The optical properties of mineral dust aerosols are very important to the radiative transfer simulations and necessary to remote sensing applications. Dust properties vary from geographic locations, dust sources and chemical and physical transformation during the transport in the atmosphere. Since the bulk optical properties of dust dependent largely on the chemical components, we compiled observation data sets to derive the effective refractive indices of Saharan dust and Asian dust. In this study, we considered the individual mineral components as an external mixture so that the Maxwell Garnett approximation and the Bruggeman approximation can be used to derive the effective refractive indices. Using the results, we also calculated the single-scattering properties, such as phase matrix, single-scattering albedo and asymmetry factor.