greenstone

[ green-stohn ]
/ ˈgrinˌstoʊn /

noun

any of various altered basaltic rocks having a dark-green color caused by the presence of chlorite, epidote, etc.

Origin of greenstone

First recorded in 1765–75; green + stone
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for greenstone

British Dictionary definitions for greenstone

greenstone

/ (ˈɡriːnˌstəʊn) /

noun

any basic igneous rock that is dark green because of the presence of chlorite, actinolite, or epidote
a variety of jade used in New Zealand for ornaments and tools
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for greenstone

greenstone

[ grēnstōn′ ]

Any of various green metamorphic rocks formed from igneous rocks that have a relatively low silica content and owe their color to the presence of a green mineral such as chlorite, hornblende, or epidote.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.