Mylonite is a type of rock that is easily distinguishable by its fine-grained texture and characteristic foliation. While "mylonite" is a term commonly used to describe this unique rock, there are several synonyms that can be used to refer to the same material. Some common synonyms for mylonite include gneiss, schist, phyllite, and slate. Each of these terms describes a type of metamorphic rock that shares some of the same physical and chemical properties as mylonite. While different in appearance and composition, these rocks are all formed through the slow and steady transformation of pre-existing materials caused by intense heat and pressure.