greenstone

American  

[green-stohn] / ˈgrinˌstoʊn /

noun

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

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greenstone British  

/ ˈɡriːnˌstəʊn /

noun

1. any basic igneous rock that is dark green because of the presence of chlorite, actinolite, or epidote

2. a variety of jade used in New Zealand for ornaments and tools

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greenstone Scientific  

/ grēn′stōn′ /

1. 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.

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Etymology

Origin of greenstone

First recorded in 1765–75; green + stone

Example Sentences

Houses and a “polished greenstone axe” dating to around 3800 B.C. have been excavated at Horton, west of London.

From The Wall Street Journal • Jan. 23, 2026

The box also held three ceramic vessels, ear flares and a pair of greenstone beads.

From Reuters • Sep. 25, 2023

Trapped within them are bands of iron-rich rock, called greenstone belts, which are the remnants of ocean crust that got squeezed between the cratons in ancient continental collisions.

From Science Magazine • Feb. 15, 2023

About 2.7 billion years ago, basalt lava flowed underwater near what’s now the state’s border with Canada; the lava hardened, and the creep of geologic time turned it into a bedrock of greenstone and granite.

From New York Times • Oct. 12, 2017

Where the greenstone becomes porphyritic, the feldspar is a light green.

From Scenes and Andventures in the Semi-Alpine Region of the Ozark Mountains of Missouri and Arkansas by Schoolcraft, Henry Rowe