Schists are metamorphic rocks that exhibit a plated structure known as schistosity in which the component minerals are readily visible to the unaided eye. Due to this characteristic structure, schists easily split along cleavage lines into thin flexible layers.

View a second image of Chlorite Schist

Schists are usually differentiated from other foliated rocks on the basis of their crystal size, exhibiting crystals that are distinctly larger than those of slates and considerably smaller than gneisses. Schists are often distinguished from one another, however, based upon the dominant flaky minerals they contain. Some of the more common varieties are mica schist, talc schist, and hornblende schist. These and other schists are particular prevalent among the Precambrian rocks.

Chlorite schist is a type of schist that contains appreciable quantities of a chlorite. Chlorites are a group of pervasive silicate minerals that are usually produced as alteration products of other minerals. Thus, they are widespread in rocks formed through metamorphism. Chlorites are typically green in color and often bestow this hue to the rocks in which they are contained. Chlorite schists, therefore, are characteristically olive or jade-like in color and in some areas are known as greenschists. In China, small pieces of these rocks are utilized for medical purposes, especially as a treatment for excessive phlegm.