|any of a group of silicate minerals having the general formula ABSi2O6, where A is usually calcium, sodium, magnesium, or iron, and B is usually magnesium, iron, chromium, manganese, or aluminium. Pyroxenes occur in basic igneous rocks and some metamorphic rocks, and have colours ranging from white to dark green or black. They may be monoclinic (clinopyroxenes) or orthorhombic (orthopyroxenes) in crystal structure. Examples are augite (the most important pyroxene), diopside, enstatite, hypersthene, and jadeite|
|pyroxene (pī-rŏk'sēn') Pronunciation Key
Any of a series of dark silicate minerals having the general chemical formula ABSi2O6, where A is either calcium (Ca), sodium (Na), magnesium (Mg), or iron (Fe), and B is either magnesium, iron, chromium (Cr), manganese (Mn), or aluminum (Al). Pyroxenes vary in color from white to dark green or black and are characterized by a rectangular-shaped cross section. They can be either monoclinic or orthorhombic and occur in igneous and metamorphic rocks. The minerals enstatite, diopside, and augite are pyroxenes.