In geometry, a Johnson solid, sometimes also known as a Johnson–Zalgaller solid, is a convex polyhedron whose faces are regular polygons and that is not a uniform polyhedron. There are 92 such solids:
A convex polyhedron is the convex hull of a finite set of points in 3-dimensional space, not all in a plane. Its boundary is a finite union of polygons, no two in the same plane; those polygons are called the faces. A Johnson solid is a convex polyhedron whose faces are all regular polygons, but not a uniform polyhedron; the last condition excludes the Platonic solids, Archimedean solids, prisms, and antiprisms.
The solids are named after Norman Johnson and Victor Zalgaller. Johnson (1966) published a list of 92 such solids and assigned them their names and numbers. Zalgaller (1969) proved Johnson's conjecture that there were none beyond these 92.[non-primary source needed]
A convex polyhedron in which all faces are nearly regular, but some are not precisely regular, is known as a near-miss Johnson solid.
- invalid, - Platonic, - Archimedean, - Gyrated sections.
The naming of Johnson solids follows a flexible and precise descriptive formula that allows many solids to be named in multiple different ways without compromising the accuracy of each name as a description. The names of the Johnson solids are described in the following sections.
The first 48 Johnson solids are constructed from pyramids, cupolas, or rotundas, combined with prisms or antiprisms. The following prefixes are attached to the word to indicate specific combinations of shapes:
Using this nomenclature, a pentagonal bipyramid is a solid constructed by attaching two bases of pentagonal pyramids. Triangular orthobicupola is constructed by two triangular cupolas along their bases.
Excluded solids: - coplanar, - Platonic, - Archimedean.
| Fastigium | |
|---|---|
| gyrobi- | 26 Gyrobifastigium |
The next 35 Johnson solids are constructed by modifying uniform polyhedra such as prisms, Platonic, or Archimedean solids by adding, subtracting, or rotating pyramids or cupolas. The following prefixes are attached to the word to indicate additions, subtractions, or rotations:
The three operations—augmentation, diminution, and gyration—can be performed multiple times for certain large solids. Bi- & Tri- indicate a double and triple operation respectively. For example, a bigyrate solid has two rotated cupolas, and a tridiminished solid has three removed pyramids or cupolas. In certain large solids, a distinction is made between solids where altered faces are parallel and solids where altered faces are oblique. Para- indicates the former, that the solid in question has altered parallel faces, and meta- the latter, altered oblique faces. For example, a parabiaugmented solid has had two parallel faces augmented, and a metabigyrate solid has had two oblique cupolas gyrated.

The last 9 Johnson solids have names based on certain polygon complexes from which they are assembled. These names are defined by Johnson with the following nomenclature:
| Snub polyhedra | |
|---|---|
| 84 Snub disphenoid |
85 Snub square antiprism |
| Formed from lunes and triangles | |
| 86 Sphenocorona |
87 Augmented sphenocorona |
| 88 Sphenomegacorona |
89 Hebesphenomegacorona |
| 90 Disphenocingulum | |
| Rotundoids | |
| 91 Bilunabirotunda |
92 Triangular hebesphenorotunda |
Five Johnson solids are deltahedra, with only triangle faces.
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 criterion is also satisfied by eleven other Johnson solids:
The five gyroelongated bicupolas or birotundas are chiral and have distinct left-handed and right-handed forms.
Twenty five of the Johnson solids have vertices that exist on the surface of a sphere. All of them can be seen to be related to a Platonic or Archimedean solid by gyration, diminishment, or dissection.
| Octahedron | Icosahedron | |||
|---|---|---|---|---|
| J1 |
J2 |
J11 |
J62 |
J63 |
| Cuboctahedron | Rhombicuboctahedron | Icosidodecahedron | ||||
|---|---|---|---|---|---|---|
| J3 |
J27 |
J4 |
J19 |
J37 |
J6 |
J34 |
| Rhombicosidodecahedron | ||||||
| J5 |
J72 |
J73 |
J74 |
J75 |
J76 |
J77 |
| J78 |
J79 |
J80 |
J81 |
J82 |
J83 | |
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. A volume is a measurement of a region in three-dimensional space. 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.
A polygon that is rotated symmetrically by is denoted by , a cyclic group of order ; combining this with the reflection symmetry results in the symmetry of dihedral group of order . 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 of order . The transformation that preserves a polyhedron's symmetry by reflecting it across a horizontal plane is known as the prismatic symmetry of order . The antiprismatic symmetry of order preserves the symmetry by rotating its half bottom and reflection across the horizontal plane. The symmetry group of order 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 of order 2, often denoted as .
The table below lists the properties of the 92 (non-uniform) Johnson solids. The table includes each solid's enumeration (denoted as ). 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. For simplicity, the table uses the quantity .
| Solid name | Image | Vertices | Edges | Faces | Symmetry group and order | Surface area, exact | Surface area, approx. |
Volume, exact | Volume, approx. | |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Square pyramid | 5 | 8 | 5 | of order 8 | 2.7321 | 0.2357 | |||
| 2 | Pentagonal pyramid | 6 | 10 | 6 | of order 10 | 3.8855 | 0.3015 | |||
| 3 | Triangular cupola | 9 | 15 | 8 | of order 6 | 7.3301 | 1.1785 | |||
| 4 | Square cupola | 12 | 20 | 10 | of order 8 | 11.5605 | 1.9428 | |||
| 5 | Pentagonal cupola | 15 | 25 | 12 | of order 10 | 16.5798 | 2.3241 | |||
| 6 | Pentagonal rotunda | 20 | 35 | 17 | of order 10 | 22.3472 | 6.9178 | |||
| 7 | Elongated triangular pyramid | 7 | 12 | 7 | of order 6 | 4.7321 | 0.5509 | |||
| 8 | Elongated square pyramid | 9 | 16 | 9 | of order 8 | 6.7321 | 1.2357 | |||
| 9 | Elongated pentagonal pyramid | 11 | 20 | 11 | of order 10 | 8.8855 | 2.022 | |||
| 10 | Gyroelongated square pyramid | 9 | 20 | 13 | of order 8 | 6.1962 | 1.1927 | |||
| 11 | Gyroelongated pentagonal pyramid (diminished icosahedron) | 11 | 25 | 16 | of order 10 | 8.2157 | 1.8802 | |||
| 12 | Triangular bipyramid | 5 | 9 | 6 | of order 12 | 2.5981 | 0.2357 | |||
| 13 | Pentagonal bipyramid | 7 | 15 | 10 | of order 20 | 4.3301 | 0.6030 | |||
| 14 | Elongated triangular bipyramid | 8 | 15 | 9 | of order 12 | 5.5981 | 0.6687 | |||
| 15 | Elongated square bipyramid | 10 | 20 | 12 | of order 16 | 7.4641 | 1.4714 | |||
| 16 | Elongated pentagonal bipyramid | 12 | 25 | 15 | of order 20 | 9.3301 | 2.3235 | |||
| 17 | Gyroelongated square bipyramid | 10 | 24 | 16 | of order 16 | 6.9282 | 1.4284 | |||
| 18 | Elongated triangular cupola | 15 | 27 | 14 | of order 6 | 13.3301 | 3.7766 | |||
| 19 | Elongated square cupola | 20 | 36 | 18 | of order 8 | 19.5605 | 6.7712 | |||
| 20 | Elongated pentagonal cupola | 25 | 45 | 22 | of order 10 | 26.5798 | 10.0183 | |||
| 21 | Elongated pentagonal rotunda | 30 | 55 | 27 | of order 10 | 32.3472 | 14.612 | |||
| 22 | Gyroelongated triangular cupola | 15 | 33 | 20 | of order 6 | 12.5263 | 3.5161 | |||
| 23 | Gyroelongated square cupola | 20 | 44 | 26 | of order 8 | 18.4887 | 6.2108 | |||
| 24 | Gyroelongated pentagonal cupola | 25 | 55 | 32 | of order 10 | 25.2400 | 9.0733 | |||
| 25 | Gyroelongated pentagonal rotunda | 30 | 65 | 37 | of order 10 | 31.0075 | 13.6671 | |||
| 26 | Gyrobifastigium | 8 | 14 | 8 | of order 8 | 5.7321 | 0.8660 | |||
| 27 | Triangular orthobicupola | 12 | 24 | 14 | of order 12 | 9.4641 | 2.3570 | |||
| 28 | Square orthobicupola | 16 | 32 | 18 | of order 16 | 13.4641 | 3.8856 | |||
| 29 | Square gyrobicupola | 16 | 32 | 18 | of order 16 | |||||
| 30 | Pentagonal orthobicupola | 20 | 40 | 22 | of order 20 | 17.7711 | 4.6481 | |||
| 31 | Pentagonal gyrobicupola | 20 | 40 | 22 | of order 20 | |||||
| 32 | Pentagonal orthocupolarotunda | 25 | 50 | 27 | of order 10 | 23.5385 | 9.2418 | |||
| 33 | Pentagonal gyrocupolarotunda | 25 | 50 | 27 | of order 10 | 23.5385 | ||||
| 34 | Pentagonal orthobirotunda | 30 | 60 | 32 | of order 20 | 29.306 | 13.8355 | |||
| 35 | Elongated triangular orthobicupola | 18 | 36 | 20 | of order 12 | 15.4641 | 4.9551 | |||
| 36 | Elongated triangular gyrobicupola | 18 | 36 | 20 | of order 12 | |||||
| 37 | Elongated square gyrobicupola | 24 | 48 | 26 | of order 16 | 21.4641 | 8.714 | |||
| 38 | Elongated pentagonal orthobicupola | 30 | 60 | 32 | of order 20 | 27.7711 | 12.3423 | |||
| 39 | Elongated pentagonal gyrobicupola | 30 | 60 | 32 | of order 20 | |||||
| 40 | Elongated pentagonal orthocupolarotunda | 35 | 70 | 37 | of order 10 | 33.5385 | 16.936 | |||
| 41 | Elongated pentagonal gyrocupolarotunda | 35 | 70 | 37 | of order 10 | |||||
| 42 | Elongated pentagonal orthobirotunda | 40 | 80 | 42 | of order 20 | 39.306 | 21.5297 | |||
| 43 | Elongated pentagonal gyrobirotunda | 40 | 80 | 42 | of order 20 | |||||
| 44 | Gyroelongated triangular bicupola | 18 | 42 | 26 | of order 6 | 14.6603 | 4.6946 | |||
| 45 | Gyroelongated square bicupola | 24 | 56 | 34 | of order 8 | 20.3923 | 8.1536 | |||
| 46 | Gyroelongated pentagonal bicupola | 30 | 70 | 42 | of order 10 | 26.4313 | 11.3974 | |||
| 47 | Gyroelongated pentagonal cupolarotunda | 35 | 80 | 47 | of order 5 | 32.1988 | 15.9911 | |||
| 48 | Gyroelongated pentagonal birotunda | 40 | 90 | 52 | of order 10 | 37.9662 | 20.5848 | |||
| 49 | Augmented triangular prism | 7 | 13 | 8 | of order 4 | 4.5981 | 0.6687 | |||
| 50 | Biaugmented triangular prism | 8 | 17 | 11 | of order 4 | 5.3301 | 0.9044 | |||
| 51 | Triaugmented triangular prism | 9 | 21 | 14 | of order 12 | 6.0622 | 1.1401 | |||
| 52 | Augmented pentagonal prism | 11 | 19 | 10 | of order 4 | 9.173 | 1.9562 | |||
| 53 | Biaugmented pentagonal prism | 12 | 23 | 13 | of order 4 | 9.9051 | 2.1919 | |||
| 54 | Augmented hexagonal prism | 13 | 22 | 11 | of order 4 | 11.9282 | 2.8338 | |||
| 55 | Parabiaugmented hexagonal prism | 14 | 26 | 14 | of order 8 | 12.6603 | 3.0695 | |||
| 56 | Metabiaugmented hexagonal prism | 14 | 26 | 14 | of order 4 | |||||
| 57 | Triaugmented hexagonal prism | 15 | 30 | 17 | of order 12 | 13.3923 | 3.3052 | |||
| 58 | Augmented dodecahedron | 21 | 35 | 16 | of order 10 | 21.0903 | 7.9646 | |||
| 59 | Parabiaugmented dodecahedron | 22 | 40 | 20 | of order 20 | 21.5349 | 8.2661 | |||
| 60 | Metabiaugmented dodecahedron | 22 | 40 | 20 | of order 4 | |||||
| 61 | Triaugmented dodecahedron | 23 | 45 | 24 | of order 6 | 21.9795 | 8.5676 | |||
| 62 | Metabidiminished icosahedron | 10 | 20 | 12 | of order 4 | 7.7711 | 1.5787 | |||
| 63 | Tridiminished icosahedron | 9 | 15 | 8 | of order 6 | 7.3265 | 1.2772 | |||
| 64 | Augmented tridiminished icosahedron | 10 | 18 | 10 | of order 6 | 8.1925 | 1.3950 | |||
| 65 | Augmented truncated tetrahedron | 15 | 27 | 14 | of order 6 | 14.2583 | 3.8891 | |||
| 66 | Augmented truncated cube | 28 | 48 | 22 | of order 8 | 34.3383 | 15.5425 | |||
| 67 | Biaugmented truncated cube | 32 | 60 | 30 | of order 16 | 36.2419 | 17.4853 | |||
| 68 | Augmented truncated dodecahedron | 65 | 105 | 42 | of order 10 | 102.1821 | 87.3637 | |||
| 69 | Parabiaugmented truncated dodecahedron | 70 | 120 | 52 | of order 20 | 103.3734 | 89.6878 | |||
| 70 | Metabiaugmented truncated dodecahedron | 70 | 120 | 52 | of order 4 | |||||
| 71 | Triaugmented truncated dodecahedron | 75 | 135 | 62 | of order 6 | 104.5648 | 92.0118 | |||
| 72 | Gyrate rhombicosidodecahedron | 60 | 120 | 62 | of order 10 | 59.306 | 41.6153 | |||
| 73 | Parabigyrate rhombicosidodecahedron | 60 | 120 | 62 | of order 20 | |||||
| 74 | Metabigyrate rhombicosidodecahedron | 60 | 120 | 62 | of order 4 | |||||
| 75 | Trigyrate rhombicosidodecahedron | 60 | 120 | 62 | of order 6 | |||||
| 76 | Diminished rhombicosidodecahedron | 55 | 105 | 52 | of order 10 | 58.1147 | 39.2913 | |||
| 77 | Paragyrate diminished rhombicosidodecahedron | 55 | 105 | 52 | of order 10 | |||||
| 78 | Metagyrate diminished rhombicosidodecahedron | 55 | 105 | 52 | of order 2 | |||||
| 79 | Bigyrate diminished rhombicosidodecahedron | 55 | 105 | 52 | of order 2 | |||||
| 80 | Parabidiminished rhombicosidodecahedron | 50 | 90 | 42 | of order 20 | 56.9233 | 36.9672 | |||
| 81 | Metabidiminished rhombicosidodecahedron | 50 | 90 | 42 | of order 4 | |||||
| 82 | Gyrate bidiminished rhombicosidodecahedron | 50 | 90 | 42 | of order 2 | |||||
| 83 | Tridiminished rhombicosidodecahedron | 45 | 75 | 32 | of order 6 | 55.732 | 34.6432 | |||
| 84 | Snub disphenoid | 8 | 18 | 12 | of order 8 | 5.1962 | 0.8595 | |||
| 85 | Snub square antiprism | 16 | 40 | 26 | of order 16 | 12.3923 | 3.6012 | |||
| 86 | Sphenocorona | 10 | 22 | 14 | of order 4 | 7.1962 | 1.5154 | |||
| 87 | Augmented sphenocorona | 11 | 26 | 17 | of order 2 | 7.9282 | 1.7511 | |||
| 88 | Sphenomegacorona | 12 | 28 | 18 | of order 4 | 8.9282 | 1.9481 | |||
| 89 | Hebesphenomegacorona | 14 | 33 | 21 | of order 4 | 10.7942 | 2.9129 | |||
| 90 | Disphenocingulum | 16 | 38 | 24 | of order 8 | 12.6603 | 3.7776 | |||
| 91 | Bilunabirotunda | 14 | 26 | 14 | of order 8 | 12.346 | 3.0937 | |||
| 92 | Triangular hebesphenorotunda | 18 | 36 | 20 | of order 6 | 16.3887 | 5.1087 |