Earth and Atmosphere GEOL 83 – Rock and Mineral Identification Minerals Quartz Calcite Plagioclase (Feldspar) Orthoclase (Feldspar) Biotite Muscovite Hornblende (Amphibole) Talc Pyrite Gypsum Graphite Magnetite Hematite Olivine Galena Chalcopyrite Halite (Common salt) Pyroxene Rocks Conglomerate Schist (Granet) Amphibolite Hornfels Marble Shale Gneiss Limestone (Fossiliferous) Slate Quartzite Rhyolite Andesite Diorite Gabbro Limestone Sandstone Granite Basalt