones/tourmaline/octagon)
- [Portuguese Bird's Nest Cut](https://digitalgemology.com/gemstones/tourmaline/portuguese-birds-nest)
- [Old Single Cut](https://digitalgemology.com/gemstones/tourmaline/old-single)
- [Mazarin Cut](https://digitalgemology.com/gemstones/tourmaline/mazarin)
- [Peruzzi Cut](https://digitalgemology.com/gemstones/tourmaline/peruzzi)
- [Old Mine Cut](https://digitalgemology.com/gemstones/tourmaline/old-mine)
- [Old European Cut](https://digitalgemology.com/gemstones/tourmaline/old-european)
- [T57 Round Brilliant](https://digitalgemology.com/gemstones/tourmaline/t57-round-brilliant)
- [DG-M5](https://digitalgemology.com/gemstones/tourmaline/dg-m5)
- [DG-Miliano](https://digitalgemology.com/gemstones/tourmaline/dg-miliano)
- [DG-Rafaello](https://digitalgemology.com/gemstones/tourmaline/dg-rafaello)
- [DG-Bowtie](https://digitalgemology.com/gemstones/tourmaline/dg-bowtie)
- [DG-Elongated Hexagon](https://digitalgemology.com/gemstones/tourmaline/dg-elongated-hexagon)
- [DG-Octagonal Kite](https://digitalgemology.com/gemstones/tourmaline/dg-octagonal-kite)

### The Radiant Cut in other gemstones

- [Diamond](https://digitalgemology.com/gemstones/diamond/radiant)
- [Moissanite](https://digitalgemology.com/gemstones/moissanite/radiant)
- [Cubic Zirconia](https://digitalgemology.com/gemstones/cubic-zirconia/radiant)
- [Ruby](https://digitalgemology.com/gemstones/ruby/radiant)
- [Sapphire](https://digitalgemology.com/gemstones/sapphire/radiant)
- [Emerald](https://digitalgemology.com/gemstones/emerald/radiant)
- [Amethyst](https://digitalgemology.com/gemstones/amethyst/radiant)
- [Topaz](https://digitalgemology.com/gemstones/topaz/radiant)
- [Spinel](https://digitalgemology.com/gemstones/spinel/radiant)
- [Demantoid](https://digitalgemology.com/gemstones/demantoid/radiant)
- [Zircon](https://digitalgemology.com/gemstones/zircon/radiant)
- [Peridot](https://digitalgemology.com/gemstones/peridot/radiant)
- [Tanzanite](https://digitalgemology.com/gemstones/tanzanite/radiant)
- [YAG](https://digitalgemology.com/gemstones/yag/radiant)
- [Pyrope](https://digitalgemology.com/gemstones/pyrope/radiant)
- [Almandine](https://digitalgemology.com/gemstones/almandine/radiant)
- [Spessartine](https://digitalgemology.com/gemstones/spessartine/radiant)
- [Grossular](https://digitalgemology.com/gemstones/grossular/radiant)
- [Chrysoberyl](https://digitalgemology.com/gemstones/chrysoberyl/radiant)
- [Kunzite](https://digitalgemology.com/gemstones/kunzite/radiant)
- [Iolite](https://digitalgemology.com/gemstones/iolite/radiant)
- [Morganite](https://digitalgemology.com/gemstones/morganite/radiant)
- [GGG](https://digitalgemology.com/gemstones/ggg/radiant)
- [Strontium titanate](https://digitalgemology.com/gemstones/strontium-titanate/radiant)
- [Synthetic rutile](https://digitalgemology.com/gemstones/synthetic-rutile/radiant)