The kinetic stabilization of metastable rs-ZnO at ambient pressure can be achieved by quenching of microcrystalline ZnO-based solid solutions with a relatively high (up to 80 mol%) ZnO content from high pressure and high temperature. Recently, metastable rs-Me 1-x Zn x O (Me = Mg 2+ , Ni 2+ , Co 2+ , Fe 2+ , Mn 2+ ) solid solutions have been successfully synthesized by quenching from 4.6-7.7