Trapezohedron

noun

1. Any of several forms of crystal with trapeziums as faces.
2. In crystallography, a solid belonging to the isometric system, bounded by twenty-four equal and similar trapezoidal planes; a tetragonal trisoctahedron.
3. Any solid having trapezoidal faces, as the trigonal trapezohedron of a quartz crystal. See tetartohedrism. Also trapezihedron.
4. A solid bounded by twenty-four equal and similar trapeziums; a tetragonal trisoctahedron. See the Note under trisoctahedron.
5. A tetartohedral solid of the hexagonal system, bounded by six trapezoidal planes. The faces of this form are common on quartz crystals.