Phyllite is one of the important type of rocks. If we have to define Phyllite in general, Phyllite is a fine-grained metamorphic rock with a well-developed laminar structure, and is intermediate between slate and schist rocks. Phyllite comes under Metamorphic Rocks. All Metamorphic Rocks have similar properties and formation process. Along with Phyllite Definition, know more about the History of Phyllite, Etymology of Phyllite in next sections.