rhyolite

noun

rhy·​o·​lite ˈrī-ə-ˌlīt How to pronounce rhyolite (audio)
: a very acid volcanic rock that is the lava form of granite
rhyolitic adjective

Examples of rhyolite in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
And another outcrop in the valley below, Craig Rhos-y-felin, supplied most of the rhyolite. John Timmer, Ars Technica, 14 Aug. 2024 The mixture slowly cooled and fused into a tuff of rhyolite. Roger Naylor, The Arizona Republic, 11 Apr. 2024 The aquifer recharges, but slowly: Rain is rare and getting rarer, and what does not evaporate right off takes its time to seep through all the layers of dirt and volcanic ash and limestone and granite and rhyolite and basalt. Matthew Gavin Frank, Harper's Magazine, 21 Oct. 2022 There was likely an intrusion of new magma under the volcano a few years before the 2011 eruption, so that event may have primed the rhyolite to erupt and caused the faults to become less stable as the stresses changed. Erik Klemetti, Discover Magazine, 10 Mar. 2022

Word History

Etymology

German Rhyolith, from Greek rhyax stream, stream of lava (from rhein) + German -lith -lite

First Known Use

1861, in the meaning defined above

Time Traveler
The first known use of rhyolite was in 1861

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Cite this Entry

“Rhyolite.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rhyolite. Accessed 10 Sep. 2025.

Kids Definition

rhyolite

noun
rhy·​o·​lite ˈrī-ə-ˌlīt How to pronounce rhyolite (audio)
: a very acid volcanic rock that is the lava form of granite
rhyolitic adjective

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