Facet Shapes number Sphericity S/[V.sup.2/3] Tetrahedron 4 0.67 7.21 Pentahedron I 5 0.70 6.95 Pentahedron II 5 0.72 6.71 Hexahedron 6 0.76 6.39 Cube 6 0.81 6.00
Heptahedron I 7 0.83 5.83
Heptahedron II 7 0.80 6.06 Octahedron I 8 0.85 5.72 Octahedron II 8 0.78 6.24 Sphere [infinity] 1.00 4.84
Gomez-Torrente, Mario, 2003, "The 'Must' and the '
Heptahedron'.
One such gem is Robert Starer's
Heptahedron - A Statue Having Seven Faces, a work he wrote for the legendary harpsichordist Fernando Valenti.