Chlorite is a group of layered silicate minerals. Ordinary chlorite means mainly Mg and Fe minerals such as clinochlore and oolitic chlorite. It is a rock-forming mineral of some metamorphic rocks. Magnesium ores in igneous rocks, such as biotite, amphibole and pyroxene, are liable to form chlorite under the action of low-temperature hot water. Its color varies with the iron content. Glass gloss to no gloss, cleavage surface can be Pearl gloss. It is mainly the product of mesothermal and cryogenic hydrothermal processes, shallow metamorphism and sedimentation.