anorthosite
|a-nor-tho-site|
🇺🇸
/əˈnɔrθəˌsaɪt/
🇬🇧
/əˈnɔːθəsaɪt/
plagioclase-rich igneous rock
Etymology
'anorthosite' originates from New Latin, specifically the word 'anorthite' (the mineral name) combined with the rock-forming suffix '-osite' (from '-ite'), where the mineral name 'anorthite' ultimately draws on Greek elements 'a(n)-' meaning 'not' and 'orthos' meaning 'straight' or 'correct'.
'anorthosite' developed from the New Latin mineral name 'anorthite' and related French/New Latin formation 'anorthosite' and was adopted into English scientific usage in the 19th century as the term for rocks composed largely of anorthite.
Initially used to denote rock composed chiefly of the mineral anorthite, the term's meaning has remained specialized and now broadly denotes any coarse-grained igneous rock dominated by plagioclase feldspar.
Meanings by Part of Speech
Noun 1
a coarse-grained intrusive igneous rock composed predominantly of plagioclase feldspar (especially anorthite), often forming large plutonic masses; common in the lunar highlands and in some continental crustal complexes on Earth.
Large anorthosite bodies make up much of the Moon's highland crust.
Synonyms
Noun 2
a single mass or outcrop of anorthosite rock (used in geology to refer to a specific body of rock).
Geologists mapped an anorthosite outcrop along the mountain ridge.
Synonyms
Last updated: 2025/08/19 08:22