List of Johnson solids

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In geometry, a convex polyhedron whose faces are regular polygons is known as a Johnson solid, or sometimes as a Johnson–Zalgaller solid.[1] Some authors exclude uniform polyhedra (in which all vertices are symmetric to each other) from the definition; uniform polyhedra include Platonic and Archimedean solids as well as prisms and antiprisms.[2] The Johnson solids are named after American mathematician Norman Johnson (1930–2017), who published a list of 92 non-uniform Johnson polyhedra in 1966. His conjecture that the list was complete and no other examples existed was proven by Russian-Israeli mathematician Victor Zalgaller (1920–2020) in 1969.[3]

This article lists the 92 non-uniform Johnson solids, accompanied by images. They are listed alongside their basic elements (vertices, edges, and faces), and their most important general characteristics, including symmetry groups (Cn, Dn, Cnv, Dnh, Dnd, Cs), order, surface area, and volume; an overview of these follows first, before presenting the complete list of non-uniform Johnson solids.

Characteristics

Every polyhedron has its own characteristics, including symmetry and measurement. An object is said to have symmetry if there is a transformation that maps it to itself. All of those transformations may be composed in a group, alongside the group's number of elements, known as the order. In two-dimensional space, these transformations include rotating around the center of a polygon and reflecting an object around the perpendicular bisector of a polygon. The mensuration of polyhedra includes the surface area and volume. An area is a two-dimensional measurement calculated by the product of length and width; for a polyhedron, the surface area is the sum of the areas of all of its faces.[4] A volume is a measurement of a region in three-dimensional space.[5] The volume of a polyhedron may be ascertained in different ways: either through its base and height (like for pyramids and prisms), by slicing it off into pieces and summing their individual volumes, or by finding the root of a polynomial representing the polyhedron.[6]

A polygon that is rotated symmetrically by 360n is denoted by Cn, a cyclic group of order n; combining this with the reflection symmetry results in the symmetry of dihedral group Dn of order 2n.[7] In three-dimensional symmetry point groups, the transformations preserving a polyhedron's symmetry include the rotation around the line passing through the base center, known as the axis of symmetry, and the reflection relative to perpendicular planes passing through the bisector of a base, which is known as the pyramidal symmetry Cnv of order 2n. The transformation that preserves a polyhedron's symmetry by reflecting it across a horizontal plane is known as the prismatic symmetry Dnh of order 4n. The antiprismatic symmetry Dnd of order 4n preserves the symmetry by rotating its half bottom and reflection across the horizontal plane.[8] The symmetry group Cnh of order 2n preserves the symmetry by rotation around the axis of symmetry and reflection on the horizontal plane; the specific case preserving the symmetry by one full rotation is C1h of order 2, often denoted as Cs.[9] Page Template:Row hover highlight/styles.css has no content.Template:Sticky-headerTemplate:Sort-under

The solids

Seventeen Johnson solids may be categorized as elementary polyhedra, meaning they cannot be separated by a plane to create two small convex polyhedra with regular faces. The first six Johnson solids satisfy this criterion: the equilateral square pyramid, pentagonal pyramid, triangular cupola, square cupola, pentagonal cupola, and pentagonal rotunda. The criterion is also satisfied by eleven other Johnson solids, specifically the tridiminished icosahedron, parabidiminished rhombicosidodecahedron, tridiminished rhombicosidodecahedron, snub disphenoid, snub square antiprism, sphenocorona, sphenomegacorona, hebesphenomegacorona, disphenocingulum, bilunabirotunda, and triangular hebesphenorotunda.[10] The rest of the Johnson solids are not elementary, and they are constructed using the first six Johnson solids together with Platonic and Archimedean solids in various processes. Augmentation involves attaching the Johnson solids onto one or more faces of polyhedra, while elongation or gyroelongation involve joining them onto the bases of a prism or antiprism, respectively. Some others are constructed by diminishment, the removal of one of the first six solids from one or more of a polyhedron's faces.[11]

The table below lists the 92 (non-uniform) Johnson solids. The table includes each solid's enumeration (denoted as Jn).[12] It also includes each solid's symmetry group and number of vertices, edges, and faces, as well as its surface area and volume when constructed with edge length 1.

Table of the 92 Johnson solids
Jn Solid name Image Vertices Edges Faces Symmetry group and its order[13] Surface area, exact, with edge length 1[14] Surface area, approximate, with edge length 1[14] Volume, exact, with edge length 1[14] Volume, approximate, with edge length 1[14]
1 Square pyramid 100px 5 8 5 C4v of order 8 1+3 2.7321 26 0.2357
2 Pentagonal pyramid 100px 6 10 6 C5v of order 10 1252(10+5+75+305) 3.8855 5+524 0.3015
3 Triangular cupola 100px 9 15 8 C3v of order 6 3+532 7.3301 532 1.1785
4 Square cupola 100px 12 20 10 C4v of order 8 7+22+3 11.5605 1+223 1.9428
5 Pentagonal cupola 100px 15 25 12 C5v of order 10 20+53+725+31054 16.5798 5+456 2.3241
6 Pentagonal rotunda 100px 20 35 17 C5v of order 10 53+650+29052 22.3472 45+17512 6.9178
7 Elongated triangular pyramid 100px 7 12 7 C3v of order 6 3+3 4.7321 2+3312 0.5509
8 Elongated square pyramid 100px 9 16 9 C4v of order 8 5+3 6.7321 1+26 1.2357
9 Elongated pentagonal pyramid 100px 11 20 11 C5v of order 10 20+53+25+1054 8.8855 5+5+625+10524 2.022
10 Gyroelongated square pyramid 100px 9 20 13 C4v of order 8 1+33 6.1962 2+24+326 1.1927
11 Gyroelongated pentagonal pyramid 100px 11 25 16 C5v of order 10 153+25+1054 8.2157 25+9524 1.8802
12 Triangular bipyramid 100px 5 9 6 D3h of order 12 332 2.5981 26 0.2357
13 Pentagonal bipyramid 100px 7 15 10 D5h of order 20 532 4.3301 5+512 0.6030
14 Elongated triangular bipyramid 100px 8 15 9 D3h of order 12 3+332 5.5981 26+34 0.6687
15 Elongated square bipyramid 100px 10 20 12 D4h of order 16 4+23 7.4641 1+23 1.4714
16 Elongated pentagonal bipyramid 100px 12 25 15 D5h of order 20 5+523 9.3301 5+5+325+10512 2.3235
17 Gyroelongated square bipyramid 100px 10 24 16 D4d of order 16 43 6.9282 2+4+323 1.4284
18 Elongated triangular cupola 100px 15 27 14 C3v of order 6 9+523 13.3301 52+936 3.7766
19 Elongated square cupola 100px 20 36 18 C4v of order 8 15+22+3 19.5605 3+823 6.7712
20 Elongated pentagonal cupola 100px 25 45 22 C5v of order 10 60+53+105+25+25+1054 26.5798 5+45+155+256 10.0183
21 Elongated pentagonal rotunda 100px 30 55 27 C5v of order 10 20+53+55+25+325+1052 32.3472 45+175+305+2512 14.612
22 Gyroelongated triangular cupola 100px 15 33 20 C3v of order 6 3+1123 12.5263 13612+183+301+3 3.5161
23 Gyroelongated square cupola 100px 20 44 26 C4v of order 8 7+22+53 18.4887 1+232+234+22+2146+1032 6.2108
24 Gyroelongated pentagonal cupola 100px 25 55 32 C5v of order 10 5+253+105+25+25+1054 25.2400 56+235+562650+2905252 9.0733
25 Gyroelongated pentagonal rotunda 100px 30 65 37 C5v of order 10 153+(5+35)5+252 31.0075 45+175+102650+290525212 13.6671
26 Gyrobifastigium 100px 8 14 8 D2d of order 8 4+3 5.7321 32 0.8660
27 Triangular orthobicupola 100px 12 24 14 D3h of order 12 6+23 9.4641 523 2.3570
28 Square orthobicupola 100px 16 32 18 D4h of order 16 10+23 13.4641 2+423 3.8856
29 Square gyrobicupola 100px 16 32 18 D4d of order 16
30 Pentagonal orthobicupola 100px 20 40 22 D5h of order 20 10+51+5+75+30510 17.7711 5+453 4.6481
31 Pentagonal gyrobicupola 100px 20 40 22 D5d of order 20
32 Pentagonal orthocupolarotunda 100px 25 50 27 C5v of order 10 5+141900+4905+21075+305 23.5385 55+25512 9.2418
33 Pentagonal gyrocupolarotunda 100px 25 50 27 C5v of order 10 5+1543+7425+105 23.5385
34 Pentagonal orthobirotunda 100px 30 60 32 D5h of order 20 53+325+105 29.306 45+1756 13.8355
35 Elongated triangular orthobicupola 100px 18 36 20 D3h of order 12 12+23 15.4641 523+332 4.9551
36 Elongated triangular gyrobicupola 100px 18 36 20 D3d of order 12
37 Elongated square gyrobicupola 100px 24 48 26 D4d of order 16 18+23 21.4641 4+1023 8.714
38 Elongated pentagonal orthobicupola 100px 30 60 32 D5h of order 20 20+51+5+75+30510 27.7711 10+85+155+256 12.3423
39 Elongated pentagonal gyrobicupola 100px 30 60 32 D5d of order 20
40 Elongated pentagonal orthocupolarotunda 100px 35 70 37 C5v of order 10 15+141900+4905+21075+305 33.5385 55+255+305+2512 16.936
41 Elongated pentagonal gyrocupolarotunda 100px 35 70 37 C5v of order 10
42 Elongated pentagonal orthobirotunda 100px 40 80 42 D5h of order 20 10+300+905+3075+305 39.306 45+175+155+256 21.5297
43 Elongated pentagonal gyrobirotunda 100px 40 80 42 D5d of order 20
44 Gyroelongated triangular bicupola 100px 18 42 26 D3 of order 6 6+53 14.6603 532+2+23 4.6946
45 Gyroelongated square bicupola 100px 24 56 34 D4 of order 8 10+63 20.3923 2+432+234+22+2146+1032 8.1536
46 Gyroelongated pentagonal bicupola 100px 30 70 42 D5 of order 10 10+1523+1225+105 26.4313 5+453+562650+2905252 11.3974
47 Gyroelongated pentagonal cupolarotunda 100px 35 80 47 C5 of order 5 5+74(53+25+105) 32.1988 55+25512+562650+2905252 15.9911
48 Gyroelongated pentagonal birotunda 100px 40 90 52 D5 of order 10 103+325+105 37.9662 45+175+52650+29052526 20.5848
49 Augmented triangular prism 100px 7 13 8 C2v of order 4 2+323 4.5981 26+34 0.6687
50 Biaugmented triangular prism 100px 8 17 11 C2v of order 4 1+523 5.3301 59144+16 0.9044
51 Triaugmented triangular prism 100px 9 21 14 D3h of order 12 732 6.0622 22+34 1.1401
52 Augmented pentagonal prism 100px 11 19 10 C2v of order 4 4+3+1225+105 9.173 112233+905+1250+205 1.9562
53 Biaugmented pentagonal prism 100px 12 23 13 C2v of order 4 3+23+1225+105 9.9051 112257+905+2450+205 2.1919
54 Augmented hexagonal prism 100px 13 22 11 C2v of order 4 5+43 11.9282 26+332 2.8338
55 Parabiaugmented hexagonal prism 100px 14 26 14 D2h of order 8 4+53 12.6603 23+332 3.0695
56 Metabiaugmented hexagonal prism 100px 14 26 14 C2v of order 4
57 Triaugmented hexagonal prism 100px 15 30 17 D3h of order 12 3+63 13.3923 12+332 3.3052
58 Augmented dodecahedron 100px 21 35 16 C5v of order 10 53+1125+1054 21.0903 95+43524 7.9646
59 Parabiaugmented dodecahedron 100px 22 40 20 D5d of order 20 52(3+25+105) 21.5349 25+1156 8.2661
60 Metabiaugmented dodecahedron 100px 22 40 20 C2v of order 4
61 Triaugmented dodecahedron 100px 23 45 24 C3v of order 6 34(53+325+105) 21.9795 58(7+35) 8.5676
62 Metabidiminished icosahedron 100px 10 20 12 C2v of order 4 53+25+1052 7.7711 5+256 1.5787
63 Tridiminished icosahedron 100px 9 15 8 C3v of order 6 53+325+1054 7.3265 58+7524 1.2772
64 Augmented tridiminished icosahedron 100px 10 18 10 C3v of order 6 73+325+1054 8.1925 15+22+7524 1.3950
65 Augmented truncated tetrahedron 100px 15 27 14 C3v of order 6 3+1323 14.2583 1122 3.8891
66 Augmented truncated cube 100px 28 48 22 C4v of order 8 15+102+33 34.3383 8+1623 15.5425
67 Biaugmented truncated cube 100px 32 60 30 D4h of order 16 18+82+43 36.2419 9+62 17.4853
68 Augmented truncated dodecahedron 100px 65 105 42 C5v of order 10 5+253+1105+25+25+1054 102.1821 50512+8154 87.3637
69 Parabiaugmented truncated dodecahedron 100px 70 120 52 D5d of order 20 10+255+25+153+25+1052 103.3734 515+251512 89.6878
70 Metabiaugmented truncated dodecahedron 100px 70 120 52 C2v of order 4
71 Triaugmented truncated dodecahedron 100px 75 135 62 C3v of order 6 15+353+905+25+325+1054 104.5648 712(75+375) 92.0118
72 Gyrate rhombicosidodecahedron 100px 60 120 62 C5v of order 10 30+53+325+105 59.306 20+2953 41.6153
73 Parabigyrate rhombicosidodecahedron 100px 60 120 62 D5d of order 20
74 Metabigyrate rhombicosidodecahedron 100px 60 120 62 C2v of order 4
75 Trigyrate rhombicosidodecahedron 100px 60 120 62 C3v of order 6
76 Diminished rhombicosidodecahedron 100px 55 105 52 C5v of order 10 25+153+105+25+1125+1054 58.1147 1156+95 39.2913
77 Paragyrate diminished rhombicosidodecahedron 100px 55 105 52 C5v of order 10
78 Metagyrate diminished rhombicosidodecahedron 100px 55 105 52 Cs of order 2
79 Bigyrate diminished rhombicosidodecahedron 100px 55 105 52 Cs of order 2
80 Parabidiminished rhombicosidodecahedron 100px 50 90 42 D5d of order 20 20+52(3+25+25+25+105) 56.9233 55+2553 36.9672
81 Metabidiminished rhombicosidodecahedron 100px 50 90 42 C2v of order 4
82 Gyrate bidiminished rhombicosidodecahedron 100px 50 90 42 Cs of order 2
83 Tridiminished rhombicosidodecahedron 100px 45 75 32 C3v of order 6 15+53+305+25+925+1054 55.732 352+2353 34.6432
84 Snub disphenoid 100px 8 18 12 D2d of order 8 33 5.1962   0.8595
85 Snub square antiprism 100px 16 40 26 D4d of order 16 2+63 12.3923   3.6012
86 Sphenocorona 100px 10 22 14 C2v of order 4 2+33 7.1962 121+332+13+36 1.5154
87 Augmented sphenocorona 100px 11 26 17 Cs of order 2 1+43 7.9282 121+332+13+36+132 1.7511
88 Sphenomegacorona 100px 12 28 18 C2v of order 4 2+43 8.9282   1.9481
89 Hebesphenomegacorona 100px 14 33 21 C2v of order 4 3+923 10.7942   2.9129
90 Disphenocingulum 100px 16 38 24 D2d of order 8 4+53 12.6603   3.7776
91 Bilunabirotunda 100px 14 26 14 D2h of order 8 2+23+25+105 12.346 17+9512 3.0937
92 Triangular hebesphenorotunda 100px 18 36 20 C3v of order 6 3+193+325+1054 16.3887 52+756 5.1087

References

  1. Araki, Horiyama & Uehara (2015).
  2. Walsh (2014), p. 284.
  3. Parker (1997), p. 264.
  4. Flusser, Suk & Zitofa (2017), p. 126.
  5. Uehara (2020), p. 62.
  6. Johnson (1966).
  7. 14.0 14.1 14.2 14.3 Berman (1971).

Bibliography