This paper presents a new class of binary compounds with quartz topology using boron nitride and silicon carbide as examples. The structures of qtz BN and qtz SiC have been constructed from the template carbon allotrope C 6 with quartz topology. It has been shown that the new phases are the densest among all known BN and SiC polymorphs. Accordingly, they are characterized by the highest hardness. In addition to mechanical stability, the new phases are also dynamically stable as indicated by the phonon band structures. The heat capacities of the new phases calculated from the phonon frequencies were found to be higher than those of the corresponding cubic phases; this is also true for qtz C 6 compared to diamond. It can be assumed that all of the above is a consequence of the presence of distorted tetrahedra in the crystal structures of the phases with quartz topology. Finally, from the analysis of electronic band structures and densities of states, it was found that the new phases exhibit semiconducting behavior.