Dacite consists mostly of plagioclase feldspar with biotite, hornblende, and pyroxene (augite and/or enstatite). Phenocryst phases include amphibole, biotite, plagioclase, pyroxene and titanomagnetite. The mineral assemblage is typically dominated by plagioclase plus pyroxene or hornblende. The mineralogy of basalt is characterized by a preponderance of calcic plagioclase feldspar and pyroxene. OC meteorites contain varying amounts of the silicates olivine and pyroxene, iron, and feldspar. The andesite rock contains some visible crystals of pyroxene or amphibole. Chloritization is the alteration of pyroxene or amphibole minerals into the chlorite group minerals. Fine grained sedimentary rocks were transformed into hornfels and minerals such as amphibole, pyroxene. With prograde metamorphism cummingtonite and grunerite morph to members of the olivine and pyroxene series. The upper mantle of Earth is composed mainly of olivine and pyroxene. Both pyroxene and olivine, common asteroid minerals, can hydrate in this manner. The volcanoes consist mostly of pyroxene andesite. Diopside is a monoclinic pyroxene mineral with composition MgCaSiO. The researchers found concentrations of olivine and pyroxene in the "Hayabusa" samples. Shastina has been built by mostly pyroxene andesite lava flows.