This polyhedron was the 91st detailed in Johnson's seminal paper, consequently it's often notated J91, the 91st . It is an elementary polyhedron that may not be formed from other basic Platonic, Archimedean, and Johnson solids. Six bilunabirotundas may be used to form the lovely Stewart's 6J91(P4), which may be utilized further to form the central 6-way hole for the fabulous Lunar-holed Rhombicosidodecahedron, Stewart's E5/6J91(P4). These models were built using Geomag Pastelles.