It has been found that various refractory oxides can be crystallized from molten PbO&sngbnd;PbF2and Bi2O3&sngbnd;BiF3solutions. The PbO&sngbnd;PbF2solvent has proved successful for the growth of high alumina compounds including aluminum garnets, rare‐earth orthoaluminates, spinels, magnetoplumbite‐type aluminates, aluminum oxide, and the divalent oxides BeO and MnO. The Bi2O3&sngbnd;BiF3system has proven successful for the growth of the ferrite GaFeO3. The stability ranges of these various compounds is discussed in addition to problems of doping and attainment of large single crystals.