A coating including a bond layer deposited on a substrate. The bond layer includes a rare earth silicate and a second phase, the second phase including at least one of silicon, silicides, alkali metal oxides, alkali earth metal oxides, glass ceramics, Al2O3, TiO2, Ta2O5, HfO2, ZrO2, HfSiO4, ZrSiO4, HfTiO4, ZrTiO4, or mullite. The coating may provide thermal and/or environmental protection for the substrate, especially when the substrate is a component of a high-temperature mechanical system.