pla·​gio·​clase | \ ˈplā-j(ē-)ə-ˌklās , ˈpla-, -ˌklāz\

Definition of plagioclase

: a triclinic feldspar especially : one having calcium or sodium in its composition

Examples of plagioclase in a Sentence

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Your average Hood plagioclase crystal that formed 21,000 years ago might have spent only 1-12% of its entire history, a few hundred to a few thousand years, in conditions that would have allowed eruption of the magma (think: hot). Erik Klemetti, WIRED, "The Ephemeral Nature of Magma Prior to Eruption," 17 Feb. 2014

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'plagioclase.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of plagioclase

circa 1868, in the meaning defined above

History and Etymology for plagioclase

Greek plagios oblique + klasis breaking, from klan to break — more at clast

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The first known use of plagioclase was circa 1868

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