The cube is also a square parallelepiped, an equilateral cuboid and a right rhombohedron. A parallelepiped can be considered as an oblique prism with a parallelogram as base. The three-dimensional counterpart of a parallelogram is a parallelepiped. A tetrahedron is a disphenoid if and only if its circumscribed parallelepiped is right-angled. A parallelepiped is a three-dimensional figure whose six faces are parallelograms. A tetrahedron is orthocentric if and only if its circumscribed parallelepiped is a rhombohedron. Thus the faces of a parallelepiped are planar, with opposite faces being parallel. All tetrahedra can be inscribed in a parallelepiped. A "perfect parallelepiped" is a parallelepiped with integer-length edges, face diagonals, and space diagonals. A space-filling tessellation is possible with congruent copies of any parallelepiped. Also the whole parallelepiped has point symmetry "C" (see also triclinic). Since each face has point symmetry, a parallelepiped is a zonohedron. More generally, the Dehn invariant of any parallelepiped is also zero. The principal building material is coral, sawn to approximately parallelepiped shape and dressed like stone.