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:
- 48 composed of the primitive pyramids, cupolas, and rotundas assembled in various ways together with prisms and antiprisms;
- 35 formed by modifying uniform polyhedra, by augmenting, diminishing, or gyrating with primitives; and
- 9 which are not derived from "cut-and-paste" manipulations of uniform solids.
Definition and background


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.
A convex polyhedron in which all faces are nearly regular, but some are not precisely regular, is known as a near-miss Johnson solid.
Naming and construction of solids

- 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.
Pyramids, cupolas, rotundas
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:
- Bi- indicates that two copies of the solid are joined base-to-base.
- For cupolas and rotundas, ortho- indicates that like faces meet.
- For cupolas and rotundas, gyro- indicates that unlike faces meet.
- Elongated indicates a prism is joined to the base of the solid, or between the bases.
- Gyroelongated indicates an antiprism is joined to the base of the solid, or between the bases.
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 |
Modified uniform polyhedra
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:
- Augmented indicates a pyramid or cupola is added to one or more faces of the solid in question.
- Diminished indicates a pyramid or cupola is removed from one or more faces of the solid in question.
- Gyrate indicates a cupola mounted on or featured in the solid in question is rotated such that different edges match up.
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.
Non cut-and-paste
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:
- A lune is a figure of two triangles attached to opposite sides of a square. Prefixes indicating a complex of lunes are:
- Spheno- is a wedgelike complex of two adjacent lunes. Dispheno- indicates two such complexes.
- Hebespheno- is a blunt complex of three adjacent lunes.
- Suffixes indicating a complex of triangles are:
- -corona is a crownlike complex of eight triangles.
- -megacorona is a larger crownlike complex of twelve triangles.
- -cingulum is a belt of twelve triangles.
- Suffix -rotunda indicates a complex of two or three pentagons with triangles between them, bearing a structural resemblance to the pentagonal rotunda.
| 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 |
Notable subsets
Deltahedra
Five Johnson solids are deltahedra, with only triangle faces.
- J12 Triangular bipyramid
- J13 Pentagonal bipyramid
- J17 Gyroelongated square bipyramid
- J51 Triaugmented triangular prism
- J84 Snub disphenoid
Elementary 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:
- J1 square pyramid
- J2 pentagonal pyramid
- J3 triangular cupola
- J4 square cupola
- J5 pentagonal cupola
- J6 pentagonal rotunda
The criterion is also satisfied by eleven other Johnson solids:
- J63 tridiminished icosahedron
- J80 parabidiminished rhombicosidodecahedron
- J83 tridiminished rhombicosidodecahedron
- J84 snub disphenoid
- J85 snub square antiprism
- J86 sphenocorona
- J88 sphenomegacorona
- J89 hebesphenomegacorona
- J90 disphenocingulum
- J91 bilunabirotunda
- J92 triangular hebesphenorotunda
Chiral solids
The five gyroelongated bicupolas or birotundas are chiral and have distinct left-handed and right-handed forms.
- J44 Gyroelongated triangular bicupola
- J45 Gyroelongated square bicupola
- J46 Gyroelongated pentagonal bicupola
- J47 Gyroelongated pentagonal cupolarotunda
- J48 Gyroelongated pentagonal birotunda
Circumscribable solids
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.
Characteristics of solids
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 | 2.7321 | 0.2357 | ||||
| 2 | Pentagonal pyramid | 6 | 10 | 6 | 3.8855 | 0.3015 | ||||
| 3 | Triangular cupola | 9 | 15 | 8 | 7.3301 | 1.1785 | ||||
| 4 | Square cupola | 12 | 20 | 10 | 11.5605 | 1.9428 | ||||
| 5 | Pentagonal cupola | 15 | 25 | 12 | 16.5798 | 2.3241 | ||||
| 6 | Pentagonal rotunda | 20 | 35 | 17 | 22.3472 | 6.9178 | ||||
| 7 | Elongated triangular pyramid | 7 | 12 | 7 | 4.7321 | 0.5509 | ||||
| 8 | Elongated square pyramid | 9 | 16 | 9 | 6.7321 | 1.2357 | ||||
| 9 | Elongated pentagonal pyramid | 11 | 20 | 11 | 8.8855 | 2.022 | ||||
| 10 | Gyroelongated square pyramid | 9 | 20 | 13 | 6.1962 | 1.1927 | ||||
| 11 | Gyroelongated pentagonal pyramid (diminished icosahedron) | 11 | 25 | 16 | 8.2157 | 1.8802 | ||||
| 12 | Triangular bipyramid | 5 | 9 | 6 | 2.5981 | 0.2357 | ||||
| 13 | Pentagonal bipyramid | 7 | 15 | 10 | 4.3301 | 0.6030 | ||||
| 14 | Elongated triangular bipyramid | 8 | 15 | 9 | 5.5981 | 0.6687 | ||||
| 15 | Elongated square bipyramid | 10 | 20 | 12 | 7.4641 | 1.4714 | ||||
| 16 | Elongated pentagonal bipyramid | 12 | 25 | 15 | 9.3301 | 2.3235 | ||||
| 17 | Gyroelongated square bipyramid | 10 | 24 | 16 | 6.9282 | 1.4284 | ||||
| 18 | Elongated triangular cupola | 15 | 27 | 14 | 13.3301 | 3.7766 | ||||
| 19 | Elongated square cupola | 20 | 36 | 18 | 19.5605 | 6.7712 | ||||
| 20 | Elongated pentagonal cupola | 25 | 45 | 22 | 26.5798 | 10.0183 | ||||
| 21 | Elongated pentagonal rotunda | 30 | 55 | 27 | 32.3472 | 14.612 | ||||
| 22 | Gyroelongated triangular cupola | 15 | 33 | 20 | 12.5263 | 3.5161 | ||||
| 23 | Gyroelongated square cupola | 20 | 44 | 26 | 18.4887 | 6.2108 | ||||
| 24 | Gyroelongated pentagonal cupola | 25 | 55 | 32 | 25.2400 | 9.0733 | ||||
| 25 | Gyroelongated pentagonal rotunda | 30 | 65 | 37 | 31.0075 | 13.6671 | ||||
| 26 | Gyrobifastigium | 8 | 14 | 8 | 5.7321 | 0.8660 | ||||
| 27 | Triangular orthobicupola | 12 | 24 | 14 | 9.4641 | 2.3570 | ||||
| 28 | Square orthobicupola | 16 | 32 | 18 | 13.4641 | 3.8856 | ||||
| 29 | Square gyrobicupola | 16 | 32 | 18 | ||||||
| 30 | Pentagonal orthobicupola | 20 | 40 | 22 | 17.7711 | 4.6481 | ||||
| 31 | Pentagonal gyrobicupola | 20 | 40 | 22 | ||||||
| 32 | Pentagonal orthocupolarotunda | 25 | 50 | 27 | 23.5385 | 9.2418 | ||||
| 33 | Pentagonal gyrocupolarotunda | 25 | 50 | 27 | 23.5385 | |||||
| 34 | Pentagonal orthobirotunda | 30 | 60 | 32 | 29.306 | 13.8355 | ||||
| 35 | Elongated triangular orthobicupola | 18 | 36 | 20 | 15.4641 | 4.9551 | ||||
| 36 | Elongated triangular gyrobicupola | 18 | 36 | 20 | ||||||
| 37 | Elongated square gyrobicupola | 24 | 48 | 26 | 21.4641 | 8.714 | ||||
| 38 | Elongated pentagonal orthobicupola | 30 | 60 | 32 | 27.7711 | 12.3423 | ||||
| 39 | Elongated pentagonal gyrobicupola | 30 | 60 | 32 | ||||||
| 40 | Elongated pentagonal orthocupolarotunda | 35 | 70 | 37 | 33.5385 | 16.936 | ||||
| 41 | Elongated pentagonal gyrocupolarotunda | 35 | 70 | 37 | ||||||
| 42 | Elongated pentagonal orthobirotunda | 40 | 80 | 42 | 39.306 | 21.5297 | ||||
| 43 | Elongated pentagonal gyrobirotunda | 40 | 80 | 42 | ||||||
| 44 | Gyroelongated triangular bicupola | 18 | 42 | 26 | 14.6603 | 4.6946 | ||||
| 45 | Gyroelongated square bicupola | 24 | 56 | 34 | 20.3923 | 8.1536 | ||||
| 46 | Gyroelongated pentagonal bicupola | 30 | 70 | 42 | 26.4313 | 11.3974 | ||||
| 47 | Gyroelongated pentagonal cupolarotunda | 35 | 80 | 47 | 32.1988 | 15.9911 | ||||
| 48 | Gyroelongated pentagonal birotunda | 40 | 90 | 52 | 37.9662 | 20.5848 | ||||
| 49 | Augmented triangular prism | 7 | 13 | 8 | 4.5981 | 0.6687 | ||||
| 50 | Biaugmented triangular prism | 8 | 17 | 11 | 5.3301 | 0.9044 | ||||
| 51 | Triaugmented triangular prism | 9 | 21 | 14 | 6.0622 | 1.1401 | ||||
| 52 | Augmented pentagonal prism | 11 | 19 | 10 | 9.173 | 1.9562 | ||||
| 53 | Biaugmented pentagonal prism | 12 | 23 | 13 | 9.9051 | 2.1919 | ||||
| 54 | Augmented hexagonal prism | 13 | 22 | 11 | 11.9282 | 2.8338 | ||||
| 55 | Parabiaugmented hexagonal prism | 14 | 26 | 14 | 12.6603 | 3.0695 | ||||
| 56 | Metabiaugmented hexagonal prism | 14 | 26 | 14 | ||||||
| 57 | Triaugmented hexagonal prism | 15 | 30 | 17 | 13.3923 | 3.3052 | ||||
| 58 | Augmented dodecahedron | 21 | 35 | 16 | 21.0903 | 7.9646 | ||||
| 59 | Parabiaugmented dodecahedron | 22 | 40 | 20 | 21.5349 | 8.2661 | ||||
| 60 | Metabiaugmented dodecahedron | 22 | 40 | 20 | ||||||
| 61 | Triaugmented dodecahedron | 23 | 45 | 24 | 21.9795 | 8.5676 | ||||
| 62 | Metabidiminished icosahedron | 10 | 20 | 12 | 7.7711 | 1.5787 | ||||
| 63 | Tridiminished icosahedron | 9 | 15 | 8 | 7.3265 | 1.2772 | ||||
| 64 | Augmented tridiminished icosahedron | 10 | 18 | 10 | 8.1925 | 1.3950 | ||||
| 65 | Augmented truncated tetrahedron | 15 | 27 | 14 | 14.2583 | 3.8891 | ||||
| 66 | Augmented truncated cube | 28 | 48 | 22 | 34.3383 | 15.5425 | ||||
| 67 | Biaugmented truncated cube | 32 | 60 | 30 | 36.2419 | 17.4853 | ||||
| 68 | Augmented truncated dodecahedron | 65 | 105 | 42 | 102.1821 | 87.3637 | ||||
| 69 | Parabiaugmented truncated dodecahedron | 70 | 120 | 52 | 103.3734 | 89.6878 | ||||
| 70 | Metabiaugmented truncated dodecahedron | 70 | 120 | 52 | ||||||
| 71 | Triaugmented truncated dodecahedron | 75 | 135 | 62 | 104.5648 | 92.0118 | ||||
| 72 | Gyrate rhombicosidodecahedron | 60 | 120 | 62 | 59.306 | 41.6153 | ||||
| 73 | Parabigyrate rhombicosidodecahedron | 60 | 120 | 62 | ||||||
| 74 | Metabigyrate rhombicosidodecahedron | 60 | 120 | 62 | ||||||
| 75 | Trigyrate rhombicosidodecahedron | 60 | 120 | 62 | ||||||
| 76 | Diminished rhombicosidodecahedron | 55 | 105 | 52 | 58.1147 | 39.2913 | ||||
| 77 | Paragyrate diminished rhombicosidodecahedron | 55 | 105 | 52 | ||||||
| 78 | Metagyrate diminished rhombicosidodecahedron | 55 | 105 | 52 | ||||||
| 79 | Bigyrate diminished rhombicosidodecahedron | 55 | 105 | 52 | ||||||
| 80 | Parabidiminished rhombicosidodecahedron | 50 | 90 | 42 | 56.9233 | 36.9672 | ||||
| 81 | Metabidiminished rhombicosidodecahedron | 50 | 90 | 42 | ||||||
| 82 | Gyrate bidiminished rhombicosidodecahedron | 50 | 90 | 42 | ||||||
| 83 | Tridiminished rhombicosidodecahedron | 45 | 75 | 32 | 55.732 | 34.6432 | ||||
| 84 | Snub disphenoid | 8 | 18 | 12 | 5.1962 | 0.8595 | ||||
| 85 | Snub square antiprism | 16 | 40 | 26 | 12.3923 | 3.6012 | ||||
| 86 | Sphenocorona | 10 | 22 | 14 | 7.1962 | 1.5154 | ||||
| 87 | Augmented sphenocorona | 11 | 26 | 17 | 7.9282 | 1.7511 | ||||
| 88 | Sphenomegacorona | 12 | 28 | 18 | 8.9282 | 1.9481 | ||||
| 89 | Hebesphenomegacorona | 14 | 33 | 21 | 10.7942 | 2.9129 | ||||
| 90 | Disphenocingulum | 16 | 38 | 24 | 12.6603 | 3.7776 | ||||
| 91 | Bilunabirotunda | 14 | 26 | 14 | 12.346 | 3.0937 | ||||
| 92 | Triangular hebesphenorotunda | 18 | 36 | 20 | 16.3887 | 5.1087 |
