Pyroxene
Pyroxene, the name of a group of common rock-forming minerals. The pyroxenes are silicates that also contain iron, magnesium, aluminum, or other metals in a wide range of compositions. Dark-colored igneous rocks such as basalt and diabase contain pyroxenes. Jadeite is a pyroxene form of jade, a semiprecious stone. Pyroxenes have been found to be abundant in lunar rocks.