Explanation

Also called schistosity. A structure in metamorphic rock formed by continuous parallel arrangement of lamellar or columnar minerals such as mica, chlorite, talc, hornblende, etc. It is the most common structure in metamorphic rock. Its constituent minerals are generally coarse in grain size, and can be distinguished from phyllitic structure (fine in grain) by the naked eye. The plane formed by parallel arrangement of minerals is called a schistosity plane. The foliated surface can be a relatively straight surface or a wavy surface. It is often consistent with the bedding plane of the original rock, but sometimes it can also intersect diagonally.

Classification