The structure of red mud deposits of Seydisehir, Turkey were investigated by simple but effective statistical analysis. The results obtained under variable iron oxide contents were used to generate an empirical relationship by plotting, at different scales, D-1/D-2, versus K-1/K-2, where D-1 is the percent iron oxide, D-2 is the mean percent iron oxide, K-1 is the percent silicon dioxide and K-2 is the mean percent silicon dioxide. As a result of these trials, it was found that the use of logarithmic coordinates gave a straight line with the empirical equation for the system in question being: D-1 = 1.0092 . D-2 K-1(0.02) . K-2(-0.02). (C) 1998 Elsevier Science B.V.