One of the major groups of silicate minerals found in many igneous and metamorphic rocks. Pyroxene minerals are also common in meteorites. There are many different types of pyroxene. All of the types contain Si2O6 but some have sodium (Na) while others have iron (Fe), magnesium (Mg), or a combination of these three elements.
From → pyro- "fire," + xeno- a combining form meaning "alien, strange, guest," from Gk. xenos "stranger, guest." Pyroxene was originally supposed to be a foreign substance when found in igneous rocks.