Applying the stellation process to a regular icosahedron gives
cells of 10 different shapes and sizes (Wenninger 1989, p. 41).
After application of five restrictions known as Miller's rules to define which forms should be considered significant and distinct (Coxeter et al. 1999, pp. 15-16), 59 stellations (including the original regular icosahedron itself) are possible (Coxeter et al. 1999). These stellations are illustrated above are given in the original ordering of Maeder (1994).
18 of the 59 stellations are fully supported. Of these, 16 are reflexible and 2 are chiral (Webb).
Of the 59 icosahedron stellations, 32 have full icosahedral symmetry and 27 are enantiomeric forms (Coxeter et al. 1999, pp. 64-65). One is a Platonic solid (the icosahedron itself), one is a Kepler-Poinsot polyhedron, four are polyhedron compounds, and one is the dual polyhedron of an Archimedean solid. Note that the first real stellation (stellation #2 in Coxeter's counting) is that obtained by cumulating the icosahedron until the faces of each triangular pyramid lie parallel to the surrounding original faces. This gives fairly small spikes, and results in a solid known as the small triambic icosahedron. Note also that the great stellated dodecahedron is not an icosahedron stellation since the faces of its groups of five triangular pyramids do not lie in the same plane (even though they appear very close to it).
The original icosahedron, its 20 facial planes, and the intersections of those planes with the facial plane of the "top" face are illustrated above.
The stellation diagram showing the 18 lines of intersections of one face with the 18 other nonparallel faces is shown above, together with the regions into which these intersections divide the plane (Coxeter et al. 1999, p. 17).
The numbering of the regions can be simplified by writing for both 2 and , for 4 and , for 11 and , and for all of 13, , and (Coxeter et al. 1999, pp. 18-19).
The following table (extending Coxeter et al. 1999, pp. 13 and 64-65) summarizes different orderings and notations used by a number of authors. The newer Maeder numbering ("Stellated Icosahedra" web page, "Fifty-Nine Icosahedra" Demonstration) orders by increasing circumradius . Rogers ("Playing with Stellations of the Icosahedron" Demonstration) uses the ordering and §3 notation of Coxeter et al. (1999). Stellations with Coxeter index 1-32 are amphichiral, while those with index 33-59 are chiral stellations listed in dextro form. To obtain the laevo form, change Roman to italic and vice versa in both "§2" and "§3" notations (Coxeter et al. 1999, pp. 64-65).
MathWorld name | Coxeter | Coxeter §2 | Coxeter §3 | Coxeter plate | Coxeter name | Wenninger | Wenninger name | Wheeler | Brückner | Maeder | Maeder |
regular icosahedron | 1 | I | icosahedron | 4 | 1 | 1 | 1 | ||||
small triambic icosahedron | 2 | I | triakisicosahedron | 26 | triakis icosahedron | 2 | Fig. 2, Taf. VIII | 2 | 2 | ||
octahedron 5-compound | 3 | I | five octahedra | 23 | 3 | Fig. 6, Taf. IX | 3 | 3 | |||
4 | I | 4 | Fig. 17, Taf. IX | 5 | 4 | ||||||
5 | II | 16 | 9 | ||||||||
6 | II | 27 | 2nd stellation | 19 | 21 | 35 | |||||
great icosahedron | 7 | II | great icosahedron | 41 | great icosahedron | 11 | Fig. 24, Taf. XI | 11 | 54 | ||
echidnahedron | 8 | III | complete stellation | 42 | final stellation | 12 | Fig. 14, Taf. XI | 4 | 59 | ||
9 | IV | 37 | 12th stellation | 6 | 7 | ||||||
10 | IV | 30 | 14 | ||||||||
11 | IV | 29 | 4th stellation | 21 | 10 | 24 | |||||
12 | V | 24 | 10 | ||||||||
13 | V | 20 | 26 | 20 | |||||||
14 | V | 32 | 23 | ||||||||
15 | VI | 14 | 6 | ||||||||
16 | VI | 22 | 8 | 33 | |||||||
17 | VI | 22 | 55 | ||||||||
18 | VII | 15 | 32 | ||||||||
19 | VII | 28 | 44 | ||||||||
20 | VII | 30 | 5th stellation | 19 | 45 | ||||||
21 | VIII | 32 | 7th stellation | 10 | 7 | 8 | |||||
tetrahedron 10-compound | 22 | VIII | 25 | compound of ten tetrahedra | 8 | Fig. 3, Taf. IX | 18 | 12 | |||
23 | VIII | 31 | 6th stellation | 17 | Fig. 3, Taf. X | 23 | 39 | ||||
24 | IX | 27 | 11 | ||||||||
25 | IX | 29 | 21 | ||||||||
inwardly augmented dodecahedron | 26 | IX | 9 | Fig. 26, Taf. VIII | 20 | 22 | |||||
27 | X | 28 | 3rd stellation | 5 | 12 | 5 | |||||
28 | X | 18 | Fig. 20, Taf. IX | 17 | 34 | ||||||
29 | X | 33 | 8th stellation | 14 | 9 | 47 | |||||
30 | XI | 34 | 9th stellation | 13 | 13 | 31 | |||||
31 | XI | 25 | 43 | ||||||||
32 | XI | 31 | 46 | ||||||||
33 | XII | 35 | 10th stellation | 33 | 13 | ||||||
34 | XII | 36 | 11th stellation | 34 | 15 | ||||||
35 | XII | 35 | 16 | ||||||||
36 | XIII | 39 | 25 | ||||||||
37 | XIII | 39 | 14th stellation | 45 | 26 | ||||||
38 | XIII | 47 | 27 | ||||||||
39 | XIV | 50 | 56 | ||||||||
40 | XIV | 54 | 57 | ||||||||
41 | XIV | 58 | 58 | ||||||||
42 | XV | 48 | 51 | ||||||||
43 | XV | 52 | 52 | ||||||||
44 | XV | 56 | 53 | ||||||||
45 | XVI | 40 | 15th stellation | 42 | 19 | ||||||
46 | XVI | 40 | 18 | ||||||||
tetrahedron 5-compound (dextro) | 47 | XVI | five tetrahedra | 24 | compound of five tetrahedra | 7 | 36 | 17 | |||
tetrahedron 5-compound (laevo) | 6 | Fig. 11, Taf. IX | |||||||||
48 | XVII | 57 | 30 | ||||||||
49 | XVII | 53 | 29 | ||||||||
50 | XVII | 49 | 28 | ||||||||
51 | XVIII | 38 | 13th stellation | 43 | 38 | ||||||
52 | XVIII | 41 | 37 | ||||||||
(dextro) | 53 | XVIII | 15 | 37 | 36 | ||||||
(laevo) | 16 | ||||||||||
54 | XIX | 59 | 42 | ||||||||
55 | XIX | 55 | 41 | ||||||||
56 | XIX | 51 | 40 | ||||||||
57 | XX | 46 | 50 | ||||||||
58 | XX | 44 | 49 | ||||||||
59 | XX | 38 | 48 |
Coxeter stellation number 30 () corresponds to the hull of the medial triambic icosahedron and great triambic icosahedron (Wenninger 1983, pp. 45-50).