In order to ascertain the metastable phase relation in the Cr2O3-Fe2O3 system, the existing phases were investigated by X-ray analysis using samples obtained by heating the coprecipitated powders for 1 h at 600-1000 degreesC. There was a metastable two-phase region of Cr2O3-rich (CC) and Fe2O3-rich (FC) phases below about 940 degreesC. Equilibrium state of 1:1 composition at 600-900 degreesC was considered to be a single phase of the corundum solid solution. The metastable two-phase CC + FC region was suggested to appear probably due to the compositional inhomogeneity in the coprecipitated powders. (C) 2003 Kluwer Academic Publishers.