Pentagonal Cupola (J5)
One of the 92 Johnson solids, which are non-uniform convex regular-faced
polyhedra. This one has 5-fold pyramidal symmetry, and may be thought of as one cap from a rhombicosidodecahedron.
J5 has been useful in constructing Stewart toroids, such as the
drilled pentagonal rotunda, the
drilled truncated dodecahedron, and this more
genus-41 Stewart toroid.