Novel aluminum-silicate based orange-red phosphors, with mixed di- and trivalent cations are disclosed. The phosphors have the formula (Sr1−x−yMxTy)3−mEum(Si1−zAlz)O5, where M is at least one of Ba, Mg, Ca, and Zn in an amount ranging from 0≦x≦0.4. T is a trivalent metal in an amount ranging from 0≦y≦0. This phosphor is configured to emit visible light having a peak emission wavelength greater than about 580 nm. The phosphors may contain a halogen anion such as F, Cl, and Br, at least some of which is substitutionally positioned on oxygen lattice sites. The present aluminum-silicate phosphors have applications in white and orange-red illumination systems, as well as plasma display panels.