Great spinoretrosnub heptishexacosichoron

The great spinoretrosnub heptishexacosichoron, or gnarshex, is a nonconvex uniform polychoron that consists of 600 great icosahedra and 600 small stellated dodecahedra (falling into pairs in the same hyperplanes, forming 600 compounds of one of each), 600 icosahedra and 600 great dodecahedra (forming 600 compounds of one of each), 2400 octahemioctahedra and 2400 cubohemioctahedra (forming 2400 compounds of one of each), 600 cuboctahedra (forming 120 antirhombicosicosahedra), 1200 great dodecicosahedra (forming 600 compounds of two), and 600 rhombidodecadodecahedra.

One great icosahedron and one small stellated dodecahedron (two compounds), one icosahedron and one great dodecahedron (two compounds), four octahemioctahedra and four cubohemioctahedra (eight compounds), one cuboctahedron (one compound), ten great dodecicosahedra (ten compounds), and five rhombidodecadodecahedra join at each vertex.

It can be obtained as the blend of 5 great dipentary dishecatonicosihexacosihecatonicosachora and 5 great capped dipentary tetrishecatonicosihexacosichora. In the process, some of the octahemioctahedron and cubohemioctahedron cells blend out.

Vertex coordinates
Its vertices are the same as those of its regiment colonel, the great diretrosnub disnub decahecatonicosadishexacosichoron.