From Surf Wiki (app.surf) — the open knowledge base
Snub polyhedron
Polyhedron resulting from the snub operation
Polyhedron resulting from the snub operation
In geometry, a snub polyhedron is a polyhedron obtained by performing a snub operation: alternating a corresponding omnitruncated or truncated polyhedron, depending on the definition. Some, but not all, authors include antiprisms as snub polyhedra, as they are obtained by this construction from a degenerate "polyhedron" with only two faces (a dihedron).
Chiral snub polyhedra do not always have reflection symmetry and hence sometimes have two enantiomorphous (left- and right-handed) forms which are reflections of each other. Their symmetry groups are all point groups.
For example, the snub cube:
| [[File:Snubhexahedronccw.gif | 100px]] | [[File:Snubhexahedroncw.gif | 100px]] |
|---|
Snub polyhedra have Wythoff symbol p q r and by extension, vertex configuration 3.p.3.q.3.r. Retrosnub polyhedra (a subset of the snub polyhedron, containing the great icosahedron, small retrosnub icosicosidodecahedron, and great retrosnub icosidodecahedron) still have this form of Wythoff symbol, but their vertex configurations are instead
List of snub polyhedra
Uniform
There are 12 uniform snub polyhedra, not including the antiprisms, the icosahedron as a snub tetrahedron, the great icosahedron as a retrosnub tetrahedron and the great disnub dirhombidodecahedron, also known as Skilling's figure.
When the Schwarz triangle of the snub polyhedron is isosceles, the snub polyhedron is not chiral. This is the case for the antiprisms, the icosahedron, the great icosahedron, the small snub icosicosidodecahedron, and the small retrosnub icosicosidodecahedron.
In the pictures of the snub derivation (showing a distorted snub polyhedron, topologically identical to the uniform version, arrived at from geometrically alternating the parent uniform omnitruncated polyhedron) where green is not present, the faces derived from alternation are coloured red and yellow, while the snub triangles are blue. Where green is present (only for the snub icosidodecadodecahedron and great snub dodecicosidodecahedron), the faces derived from alternation are red, yellow, and blue, while the snub triangles are green.
| Snub polyhedron | Image | Original omnitruncated polyhedron | Image | Snub derivation | Symmetry group | Wythoff symbol | |||
|---|---|---|---|---|---|---|---|---|---|
| Vertex description | |||||||||
| Icosahedron (snub tetrahedron) | [[File:Snub tetrahedron.png | 100px]] | Truncated octahedron | [[File:Omnitruncated tetrahedron.png | 100px]] | [[File:Snub-polyhedron-icosahedron.png | 100px]] | Ih (Th) | 3 3 2 |
| 3.3.3.3.3 | |||||||||
| Great icosahedron (retrosnub tetrahedron) | [[File:Retrosnub tetrahedron.png | 100px]] | Truncated octahedron | [[File:Omnitruncated tetrahedron.png | 100px]] | [[File:Snub-polyhedron-great-icosahedron.png | 100px]] | Ih (Th) | 2 3/2 3/2 |
| (3.3.3.3.3)/2 | |||||||||
| Snub cubeor snub cuboctahedron | [[File:Snub hexahedron.png | 100px]] | Truncated cuboctahedron | [[File:Great rhombicuboctahedron.png | 100px]] | [[File:Snub-polyhedron-snub-cube.png | 100px]] | O | 4 3 2 |
| 3.3.3.3.4 | |||||||||
| Snub dodecahedronor snub icosidodecahedron | [[File:Snub dodecahedron ccw.png | 100px]] | Truncated icosidodecahedron | [[File:Great rhombicosidodecahedron.png | 100px]] | [[File:Snub-polyhedron-snub-dodecahedron.png | 100px]] | I | 5 3 2 |
| 3.3.3.3.5 | |||||||||
| Small snub icosicosidodecahedron | [[File:Small snub icosicosidodecahedron.png | 100px]] | Doubly covered truncated icosahedron | [[File:Truncated icosahedron.png | 100px]] | [[File:Snub-polyhedron-small-snub-icosicosidodecahedron.png | 100px]] | Ih | 3 3 5/2 |
| 3.3.3.3.3.5/2 | |||||||||
| Snub dodecadodecahedron | [[File:Snub dodecadodecahedron.png | 100px]] | Small rhombidodecahedron with extra 12{10/2} faces | [[File:Omnitruncated great dodecahedron with blue decagon and yellow square.svg | 100px]] | [[File:Snub-polyhedron-snub-dodecadodecahedron.png | 100px]] | I | 5 5/2 2 |
| 3.3.5/2.3.5 | |||||||||
| Snub icosidodecadodecahedron | [[File:Snub icosidodecadodecahedron.png | 100px]] | Icositruncated dodecadodecahedron | [[File:Icositruncated dodecadodecahedron.png | 100px]] | [[File:Snub-polyhedron-snub-icosidodecadodecahedron.png | 100px]] | I | 5 3 5/3 |
| 3.5/3.3.3.3.5 | |||||||||
| Great snub icosidodecahedron | [[File:Great snub icosidodecahedron.png | 100px]] | Rhombicosahedron with extra 12{10/2} faces | [[File:Omnitruncated great icosahedron with blue hexagon and yellow square.svg | 100px]] | [[File:Snub-polyhedron-great-snub-icosidodecahedron.png | 100px]] | I | 3 5/2 2 |
| 3.3.5/2.3.3 | |||||||||
| Inverted snub dodecadodecahedron | [[File:Inverted snub dodecadodecahedron.png | 100px]] | Truncated dodecadodecahedron | [[File:Truncated dodecadodecahedron.png | 100px]] | [[File:Snub-polyhedron-inverted-snub-dodecadodecahedron.png | 100px]] | I | 5 2 5/3 |
| 3.5/3.3.3.3.5 | |||||||||
| Great snub dodecicosidodecahedron | [[File:Great snub dodecicosidodecahedron.png | 100px]] | Great dodecicosahedron with extra 12{10/2} faces | [[File:Great dodecicosahedron.png | 100px]] | no image yet | I | 3 5/2 5/3 | |
| 3.5/3.3.5/2.3.3 | |||||||||
| Great inverted snub icosidodecahedron | [[File:Great inverted snub icosidodecahedron.png | 100px]] | Great truncated icosidodecahedron | [[File:Great truncated icosidodecahedron.png | 100px]] | [[File:Snub-polyhedron-great-inverted-snub-icosidodecahedron.png | 100px]] | I | 3 2 5/3 |
| 3.5/3.3.3.3 | |||||||||
| Small retrosnub icosicosidodecahedron | [[File:Small retrosnub icosicosidodecahedron.png | 100px]] | Doubly covered truncated icosahedron | [[File:Truncated icosahedron.png | 100px]] | no image yet | Ih | 5/2 3/2 3/2 | |
| (3.3.3.3.3.5/2)/2 | |||||||||
| Great retrosnub icosidodecahedron | [[File:Great retrosnub icosidodecahedron.png | 100px]] | Great rhombidodecahedron with extra 20{6/2} faces | [[File:Great rhombidodecahedron.png | 100px]] | no image yet | I | 2 5/3 3/2 | |
| (3.3.3.5/2.3)/2 | |||||||||
| Great dirhombicosidodecahedron | [[File:Great dirhombicosidodecahedron.png | 100px]] | — | — | — | Ih | 3/2 5/3 3 5/2 | ||
| (4.3/2.4.5/3.4.3.4.5/2)/2 | |||||||||
| Great disnub dirhombidodecahedron | [[File:Great disnub dirhombidodecahedron.png | 100px]] | — | — | — | Ih | (3/2) 5/3 (3) 5/2 | ||
| (3/2.3/2.3/2.4.5/3.4.3.3.3.4.5/2.4)/2 |
Notes:
- The icosahedron, snub cube and snub dodecahedron are the only three convex ones. They are obtained by snubification of the truncated octahedron, truncated cuboctahedron and the truncated icosidodecahedron - the three convex truncated quasiregular polyhedra.
- The only snub polyhedron with the chiral octahedral group of symmetries is the snub cube.
- Only the icosahedron and the great icosahedron are also regular polyhedra. They are also deltahedra.
- Only the icosahedron, great icosahedron, small snub icosicosidodecahedron, small retrosnub icosicosidodecahedron, great dirhombicosidodecahedron, and great disnub dirhombidodecahedron also have reflective symmetries.
There is also the infinite set of antiprisms. They are formed from prisms, which are truncated hosohedra, degenerate regular polyhedra. Those up to hexagonal are listed below. In the pictures showing the snub derivation, the faces derived from alternation (of the prism bases) are coloured red, and the snub triangles are coloured yellow. The exception is the tetrahedron, for which all the faces are derived as red snub triangles, as alternating the square bases of the cube results in degenerate digons as faces.
| Snub polyhedron | Image | Original omnitruncated polyhedron | Image | Snub derivation | Symmetry group | Wythoff symbol | |||
|---|---|---|---|---|---|---|---|---|---|
| Vertex description | |||||||||
| Tetrahedron | [[File:Linear antiprism.png | 100px]] | Cube | [[File:Uniform polyhedron 222-t012.png | 100px]] | [[File:Snub-polyhedron-tetrahedron.png | 100px]] | Td (D2d) | 2 2 2 |
| 3.3.3 | |||||||||
| Octahedron | [[File:Trigonal antiprism.png | 100px]] | Hexagonal prism | [[File:Uniform polyhedron-23-t012.png | 100px]] | [[File:Snub-polyhedron-octahedron.png | 100px]] | Oh (D3d) | 3 2 2 |
| 3.3.3.3 | |||||||||
| Square antiprism | [[File:Square antiprism.png | 100px]] | Octagonal prism | [[File:Octagonal prism.png | 100px]] | [[File:Snub-polyhedron-square-antiprism.png | 100px]] | D4d | 4 2 2 |
| 3.4.3.3 | |||||||||
| Pentagonal antiprism | [[File:Pentagonal antiprism.png | 100px]] | Decagonal prism | [[File:Decagonal prism.png | 100px]] | [[File:Snub-polyhedron-pentagonal-antiprism.png | 100px]] | D5d | 5 2 2 |
| 3.5.3.3 | |||||||||
| Pentagrammic antiprism | [[File:Pentagrammic antiprism.png | 100px]] | Doubly covered pentagonal prism | [[File:Pentagonal prism.png | 100px]] | [[File:Snub-polyhedron-pentagrammic-antiprism.png | 100px]] | D5h | 5/2 2 2 |
| 3.5/2.3.3 | |||||||||
| Pentagrammic crossed-antiprism | [[File:Pentagrammic crossed antiprism.png | 100px]] | Decagrammic prism | [[File:Prism 10-3.png | 100px]] | [[File:Snub-polyhedron-pentagrammic-crossed-antiprism.png | 100px]] | D5d | 2 2 5/3 |
| 3.5/3.3.3 | |||||||||
| Hexagonal antiprism | [[File:Hexagonal antiprism.png | 100px]] | Dodecagonal prism | [[File:Dodecagonal prism.png | 100px]] | [[File:Snub-polyhedron-hexagonal-antiprism.png | 100px]] | D6d | 6 2 2 |
| 3.6.3.3 |
Notes:
- Two of these polyhedra may be constructed from the first two snub polyhedra in the list starting with the icosahedron: the pentagonal antiprism is a parabidiminished icosahedron and a pentagrammic crossed-antiprism is a parabidiminished great icosahedron, also known as a parabireplenished great icosahedron.
Non-uniform
Two Johnson solids are snub polyhedra: the snub disphenoid and the snub square antiprism. Neither is chiral.
| Snub polyhedron | Image | Original polyhedron | Image | Symmetry group | ||
|---|---|---|---|---|---|---|
| Snub disphenoid | [[File:Snub disphenoid.png | 100px]] | Disphenoid | [[File:Disphenoid tetrahedron.png | 100px]] | D2d |
| Snub square antiprism | [[File:Snub square antiprism.png | 100px]] | Square antiprism | [[File:Square antiprism.png | 100px]] | D4d |
Bibliography
- Mäder, R. E. Uniform Polyhedra. Mathematica J. 3, 48-57, 1993.
This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.
Ask Mako anything about Snub polyhedron — get instant answers, deeper analysis, and related topics.
Research with MakoFree with your Surf account
Create a free account to save articles, ask Mako questions, and organize your research.
Sign up freeThis content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.
Report