Refractive indices of In2O3, In2-xSnxO3, InBO3 and 2 different gahnite crystals (Zn0.95Fe0.05Al2O4 and Zn0.91Mg0.04Mn0.03Fe0.03Al1.99Fe0.01O4) were.measured at wavelengths of 435.8-643.8 nm and were used to calculate n (n(D)) at lambda = 589.3 nm and (n(infinity)) at lambda = infinity with the one-term Sellmeier equation 1/(n(2) - 1) = -A/lambda(2) + B. Total polarizabilities, alpha(total), were calculated from n(infinity) the Lorenz-Lorentz equation. Refractive indices, n(D) and dispersion values, A, are, respectively, 2.093 and 133 x 10(-16) m(2) for In2O3; 2.0755 and 138 x 10(-16) m(2) for In2-xSnxO3; 1.7995 and 56 x 10(-16) m(2) for Zn0.93Fe0.05Al2O4; 1.7940 and 57 x 10(-16) m(2) for Zn0.91Mg0.04Mn0.03Fe0.03Al1.99Fe0.01O4 and n(o) = 1.8782 and n(e) = 1.7756 and < 63 > x 10(-16) m(2) for InBO3. The lack of consistency of the polarizabilities of Zn2+ in ZnO and In3+ in In2O3 with the Zn2+ and In3+ polarizabilities in other Zn- and In-containing compounds is correlated with structural strain and very high dispersion of ZnO and In2O3. (C) 2013 Elsevier Ltd. All rights reserved.