Using a detailed configuration accounting model with term structures treated by the unresolved transition array model, we have extensively investigated the opacities of mixt ure materials. For plasmas at the temperat ure of 250eV and density of 1 g/cm3, our calculated Rosseland mean opacities are in good agreement with other theoretical results. A high increase in the Rosseland mean opacity to 2944 cm2/g is achieved for a multi-element mixture compared to the value of 1729 cm2/g for pure gold. Various mixtures at other plasma conditions are also studied.