Calcium chromates with the empirical formulas Ca10Cr6O25, Ca3Cr2O8, and Ca5Cr4O12, which form at temperatures >900 degrees C at CaO:Cr2O3 molar ratios of greater than or equal to 3 in an oxidation atmosphere have been synthesized in the pure state. X-ray absorption near-edge structure (XANES) spectroscopy has been used to determine the average valence state of chromium in the samples. The presence of unusual chromium valence states, 4+ and 5+, which was proposed via X-ray diffractometry studies, is strongly supported.