plagioclase
noun
pla·gio·clase
ˈplā-j(ē-)ə-ˌklās 
ˈpla-,
-ˌklāz
: a triclinic feldspar
especially
: one having calcium or sodium in its composition
Examples of plagioclase in a Sentence
Recent Examples on the Web
The Alaska Volcano Observatory has posted some great images of the the ash (see above) collected from the Veniaminof eruption, including some that show the glassy shards with blades of plagioclase (microlites) in the volcanic glass.
—
Erik Klemetti, Discover Magazine, 23 Sep. 2013
Changing chemical composition of the magma can betray the rapid crystallization of the mineral plagioclase feldspar.
—Erik Klemetti, Discover Magazine, 14 Nov. 2018
Maaz, which is on top and thus probably younger, has a composition similar to most basaltic lava flows — full of minerals known as pyroxene and plagioclase but with little or no olivine.
—New York Times, 27 Apr. 2022
Basaltic lava has a low silica content and is composed predominantly of plagioclase, amphibole, and pyroxene.
—David Bressan, Forbes, 18 May 2021
The most common lava rock found at Mount St. Helens is indeed Dacite, composed predominantly of plagioclase feldspar and quartz (pure silicon-dioxide).
—David Bressan, Forbes, 18 May 2021
Here, partially melting of older voclanic and sedimenatyr rocks, together with water, forms a more differentiated rock type, composed of plagioclase, amphiboles, and micas; sometimes with minor amounts of pyroxenes and quartz.
—David Bressan, Forbes, 10 Mar. 2021
Basalt is a volcanic rock composed of augite and sometimes plagioclase and magnetite, which says nothing.
—Louise Erdrich, The New Yorker, 2 Sep. 2019
It’s mostly made of plagioclase, a rock formed out of molten magma.
—Brian Resnick, Vox, 15 July 2019
Erik Klemetti, Discover Magazine, 23 Sep. 2013
Changing chemical composition of the magma can betray the rapid crystallization of the mineral plagioclase feldspar.
—Erik Klemetti, Discover Magazine, 14 Nov. 2018
Maaz, which is on top and thus probably younger, has a composition similar to most basaltic lava flows — full of minerals known as pyroxene and plagioclase but with little or no olivine.
—New York Times, 27 Apr. 2022
Basaltic lava has a low silica content and is composed predominantly of plagioclase, amphibole, and pyroxene.
—David Bressan, Forbes, 18 May 2021
The most common lava rock found at Mount St. Helens is indeed Dacite, composed predominantly of plagioclase feldspar and quartz (pure silicon-dioxide).
—David Bressan, Forbes, 18 May 2021
Here, partially melting of older voclanic and sedimenatyr rocks, together with water, forms a more differentiated rock type, composed of plagioclase, amphiboles, and micas; sometimes with minor amounts of pyroxenes and quartz.
—David Bressan, Forbes, 10 Mar. 2021
Basalt is a volcanic rock composed of augite and sometimes plagioclase and magnetite, which says nothing.
—Louise Erdrich, The New Yorker, 2 Sep. 2019
It’s mostly made of plagioclase, a rock formed out of molten magma.
—Brian Resnick, Vox, 15 July 2019
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'plagioclase.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
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Cite this Entry
“Plagioclase.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/plagioclase. Accessed 24 Apr. 2024.
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