Rocks erupted from Sollipulli range from basalt over basaltic andesite and andesite to dacite. Composition has changed over the evolution of the volcano; sometimes one type of rock is found as inclusion in another. Minerals contained in the rocks include apatite, clinopyroxene, ilmenite, olivine, orthopyroxene, plagioclase and titanomagnetite. Xenoliths are also found, including diorite and granophyre.