diorite

American  

[dahy-uh-rahyt] / ˈdaɪ əˌraɪt /

noun

1. a granular igneous rock consisting essentially of plagioclase feldspar and hornblende.

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diorite British  

/ ˌdaɪəˈrɪtɪk, ˈdaɪəˌraɪt /

noun

1. a dark coarse-grained igneous plutonic rock consisting of plagioclase feldspar and ferromagnesian minerals such as hornblende

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diorite Scientific  

/ dī′ə-rīt′ /

1. A gray, coarse-grained plutonic rock. Diorite consists mainly of sodium-rich plagioclase and one or more mafic minerals such as biotite, hornblende, or pyroxene. It is the coarse-grained equivalent of andesite.

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Other Word Forms

Derived Forms

• dioritic
  adjective

Etymology

Origin of diorite

1820–30; < French < Greek dior ( ízein ) to distinguish ( see di- ³, horizon) + French -ite -ite ¹

Example Sentences

Researchers started with an exceptionally fast-weathering rock called quartz diorite and ground it to speed things up even more.

From Nature • May 3, 2020

These dark ferromagnesian minerals are commonly found in gabbro, basalt, diorite, and often form the black specks in granite.

From Textbooks • Jan. 1, 2017

Curious members of a penguin colony on Cape Leogoupi watched as he pounded on slabs of black granite and diorite rising out of the southern ocean.

From Washington Times • Feb. 20, 2015

Carved from black diorite, it is 30 inches tall, headless, but inscribed with cuneiform that says it was placed in a temple in Ur, in what is now southern Iraq, to please the god Enil.

From New York Times • Sep. 7, 2010

I’d fallen into a slow, hypnotic rhythm—swing, swing; kick, kick; swing, swing; kick, kick— when my left ice ax slammed into a slab of diorite a few inches beneath the rime.

From "Into the Wild" by Jon Krakauer