Having eight faces or sides; of, pertaining to, or formed in, octahedrons; as, octahedral cleavage; an octahedral crystal.
cleavage Type of cleavage exhibited on minerals of the isometric system that crystallize as octahedrons. The method of cleavage is that flat, triangular "wedges" peel off of the existing octahedron. Example is Fluorite.
an eight-sided diamond crystal in which all the faces are equilateral triangles