Chlorite

Chlorite is a group of minerals, not a single mineral species, characterized by their layered structure and variable chemical composition. They are typically formed through the alteration of other minerals like pyroxenes, amphiboles, and micas in metamorphic and hydrothermal environments. Chlorites are often found in metamorphic rocks such as schists and phyllites, as well as in some igneous rocks. The appearance of chlorite varies depending on its composition, but it is commonly green, gray, or black, with a pearly to dull luster. Chlorite minerals are relatively soft and can be easily identified by their characteristic green color and platy or flaky habit.