--- title: "Oval Cut Demantoid: Pros, Cons and Scores" description: "Oval Cut in demantoid: brilliance 67, fire 97, leakage 20%, 3 pros and 4 cons against the T73, from our ray-traced light census." url: https://digitalgemology.com/gemstones/demantoid/oval image: https://digitalgemology.com/img/stone-cuts/oval-demantoid-og.jpg?v=931b044a --- > Markdown copy of https://digitalgemology.com/gemstones/demantoid/oval. 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 # Oval Cut Demantoid: more fire than the T73 in demantoid **Buy (instant download, personal-use license):** [Oval Cut 3D files, €9.99 · Personal use](https://digitalgemology.lemonsqueezy.com/checkout/buy/ce77b9f0-180a-4d41-b13f-f0b5f9e02b99) · [Oval Cut cutting files, €6.99 · Personal use](https://digitalgemology.lemonsqueezy.com/checkout/buy/b82abdce-69d2-46a4-819d-1a075b50fe92) · [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 67 · Fire 97 · Scintillation 87 · in our census, where the T73 scores 97 · 84 · 80 in demantoid How the Oval Cut handles light in demantoid, measured: brilliance 67, fire 97 and 20% leakage, set against the T73 in the same stone and against the same cut in diamond. [Get the files](https://digitalgemology.com/gemstones/demantoid/oval#buy) [Open it in the Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=oval&stone=demantoid&ct=1.00&view=angle&lighting=studio&turn=0) [All cuts in demantoid](https://digitalgemology.com/gemstones/demantoid) Light Return map of the Oval Cut in demantoid, face-up, from our own tracer at refractive index 1.881. Red, green and blue return light to the eye; gray leaks. ## Oval Cut Demantoid Demantoid has a refractive index of 1.881 to 1.888 and a dispersion of 0.057. Its critical angle, from the low end of that range, is 32.1°, so a round design needs a pavilion of at least 37.0° for head-on light to reflect off both sides of the pavilion and leave through the table. We trace it with one index, 1.885, the midpoint of the published range, and a fire spread of 0.049, 0.86 of the published dispersion. Every picture here is our Light Return tracer at 1.881, and every figure is from the same light census that scores the other gemstones; the 3D Gemstone Simulator shows the Oval Cut in demantoid live. The Oval Cut has 93 facets and a total depth of 64.0% of its width; its pavilion mains sit at 41.0°. In demantoid, the census returns 67 of 100 for brilliance and 97 for fire, against 97 and 84 for the T73, our benchmark, in the same stone; the same Oval Cut in diamond reads 47 and 92. ## Is demantoid good in an Oval? Pros and cons, measured ### Pros - [More fire than the T73 in demantoid](https://digitalgemology.com/gemstones/demantoid/oval#pro-fire) 97 vs 84 - [Faces up larger for its weight](https://digitalgemology.com/gemstones/demantoid/oval#pro-faceup) 108 vs 100 - [More facets, more sparkle](https://digitalgemology.com/gemstones/demantoid/oval#pro-scint) 87 vs 80 ### Cons - [Returns less light than the T73 in demantoid](https://digitalgemology.com/gemstones/demantoid/oval#con-brilliance) 67 vs 97 - [Loses more light when tilted than in diamond](https://digitalgemology.com/gemstones/demantoid/oval#con-tiltStab) 64 vs 92 - [Leaks more light than the T73 in demantoid](https://digitalgemology.com/gemstones/demantoid/oval#con-leak) 20 vs 3 - [Heavier than the same cut in diamond](https://digitalgemology.com/gemstones/demantoid/oval#con-weight) 1.56 vs 1.42 ct Compared with the T73 Round Brilliant in demantoid and with the Oval 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 Oval Cut in demantoid (white) against the T73 Round Brilliant in demantoid (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 demantoid: ahead on 2, behind on 6. - Global 79, the comparison 90, difference −11 - Brilliance 67, the comparison 97, difference −30 - Fire 97, the comparison 84, difference +13 - Scintillation 87, the comparison 80, difference +7 - Spread 99, the comparison 100, difference −1 - Symmetry 98, the comparison 100, difference −2 - Shape-norm 78, the comparison 104, difference −26 - Tilt 64, the comparison 79, difference −15 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=oval&stone=demantoid); these are the same census figures as our [Cut Performance Index](https://digitalgemology.com/learn/cut-performance-index). ## What the Oval Cut gains in demantoid ### More fire than the T73 in demantoid **Fire 97** against 84 for the T73 Round Brilliant in demantoid: 13 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 (0.049 in demantoid) and counts a ray as fire when the two directions differ by more than 0.6°. The Oval Cut reads 97 against 84 for the T73 in demantoid. The figure is the census's; the 3D Gemstone Simulator renders demantoid'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=oval&stone=demantoid&ct=1.00&view=up&lighting=sun&turn=0): the Oval Cut in demantoid under the sunny-day lighting. [Try it yourself: See the fire in the 3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=oval&stone=demantoid&ct=1.00&view=up&lighting=sun&turn=0) ### Faces up larger for its weight **Face-up size 108** against 100 for the T73 Round Brilliant in demantoid (T73 = 100): 8% more face-up area for the same weight Face-up size is the outline's area per carat, measured from each model (T73 = 100): 108 for the Oval 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 Oval Cut at 1.00 ct in demantoid: 7.47 x 5.61 mm, drawn to scale* Oval Cut · 7.47 x 5.61 mm at 1.00 ct · Face-up size 108 *Face-up outline of the T73 Round Brilliant at 1.00 ct in demantoid: 6.29 mm, drawn to scale* T73 Round Brilliant · 6.29 mm at 1.00 ct · Face-up size 100 Both stones weigh 1.00 ct in demantoid 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 demantoid in the 3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator?cut=oval&stone=demantoid&ct=1.00&view=up&lighting=studio&turn=0) ### More facets, more sparkle **Scintillation 87** against 80 for the T73 Round Brilliant in demantoid: 7 points higher Scintillation follows the number of facets the stone shows: 100 × (1 − e^(−facets / 45)). The Oval Cut has 93 facets and the T73 73, so 87 against 80. It depends on the geometry alone, so it is the same in every stone. *Facet diagram of the Oval Cut: its crown, seen face-up, 93 facets in all* Oval Cut · 93 facets · Scintillation 87 *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. [Try it yourself: Compare the Scintillation spoke in the Cut Performance Wheel](https://digitalgemology.com/tools/cut-performance-wheel?cut=oval&stone=demantoid) ## What the Oval Cut gives up in demantoid ### Returns less light than the T73 in demantoid **Brilliance 67** against 97 for the T73 Round Brilliant in demantoid: 30 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 demantoid, whose critical angle is 32.1°, the Oval Cut returns 67 of 100 and the T73 97. The Oval Cut's pavilion mains sit at 41.0°, the T73's at 40.8°. The maps below show where each stone's light returns from and where it leaks. Oval Cut in demantoid · Brilliance 67 T73 Round Brilliant in demantoid · Brilliance 97 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-Broken Hearts and Arrows](https://digitalgemology.com/gemstones/demantoid/dg-broken-hearts-and-arrows) reads 97 for brilliance in demantoid, 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=oval&stone=demantoid&ct=1.00&view=up&map=1&turn=0) ### Loses more light when tilted than in diamond **Tilt 64** against 92 for the Oval Cut in diamond: 28 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 Oval Cut keeps 64 against 92 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. Oval Cut in demantoid · Tilt 64 0° · 17% leak 10° · 23% leak 20° · 40% leak 30° · 52% leak Oval Cut in diamond · Tilt 92 0° · 31% leak 10° · 31% leak 20° · 32% leak 30° · 35% 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 DG-M5](https://digitalgemology.com/gemstones/demantoid/dg-m5) reads 89 for tilt in demantoid, 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=oval&stone=demantoid&vs=oval&vsstone=diamond) ### Leaks more light than the T73 in demantoid **Leakage 20** against 3 for the T73 Round Brilliant in demantoid: 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 Oval Cut leaks 20% in demantoid against 3% for the T73 in demantoid. Grey in the maps below is leaking light; the share under each picture is that picture's own. Oval Cut in demantoid · Leakage 20 0° · 17% leak 10° · 23% leak 20° · 40% leak 30° · 52% leak T73 Round Brilliant in demantoid · Leakage 3 0° · 1% leak 10° · 6% leak 20° · 17% leak 30° · 29% 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-Broken Hearts and Arrows](https://digitalgemology.com/gemstones/demantoid/dg-broken-hearts-and-arrows) reads 3% for leakage in demantoid, 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=oval&stone=demantoid&ct=1.00&view=up&map=1&turn=0) ### Heavier than the same cut in diamond **1.56 ct** at 6.5 mm, against 1.42 ct for the same cut in diamond (+9%) Weight follows specific gravity: 3.85 for demantoid against 3.52 for diamond, so the same model at the same size weighs 1.56 ct here and 1.42 ct in diamond, 6.5 mm across. Nothing about the light changes with it. *Weight of a 6.5 mm Oval Cut: 1.56 ct in demantoid, 1.42 ct in diamond* A Oval 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 Oval Cut page](https://digitalgemology.com/cuts/oval#stones) ## Our verdict on the Oval Cut in demantoid Pick the Oval Cut in demantoid for this: it shows more fire than the T73, faces up larger for its weight and has more facets to sparkle with. The catch: it returns less light than the T73, loses more light when tilted than in diamond, leaks more light than the T73 and weighs more than in diamond. If that catch matters more to you, [the DG-Broken Hearts and Arrows](https://digitalgemology.com/gemstones/demantoid/dg-broken-hearts-and-arrows) reads 97 for brilliance in demantoid, 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 Oval Cut model we traced. ## Oval Cut Demantoid: questions ### Is the Oval a good cut for demantoid? In our census the Oval Cut returns 67 of 100 for brilliance and 97 for fire in demantoid, against 97 and 84 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 demantoid need? At least 37.0° for a round design: demantoid's critical angle is 32.1°, 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 Oval Cut's pavilion mains sit at 41.0°. ### How much does a Oval weigh in demantoid? At 6.5 mm across, 1.56 ct in demantoid, against 1.42 ct for the same cut in diamond (+9%): demantoid's specific gravity is 3.85, diamond's 3.52. ### Can I see the Oval in demantoid in 3D? Yes: the 3D Gemstone Simulator renders it live, with demantoid's own refractive index and dispersion. Demantoid 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 Oval Cut files *6 formats* *Millimeters* *Watertight* ### Oval Cut 3D files The Oval Cut as exact geometry: 97 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/ce77b9f0-180a-4d41-b13f-f0b5f9e02b99) *GemCad* *96 index* ### Oval Cut cutting files The Oval Cut as a faceting design: 73 + 20 girdles = 93 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/b82abdce-69d2-46a4-819d-1a075b50fe92) Save with a bundle: the Oval 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 Oval 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 [Demantoid: optical properties and the top ten cuts](https://digitalgemology.com/gemstones/demantoid) · [The Oval Cut: specifications, model and files](https://digitalgemology.com/cuts/oval) ### Other cuts in demantoid - [T73 Round Brilliant](https://digitalgemology.com/gemstones/demantoid/t73-round-brilliant) - [T105 Round Brilliant](https://digitalgemology.com/gemstones/demantoid/t105-round-brilliant) - [DG-Vitruvio](https://digitalgemology.com/gemstones/demantoid/dg-vitruvio) - [DG-Anteros](https://digitalgemology.com/gemstones/demantoid/dg-anteros) - [DG-Broken Hearts and Arrows](https://digitalgemology.com/gemstones/demantoid/dg-broken-hearts-and-arrows) - [Baguette Cut](https://digitalgemology.com/gemstones/demantoid/baguette) - [Emerald Cut](https://digitalgemology.com/gemstones/demantoid/emerald-cut) - [Marquise Cut](https://digitalgemology.com/gemstones/demantoid/marquise) - [Pear Cut](https://digitalgemology.com/gemstones/demantoid/pear) - [Radiant Cut](https://digitalgemology.com/gemstones/demantoid/radiant) - [Rectangle Cut](https://digitalgemology.com/gemstones/demantoid/rectangle) - [Teardrop Cut](https://digitalgemology.com/gemstones/demantoid/teardrop) - [Asscher Cut](https://digitalgemology.com/gemstones/demantoid/asscher) - [Cushion Cut](https://digitalgemology.com/gemstones/demantoid/cushion) - [Emerald Square Cut](https://digitalgemology.com/gemstones/demantoid/emerald-square) - [Princess Cut](https://digitalgemology.com/gemstones/demantoid/princess) - [Radiant Square Cut](https://digitalgemology.com/gemstones/demantoid/radiant-square) - [Square Cut](https://digitalgemology.com/gemstones/demantoid/square) - [Triangle Cut](https://digitalgemology.com/gemstones/demantoid/triangle) - [Trilliant Cut](https://digitalgemology.com/gemstones/demantoid/trilliant) - [Trillion Cut](https://digitalgemology.com/gemstones/demantoid/trillion) - [Hexagon Cut](https://digitalgemology.com/gemstones/demantoid/hexagon) - [Octagon Cut](https://digitalgemology.com/gemstones/demantoid/octagon) - [Portuguese Bird's Nest Cut](https://digitalgemology.com/gemstones/demantoid/portuguese-birds-nest) - [Old Single Cut](https://digitalgemology.com/gemstones/demantoid/old-single) - [Mazarin Cut](https://digitalgemology.com/gemstones/demantoid/mazarin) - [Peruzzi Cut](https://digitalgemology.com/gemstones/demantoid/peruzzi) - [Old Mine Cut](https://digitalgemology.com/gemstones/demantoid/old-mine) - [Old European Cut](https://digitalgemology.com/gemstones/demantoid/old-european) - [T57 Round Brilliant](https://digitalgemology.com/gemstones/demantoid/t57-round-brilliant) - [DG-M5](https://digitalgemology.com/gemstones/demantoid/dg-m5) - [DG-Miliano](https://digitalgemology.com/gemstones/demantoid/dg-miliano) - [DG-Rafaello](https://digitalgemology.com/gemstones/demantoid/dg-rafaello) - [DG-Bowtie](https://digitalgemology.com/gemstones/demantoid/dg-bowtie) - [DG-Elongated Hexagon](https://digitalgemology.com/gemstones/demantoid/dg-elongated-hexagon) - [DG-Octagonal Kite](https://digitalgemology.com/gemstones/demantoid/dg-octagonal-kite) ### The Oval Cut in other gemstones - [Diamond](https://digitalgemology.com/gemstones/diamond/oval) - [Cubic Zirconia](https://digitalgemology.com/gemstones/cubic-zirconia/oval) - [Ruby](https://digitalgemology.com/gemstones/ruby/oval) - [Sapphire](https://digitalgemology.com/gemstones/sapphire/oval) - [Emerald](https://digitalgemology.com/gemstones/emerald/oval) - [Amethyst](https://digitalgemology.com/gemstones/amethyst/oval) - [Moissanite](https://digitalgemology.com/gemstones/moissanite/oval) - [Topaz](https://digitalgemology.com/gemstones/topaz/oval) - [Spinel](https://digitalgemology.com/gemstones/spinel/oval) - [Zircon](https://digitalgemology.com/gemstones/zircon/oval) - [Tourmaline](https://digitalgemology.com/gemstones/tourmaline/oval) - [Peridot](https://digitalgemology.com/gemstones/peridot/oval) - [Tanzanite](https://digitalgemology.com/gemstones/tanzanite/oval) - [YAG](https://digitalgemology.com/gemstones/yag/oval) - [Pyrope](https://digitalgemology.com/gemstones/pyrope/oval) - [Almandine](https://digitalgemology.com/gemstones/almandine/oval) - [Spessartine](https://digitalgemology.com/gemstones/spessartine/oval) - [Grossular](https://digitalgemology.com/gemstones/grossular/oval) - [Chrysoberyl](https://digitalgemology.com/gemstones/chrysoberyl/oval) - [Kunzite](https://digitalgemology.com/gemstones/kunzite/oval) - [Iolite](https://digitalgemology.com/gemstones/iolite/oval) - [Morganite](https://digitalgemology.com/gemstones/morganite/oval) - [GGG](https://digitalgemology.com/gemstones/ggg/oval) - [Strontium titanate](https://digitalgemology.com/gemstones/strontium-titanate/oval) - [Synthetic rutile](https://digitalgemology.com/gemstones/synthetic-rutile/oval)