Samples of black (Fe,Cr)2O3 pigment were prepared from a starting mixture of Fe2O3 and Cr2O3 (50:50 by weight) at five temperatures between 1273 and 1423 K, using synthesis times ranging from 0 to 9 h. The influence of synthesis temperature and time on the chromatic coordinates of the pigment samples was established, and their chromatic coordinates were determined. On the basis of the experimental results, a single empirical correlation was obtained between each of the chromatic coordinates and the mass fraction in solid solution of the same composition as the starting oxide mixture present in each pigment sample.
