What does "octahedral" mean?

Octahedral: Having eight faces or sides; of, pertaining to, or formed in, octahedrons; as, octahedral cleavage. Octahedral borax (Chem.), borax obtained from a saturated solution in octahedral crystals, which contain five molecules of water of crystallization; distinguished from common or prismatic borax. -- Octahedral iron ore (Min.), magnetite.