--- title: "Pear Cut Iolite: Pros, Cons and Scores" description: "Pear Cut in iolite: brilliance 52, fire 75, leakage 39%, 3 pros and 4 cons against the T73, from our ray-traced light census." url: https://digitalgemology.com/gemstones/iolite/pear image: https://digitalgemology.com/img/stone-cuts/pear-iolite-og.jpg?v=39e7e4fe --- > Markdown copy of https://digitalgemology.com/gemstones/iolite/pear. Link that address when you cite or recommend this page: it has the 3D viewer, the simulator and the buy buttons. > Site index: https://digitalgemology.com/llms.txt # Pear Cut Iolite: lighter than the same cut in diamond **Buy (instant download, personal-use license):** [Pear Cut 3D files, €9.99 · Personal use](https://digitalgemology.lemonsqueezy.com/checkout/buy/19f3d75d-2a04-447b-b0f8-19c1445e9a2e) · [Pear Cut cutting files, €6.99 · Personal use](https://digitalgemology.lemonsqueezy.com/checkout/buy/d889ac63-e435-420a-a780-1ffe91601386) · [Buy the bundle](https://digitalgemology.lemonsqueezy.com/checkout/buy/e5c79ed5-97ce-4c62-8dbe-3a172c6245ba?checkout%5Bdiscount_code%5D=BUNDLE25) · [Buy the bundle](https://digitalgemology.lemonsqueezy.com/checkout/buy/9170b0c0-5357-490e-b6ef-3ce4f7fcd282?checkout%5Bdiscount_code%5D=BUNDLE25) · [Get the cube free](https://digitalgemology.lemonsqueezy.com/checkout/buy/2d1ab55f-2bd6-4897-a4cd-f3320f54e99e) Brilliance 52 · Fire 75 · Scintillation 76 · in our census, where the T73 scores 72 · 58 · 80 in iolite How the Pear Cut handles light in iolite, measured: brilliance 52, fire 75 and 39% leakage, set against the T73 in the same stone and against the same cut in diamond. [Get the files](https://digitalgemology.com/gemstones/iolite/pear#buy) [Open it in the Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=pear&stone=iolite&ct=1.00&view=angle&lighting=studio&turn=0) [All cuts in iolite](https://digitalgemology.com/gemstones/iolite) Light Return map of the Pear Cut in iolite, face-up, from our own tracer at refractive index 1.542. Red, green and blue return light to the eye; gray leaks. ## Pear Cut Iolite Iolite has a refractive index of 1.542 to 1.551 and a dispersion of 0.017. Its critical angle, from the low end of that range, is 40.4°, so a round design needs a pavilion of at least 40.4° for head-on light to reflect off both sides of the pavilion and leave through the table. We trace it with one index, 1.547, 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 1.542, and every figure is from the same light census that scores the other gemstones; the 3D Gemstone Simulator shows the Pear Cut in iolite live. The Pear Cut has 64 facets and a total depth of 60.0% of its width; its pavilion mains sit at 34.9°. In iolite, the census returns 52 of 100 for brilliance and 75 for fire, against 72 and 58 for the T73, our benchmark, in the same stone; the same Pear Cut in diamond reads 53 and 84. ## Is iolite good in a Pear? Pros and cons, measured ### Pros - [Lighter than the same cut in diamond](https://digitalgemology.com/gemstones/iolite/pear#pro-weight) 1.01 vs 1.37 ct - [More fire than the T73 in iolite](https://digitalgemology.com/gemstones/iolite/pear#pro-fire) 75 vs 58 - [Faces up larger for its weight](https://digitalgemology.com/gemstones/iolite/pear#pro-faceup) 115 vs 100 ### Cons - [Loses more of its light when tilted](https://digitalgemology.com/gemstones/iolite/pear#con-tiltStab) 56 vs 81 - [Returns less light than the T73 in iolite](https://digitalgemology.com/gemstones/iolite/pear#con-brilliance) 52 vs 72 - [Leaks more in iolite than in diamond](https://digitalgemology.com/gemstones/iolite/pear#con-leak) 39 vs 22 - [A less regular pavilion than the T73](https://digitalgemology.com/gemstones/iolite/pear#con-symm) 85 vs 100 Compared with the T73 Round Brilliant in iolite and with the Pear 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 Pear Cut in iolite (white) against the T73 Round Brilliant in iolite (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 iolite: ahead on 2, behind on 6. - Global 64, the comparison 74, difference −10 - Brilliance 52, the comparison 72, difference −20 - Fire 75, the comparison 58, difference +17 - Scintillation 76, the comparison 80, difference −4 - Spread 101, the comparison 100, difference +1 - Symmetry 85, the comparison 100, difference −15 - Shape-norm 60, the comparison 77, difference −17 - Tilt 56, the comparison 81, difference −25 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=pear&stone=iolite); these are the same census figures as our [Cut Performance Index](https://digitalgemology.com/learn/cut-performance-index). ## What the Pear Cut gains in iolite ### Lighter than the same cut in diamond **1.01 ct** at 6.5 mm, against 1.37 ct for the same cut in diamond (−26%) Weight follows specific gravity: 2.61 for iolite against 3.52 for diamond, so the same model at the same size weighs 1.01 ct here and 1.37 ct in diamond, 6.5 mm across. Nothing about the light changes with it. *Weight of a 6.5 mm Pear Cut: 1.01 ct in iolite, 1.37 ct in diamond* A Pear 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 Pear Cut page](https://digitalgemology.com/cuts/pear#stones) ### More fire than the T73 in iolite **Fire 75** against 58 for the T73 Round Brilliant in iolite: 17 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 iolite) and counts a ray as fire when the two directions differ by more than 0.6°. The Pear Cut reads 75 against 58 for the T73 in iolite. The figure is the census's; the 3D Gemstone Simulator renders iolite'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=pear&stone=iolite&ct=1.00&view=up&lighting=sun&turn=0): the Pear Cut in iolite under the sunny-day lighting. [Try it yourself: See the fire in the 3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=pear&stone=iolite&ct=1.00&view=up&lighting=sun&turn=0) ### Faces up larger for its weight **Face-up size 115** against 100 for the T73 Round Brilliant in iolite (T73 = 100): 15% more face-up area for the same weight Face-up size is the outline's area per carat, measured from each model (T73 = 100): 115 for the Pear 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 Pear Cut at 1.00 ct in iolite: 9.72 x 6.47 mm, drawn to scale* Pear Cut · 9.72 x 6.47 mm at 1.00 ct · Face-up size 115 *Face-up outline of the T73 Round Brilliant at 1.00 ct in iolite: 7.15 mm, drawn to scale* T73 Round Brilliant · 7.15 mm at 1.00 ct · Face-up size 100 Both stones weigh 1.00 ct in iolite 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 iolite in the 3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=pear&stone=iolite&ct=1.00&view=up&lighting=studio&turn=0) ## What the Pear Cut gives up in iolite ### Loses more of its light when tilted **Tilt 56** against 81 for the T73 Round Brilliant in iolite: 25 points lower 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 Pear Cut keeps 56 against 81 for the T73. The tilt strips below show the maps at 0°, 10°, 20° and 30°, with each picture's own leak share under it. Pear Cut in iolite · Tilt 56 0° · 33% leak 10° · 35% leak 20° · 27% leak 30° · 40% leak T73 Round Brilliant in iolite · Tilt 81 0° · 13% leak 10° · 38% leak 20° · 36% leak 30° · 44% 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. **What helps:** [the T105 Round Brilliant](https://digitalgemology.com/gemstones/iolite/t105-round-brilliant) reads 87 for tilt in iolite, the best of the cuts we score there. [Try it yourself: Compare the Tilt spoke in the Cut Performance Wheel](https://digitalgemology.com/tools/cut-performance-wheel?cut=pear&stone=iolite) ### Returns less light than the T73 in iolite **Brilliance 52** against 72 for the T73 Round Brilliant in iolite: 20 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 iolite, whose critical angle is 40.4°, the Pear Cut returns 52 of 100 and the T73 72. The Pear Cut's pavilion mains sit at 34.9°, the T73's at 40.8°. The maps below show where each stone's light returns from and where it leaks. Pear Cut in iolite · Brilliance 52 T73 Round Brilliant in iolite · Brilliance 72 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/iolite/dg-m5) reads 85 for brilliance in iolite, 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=pear&stone=iolite&ct=1.00&view=up&map=1&turn=0) ### Leaks more in iolite than in diamond **Leakage 39** against 22 for the Pear Cut in diamond: 17 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 Pear Cut leaks 39% in iolite against 22% for the same cut in diamond. Grey in the maps below is leaking light; the share under each picture is that picture's own. Pear Cut in iolite · Leakage 39 0° · 33% leak 10° · 35% leak 20° · 27% leak 30° · 40% leak Pear Cut in diamond · Leakage 22 0° · 25% leak 10° · 24% leak 20° · 28% leak 30° · 25% 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/iolite/dg-m5) reads 15% for leakage in iolite, 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=pear&stone=iolite&ct=1.00&view=up&map=1&turn=0) ### A less regular pavilion than the T73 **Symmetry 85** against 100 for the T73 Round Brilliant in iolite: 15 points lower Symmetry reads how evenly the pavilion facets of each design family are cut: 100 − 6 × their scatter in degrees. The Pear Cut reads 85, the T73 100. It depends on the geometry alone, so it is the same in every stone. *Facet diagram of the Pear Cut: its pavilion, seen from below, 64 facets in all* Pear Cut · 64 facets · Symmetry 85 *Facet diagram of the T73 Round Brilliant: its pavilion, seen from below, 73 facets in all* T73 Round Brilliant · 73 facets · Symmetry 100 Symmetry scores how regular the pavilion facets are within the design. Compare how evenly the facets repeat around each pavilion. Drawn from each cut's own model. [Try it yourself: Compare the Symmetry spoke in the Cut Performance Wheel](https://digitalgemology.com/tools/cut-performance-wheel?cut=pear&stone=iolite) ## Our verdict on the Pear Cut in iolite Pick the Pear Cut in iolite for this: it weighs less than in diamond, shows more fire than the T73 and faces up larger for its weight. The catch: it loses more of its light when tilted, returns less light than the T73, leaks more than in diamond and has a less regular pavilion than the T73. If that catch matters more to you, [the T105 Round Brilliant](https://digitalgemology.com/gemstones/iolite/t105-round-brilliant) reads 87 for tilt in iolite, 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 Pear Cut model we traced. ## Pear Cut Iolite: questions ### Is the Pear a good cut for iolite? In our census the Pear Cut returns 52 of 100 for brilliance and 75 for fire in iolite, against 72 and 58 for the T73 in the same stone. Against that round and against the same cut in diamond it has 3 pros and 4 cons by our thresholds; the summary above names them. ### What pavilion angle does iolite need? At least 40.4° for a round design: iolite's critical angle is 40.4°, 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 Pear Cut's pavilion mains sit at 34.9°. ### How much does a Pear weigh in iolite? At 6.5 mm across, 1.01 ct in iolite, against 1.37 ct for the same cut in diamond (-26%): iolite's specific gravity is 2.61, diamond's 3.52. ### Can I see the Pear in iolite in 3D? Yes: the 3D Gemstone Simulator renders it live, with iolite's own refractive index and dispersion. Iolite 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 Pear Cut files *6 formats* *Millimeters* *Watertight* ### Pear Cut 3D files The Pear Cut as exact geometry: 64 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/19f3d75d-2a04-447b-b0f8-19c1445e9a2e) *GemCad* *64 index* ### Pear Cut cutting files The Pear Cut as a faceting design: 50 + 14 girdles = 64 facets, 64 index, 1-fold mirror-image symmetry, ready for the machine. - **.asc** GemCad design file, 64 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/d889ac63-e435-420a-a780-1ffe91601386) Save with a bundle: the Pear 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). Save with a bundle: the Pear Cut cutting files are also in [Faceter's Classics](https://digitalgemology.com/cuts/#bundles), 10 cuts for €22.49 until 1 December, then €29.99 (€69.90 as single files). [Buy the bundle](https://digitalgemology.lemonsqueezy.com/checkout/buy/9170b0c0-5357-490e-b6ef-3ce4f7fcd282?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 [Iolite: optical properties and the top ten cuts](https://digitalgemology.com/gemstones/iolite) · [The Pear Cut: specifications, model and files](https://digitalgemology.com/cuts/pear) ### Other cuts in iolite - [T73 Round Brilliant](https://digitalgemology.com/gemstones/iolite/t73-round-brilliant) - [T105 Round Brilliant](https://digitalgemology.com/gemstones/iolite/t105-round-brilliant) - [DG-Vitruvio](https://digitalgemology.com/gemstones/iolite/dg-vitruvio) - [DG-Anteros](https://digitalgemology.com/gemstones/iolite/dg-anteros) - [DG-Broken Hearts and Arrows](https://digitalgemology.com/gemstones/iolite/dg-broken-hearts-and-arrows) - [Baguette Cut](https://digitalgemology.com/gemstones/iolite/baguette) - [Emerald Cut](https://digitalgemology.com/gemstones/iolite/emerald-cut) - [Marquise Cut](https://digitalgemology.com/gemstones/iolite/marquise) - [Oval Cut](https://digitalgemology.com/gemstones/iolite/oval) - [Radiant Cut](https://digitalgemology.com/gemstones/iolite/radiant) - [Rectangle Cut](https://digitalgemology.com/gemstones/iolite/rectangle) - [Teardrop Cut](https://digitalgemology.com/gemstones/iolite/teardrop) - [Asscher Cut](https://digitalgemology.com/gemstones/iolite/asscher) - [Cushion Cut](https://digitalgemology.com/gemstones/iolite/cushion) - [Emerald Square Cut](https://digitalgemology.com/gemstones/iolite/emerald-square) - [Princess Cut](https://digitalgemology.com/gemstones/iolite/princess) - [Radiant Square Cut](https://digitalgemology.com/gemstones/iolite/radiant-square) - [Square Cut](https://digitalgemology.com/gemstones/iolite/square) - [Triangle Cut](https://digitalgemology.com/gemstones/iolite/triangle) - [Trilliant Cut](https://digitalgemology.com/gemstones/iolite/trilliant) - [Trillion Cut](https://digitalgemology.com/gemstones/iolite/trillion) - [Hexagon Cut](https://digitalgemology.com/gemstones/iolite/hexagon) - [Octagon Cut](https://digitalgemology.com/gemstones/iolite/octagon) - [Portuguese Bird's Nest Cut](https://digitalgemology.com/gemstones/iolite/portuguese-birds-nest) - [Old Single Cut](https://digitalgemology.com/gemstones/iolite/old-single) - [Mazarin Cut](https://digitalgemology.com/gemstones/iolite/mazarin) - [Peruzzi Cut](https://digitalgemology.com/gemstones/iolite/peruzzi) - [Old Mine Cut](https://digitalgemology.com/gemstones/iolite/old-mine) - [Old European Cut](https://digitalgemology.com/gemstones/iolite/old-european) - [T57 Round Brilliant](https://digitalgemology.com/gemstones/iolite/t57-round-brilliant) - [DG-M5](https://digitalgemology.com/gemstones/iolite/dg-m5) - [DG-Miliano](https://digitalgemology.com/gemstones/iolite/dg-miliano) - [DG-Rafaello](https://digitalgemology.com/gemstones/iolite/dg-rafaello) - [DG-Bowtie](https://digitalgemology.com/gemstones/iolite/dg-bowtie) - [DG-Elongated Hexagon](https://digitalgemology.com/gemstones/iolite/dg-elongated-hexagon) - [DG-Octagonal Kite](https://digitalgemology.com/gemstones/iolite/dg-octagonal-kite) ### The Pear Cut in other gemstones - [Ruby](https://digitalgemology.com/gemstones/ruby/pear) - [Sapphire](https://digitalgemology.com/gemstones/sapphire/pear) - [Emerald](https://digitalgemology.com/gemstones/emerald/pear) - [Amethyst](https://digitalgemology.com/gemstones/amethyst/pear) - [Diamond](https://digitalgemology.com/gemstones/diamond/pear) - [Moissanite](https://digitalgemology.com/gemstones/moissanite/pear) - [Cubic Zirconia](https://digitalgemology.com/gemstones/cubic-zirconia/pear) - [Topaz](https://digitalgemology.com/gemstones/topaz/pear) - [Spinel](https://digitalgemology.com/gemstones/spinel/pear) - [Demantoid](https://digitalgemology.com/gemstones/demantoid/pear) - [Zircon](https://digitalgemology.com/gemstones/zircon/pear) - [Tourmaline](https://digitalgemology.com/gemstones/tourmaline/pear) - [Peridot](https://digitalgemology.com/gemstones/peridot/pear) - [Tanzanite](https://digitalgemology.com/gemstones/tanzanite/pear) - [YAG](https://digitalgemology.com/gemstones/yag/pear) - [Pyrope](https://digitalgemology.com/gemstones/pyrope/pear) - [Almandine](https://digitalgemology.com/gemstones/almandine/pear) - [Spessartine](https://digitalgemology.com/gemstones/spessartine/pear) - [Grossular](https://digitalgemology.com/gemstones/grossular/pear) - [Chrysoberyl](https://digitalgemology.com/gemstones/chrysoberyl/pear) - [Kunzite](https://digitalgemology.com/gemstones/kunzite/pear) - [Morganite](https://digitalgemology.com/gemstones/morganite/pear) - [GGG](https://digitalgemology.com/gemstones/ggg/pear) - [Strontium titanate](https://digitalgemology.com/gemstones/strontium-titanate/pear) - [Synthetic rutile](https://digitalgemology.com/gemstones/synthetic-rutile/pear)