, the  rhombic dodecahedron  is a  convex   polyhedron with 12  rhombic  faces. It is an  Archimedean dual  solid, or a  Catalan solid . Its  dual  is the  cuboctahedron . The rhombic dodecahedron is a zonohedron . Its polyhedral  dual  is the cuboctahedron . The long diagonal of each face is