We describe the syntheses, crystal structures, and optical absorption studies of the transition-metal-substituted corundum-related oxides (MM′) 3 TeO 6 (M = Mg, Mn, Co, Ni, Zn; M′ = Mg, Mn, Co, Ni, Cu). The oxides are readily synthesized by the solid-state reactions of stoichiometric mixtures of the constituent binaries at 750-860°C. The Rietveld refinements of the crystal structures from the powder X-ray diffraction (XRD) data show that the Mg/Mn/Ni/Co/ZnO 6 octahedra are distorted. We have interpreted the unique colors and the optical absorption spectra of these materials in terms of the distorted coordi- [a]