Clinopyroxene is a group of important rock-forming minerals found in many igneous and metamorphic rocks. They are typically characterized by their crystal structure, which includes a single chain of silicate tetrahedra. Common compositions include augite and diopside, which can vary in color from green to black. These minerals are significant in geology as they help scientists understand the conditions under which rocks form. Clinopyroxenes are often used in petrology to study the history of volcanic eruptions and the composition of the Earth's mantle, providing insights into geological processes.