Indeed at first look, good crystals of hausmannite appear to be octahedrons like those formed by the spinel group of minerals. However, those A and B positions are filled with other elements when either one has a manganese ion present. Both sites can not accommodate a manganese ion at the same time and still preserve the isometric structure. Ergo, hausmannite has a distorted spinel structure that produces a tetragonal symmetry and a basal cleavage not possible in the spinel group of minerals. At much higher temperatures, the structure of hausmannite converts to the isometric spinel structure.
Color is dark brown or black.
Luster is submetallic to metallic. Minor pyramidal faces may truncate only the top and bottom points, giving evidence of its tetragonal symmetry instead of the isometric octahedron. Twinning is common and repeated. Also granular and massive. Cleavage is perfect in one direction, basal.