greenstone

views updated May 08 2018

greenstone A low-grade, regional metamorphic rock containing actinolite, epidote, and albite, and lacking a cleavage. Greenstones form by metamorphism of basic igneous rocks, the actinolite and epidote components being derived from the ferromagnesium minerals present in the original rock. Actinolite and epidote impart a green colour to the massive rock, hence the name ‘greenstone’.

A Dictionary of Earth Sciences AILSA ALLABY and MICHAEL ALLABY

greenstone

views updated May 29 2018

green·stone / ˈgrēnˌstōn/ • n. Geol. a greenish igneous rock containing feldspar and hornblende. ∎  chiefly NZ a variety of nephrite.

The Oxford Pocket Dictionary of Current English

More From encyclopedia.com

About this article

greenstone

All Sources -
Updated Aug 08 2016 About encyclopedia.com content Print Topic

You Might Also Like