pyroxene

UK: /paɪˈrɒksiːn/ US: (pī rok′sēn, pə-, pī′rok sēn′)

WordReference Random House Unabridged Dictionary of American English © 2025

py•rox•ene  (pī rok′sēn, pə-, pī′rok sēn′), n. 

1. Mineralogy any of a very common group of minerals of many varieties, silicates of magnesium, iron, calcium, and other elements, occurring as important constituents of many kinds of rocks, esp. basic igneous rocks. Cf. augite, diopside, hypersthene. 

• French; see pyro-, xeno-; origin, originally supposed to be a foreign substance when found in igneous rocks
• 1790–1800;

py•rox•en•ic  (pī′rok sen′ik), adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

pyroxene / paɪˈrɒksiːn/ noun

1. 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

Etymology: 19th Century: pyro- + -xene from Greek xenos foreign, because it was mistakenly thought to have originated elsewhere when found in igneous rocks