The densities of a molten mixture of (0.5 AgI + 0.5 NaCl) were measured along the saturation line over a wide temperature range by the hydrostatic weight method to establish the peculiarities of the mixing of salts with different chemical bonds. We showed that the difference between the magnitudes of the densities for the coexisting phases decreases with increasing temperature and becomes equal to zero at 1063.5 K. This temperature corresponds to the critical phase transition point, T-c. The temperature dependence of the difference in densities, Delta rho, is described by equation Delta rho/rho(c) approximate to (T-c-T/T-c)(beta), where rho(c) is the density at T-c. The index beta = 0.476 occurs at a lower value than that found for alkali halide melts (beta = 0.52) where long-range Coulombic forces between ions prevail. (C) 2013 Elsevier Ltd. All rights reserved.