---
title: "Rectangle Cut Tanzanite: Pros, Cons and Scores"
description: "Rectangle Cut in tanzanite: brilliance 39, fire 63, leakage 56%, 3 pros and 3 cons against the T73, from our ray-traced light census."
url: https://digitalgemology.com/gemstones/tanzanite/rectangle
image: https://digitalgemology.com/img/stone-cuts/rectangle-tanzanite-og.jpg?v=d8348faf
---

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# Rectangle Cut Tanzanite: faces up larger for its weight

**Buy (instant download, personal-use license):** [Rectangle Cut 3D files, €9.99 · Personal use](https://digitalgemology.lemonsqueezy.com/checkout/buy/1e627cbe-69a3-44f0-a5da-e5cab29131b8) · [Rectangle Cut cutting files, €6.99 · Personal use](https://digitalgemology.lemonsqueezy.com/checkout/buy/1d8e7f45-2f16-44f2-8215-0aea13e29c3b) · [Get the cube free](https://digitalgemology.lemonsqueezy.com/checkout/buy/2d1ab55f-2bd6-4897-a4cd-f3320f54e99e)

Brilliance 39 · Fire 63 · Scintillation 63 · in our census, where the T73 scores 92 · 47 · 80 in tanzanite

How the Rectangle Cut handles light in tanzanite, measured: brilliance 39, fire 63 and 56% leakage, set against the T73 in the same stone and against the same cut in diamond.

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

Light Return map of the Rectangle Cut in tanzanite, face-up, from our own tracer at refractive index 1.685. Red, green and blue return light to the eye; gray leaks.

## Rectangle Cut Tanzanite

Tanzanite has a refractive index of 1.685 to 1.707 and a dispersion of 0.019. Its critical angle, from the low end of that range, is 36.4°, so a round design needs a pavilion of at least 36.4° for head-on light to reflect off both sides of the pavilion and leave through the table. We trace it with one index, 1.696, the midpoint of the published range, and a fire spread of 0.016, 0.86 of the published dispersion. Every picture here is our Light Return tracer at 1.685, and every figure is from the same light census that scores the other gemstones; the 3D Gemstone Simulator shows the Rectangle Cut in tanzanite live.

The Rectangle Cut has 45 facets and a total depth of 62.0% of its width; its pavilion mains sit at 33.5°. In tanzanite, the census returns 39 of 100 for brilliance and 63 for fire, against 92 and 47 for the T73, our benchmark, in the same stone; the same Rectangle Cut in diamond reads 50 and 77.

## Is tanzanite good in a Rectangle? Pros and cons, measured

### Pros

- [Faces up larger for its weight](https://digitalgemology.com/gemstones/tanzanite/rectangle#pro-faceup) 121 vs 100
- [More fire than the T73 in tanzanite](https://digitalgemology.com/gemstones/tanzanite/rectangle#pro-fire) 63 vs 47
- [Lighter than the same cut in diamond](https://digitalgemology.com/gemstones/tanzanite/rectangle#pro-weight) 2.00 vs 2.10 ct

### Cons

- [Returns less light than the T73 in tanzanite](https://digitalgemology.com/gemstones/tanzanite/rectangle#con-brilliance) 39 vs 92
- [Leaks more light than the T73 in tanzanite](https://digitalgemology.com/gemstones/tanzanite/rectangle#con-leak) 56 vs 8
- [Fewer facets, less sparkle](https://digitalgemology.com/gemstones/tanzanite/rectangle#con-scint) 63 vs 80

Compared with the T73 Round Brilliant in tanzanite and with the Rectangle 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 Rectangle Cut in tanzanite (white) against the T73 Round Brilliant in tanzanite (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 tanzanite: ahead on 2, level on 2, behind on 4.

- Global 60, the comparison 80, difference −20
- Brilliance 39, the comparison 92, difference −53
- Fire 63, the comparison 47, difference +16
- Scintillation 63, the comparison 80, difference −17
- Spread 100, the comparison 100, difference 0
- Symmetry 100, the comparison 100, difference 0
- Shape-norm 51, the comparison 99, difference −48
- Tilt 86, the comparison 73, difference +13

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

## What the Rectangle Cut gains in tanzanite

### Faces up larger for its weight

**Face-up size 121** against 100 for the T73 Round Brilliant in tanzanite (T73 = 100): 21% more face-up area for the same weight

Face-up size is the outline's area per carat, measured from each model (T73 = 100): 121 for the Rectangle 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 Rectangle Cut at 1.00 ct in tanzanite: 7.76 x 5.16 mm, drawn to scale*

Rectangle Cut · 7.76 x 5.16 mm at 1.00 ct · Face-up size 121

*Face-up outline of the T73 Round Brilliant at 1.00 ct in tanzanite: 6.58 mm, drawn to scale*

T73 Round Brilliant · 6.58 mm at 1.00 ct · Face-up size 100

Both stones weigh 1.00 ct in tanzanite 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 tanzanite in the 3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=rectangle&stone=tanzanite&ct=1.00&view=up&lighting=studio&turn=0)

### More fire than the T73 in tanzanite

**Fire 63** against 47 for the T73 Round Brilliant in tanzanite: 16 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 (0.016 in tanzanite) and counts a ray as fire when the two directions differ by more than 0.6°. The Rectangle Cut reads 63 against 47 for the T73 in tanzanite. The figure is the census's; the 3D Gemstone Simulator renders tanzanite'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=rectangle&stone=tanzanite&ct=1.00&view=up&lighting=sun&turn=0): the Rectangle Cut in tanzanite under the sunny-day lighting.

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

### Lighter than the same cut in diamond

**2.00 ct** at 6.5 mm, against 2.10 ct for the same cut in diamond (−5%)

Weight follows specific gravity: 3.35 for tanzanite against 3.52 for diamond, so the same model at the same size weighs 2.00 ct here and 2.10 ct in diamond, 6.5 mm across. Nothing about the light changes with it.

*Weight of a 6.5 mm Rectangle Cut: 2.00 ct in tanzanite, 2.10 ct in diamond*

A Rectangle 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 Rectangle Cut page](https://digitalgemology.com/cuts/rectangle#stones)

## What the Rectangle Cut gives up in tanzanite

### Returns less light than the T73 in tanzanite

**Brilliance 39** against 92 for the T73 Round Brilliant in tanzanite: 53 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 tanzanite, whose critical angle is 36.4°, the Rectangle Cut returns 39 of 100 and the T73 92. The Rectangle Cut's pavilion mains sit at 33.5°, the T73's at 40.8°. The maps below show where each stone's light returns from and where it leaks.

Rectangle Cut in tanzanite · Brilliance 39

T73 Round Brilliant in tanzanite · Brilliance 92

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/tanzanite/dg-m5) reads 100 for brilliance in tanzanite, 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=rectangle&stone=tanzanite&ct=1.00&view=up&map=1&turn=0)

### Leaks more light than the T73 in tanzanite

**Leakage 56** against 8 for the T73 Round Brilliant in tanzanite: 48 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 Rectangle Cut leaks 56% in tanzanite against 8% for the T73 in tanzanite. Grey in the maps below is leaking light; the share under each picture is that picture's own.

Rectangle Cut in tanzanite · Leakage 56

0° · 56% leak

10° · 60% leak

20° · 64% leak

30° · 65% leak

T73 Round Brilliant in tanzanite · Leakage 8

0° · 9% leak

10° · 19% leak

20° · 30% leak

30° · 32% 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/tanzanite/dg-m5) reads 0% for leakage in tanzanite, 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=rectangle&stone=tanzanite&ct=1.00&view=up&map=1&turn=0)

### Fewer facets, less sparkle

**Scintillation 63** against 80 for the T73 Round Brilliant in tanzanite: 17 points lower

Scintillation follows the number of facets the stone shows: 100 × (1 − e^(−facets / 45)). The Rectangle Cut has 45 facets and the T73 73, so 63 against 80. It depends on the geometry alone, so it is the same in every stone.

*Facet diagram of the Rectangle Cut: its crown, seen face-up, 45 facets in all*

Rectangle Cut · 45 facets · Scintillation 63

*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/tanzanite/dg-miliano) reads 98 for scintillation in tanzanite, 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=rectangle&stone=tanzanite)

## Our verdict on the Rectangle Cut in tanzanite

Pick the Rectangle Cut in tanzanite for this: it faces up larger for its weight, shows more fire than the T73 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/tanzanite/dg-m5) reads 100 for brilliance in tanzanite, 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 Rectangle Cut model we traced.

## Rectangle Cut Tanzanite: questions

### Is the Rectangle a good cut for tanzanite?

In our census the Rectangle Cut returns 39 of 100 for brilliance and 63 for fire in tanzanite, against 92 and 47 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 tanzanite need?

At least 36.4° for a round design: tanzanite's critical angle is 36.4°, 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 Rectangle Cut's pavilion mains sit at 33.5°.

### How much does a Rectangle weigh in tanzanite?

At 6.5 mm across, 2.00 ct in tanzanite, against 2.10 ct for the same cut in diamond (-5%): tanzanite's specific gravity is 3.35, diamond's 3.52.

### Can I see the Rectangle in tanzanite in 3D?

Yes: the 3D Gemstone Simulator renders it live, with tanzanite's own refractive index and dispersion. Tanzanite 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 Rectangle Cut files

*6 formats* *Millimeters* *Watertight*

### Rectangle Cut 3D files

The Rectangle Cut as exact geometry: 45 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/1e627cbe-69a3-44f0-a5da-e5cab29131b8)

*GemCad* *96 index*

### Rectangle Cut cutting files

The Rectangle Cut as a faceting design: 41 + 4 girdles = 45 facets, 96 index, 2-fold mirror-image symmetry, ready for the machine.

- **.asc** GemCad design file, 96 index gear
- **.csv** Tier table: angles, indices and cutting order
- **Diagram** Printable faceting diagram

€6.99 · [Personal use](https://digitalgemology.com/licence) [Buy the cutting files](https://digitalgemology.lemonsqueezy.com/checkout/buy/1d8e7f45-2f16-44f2-8215-0aea13e29c3b)

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

[Tanzanite: optical properties and the top ten cuts](https://digitalgemology.com/gemstones/tanzanite) · [The Rectangle Cut: specifications, model and files](https://digitalgemology.com/cuts/rectangle)

### Other cuts in tanzanite

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

### The Rectangle Cut in other gemstones

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