Mudrocks are made of >50% particles in the mud size fraction (<1/16 mm). They can be subdivided into siltstones, mudstones, and claystones based on grain size. The term shale commonly refers to a mu...Mudrocks are made of >50% particles in the mud size fraction (<1/16 mm). They can be subdivided into siltstones, mudstones, and claystones based on grain size. The term shale commonly refers to a mudrock that shows fissility. Mudrocks can be described based on grain size, texture, color, mineralogy, fossils, and a variety of other factors. The clay minerals in mudrocks can have physical properties that them economically important.
