Type of rock is a broad term that encompasses many different types of rocks. IGNEOUS rocks are formed from molten material and cooled over time. Xenoliths are pieces of rock that are found in other rocks. Glam is a type of metamorphic rock that is composed of mica and quartz. ACID rocks are those that have a high silica content. Breccia is a type of sedimentary rock that is made up of angular fragments. PUNK is a type of IGNEOUS rock that is formed from lava. Prog is a type of sedimentary rock that is composed of sandstone and shale. Shale is a type of sedimentary rock that is made up of clay and silt particles.