rhyolite

noun rhy·o·lite \ ˈrī-ə-ˌlīt \

Definition of rhyolite

: a very acid volcanic rock that is the lava form of granite

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rhyolitic

play \ˌrī-ə-ˈli-tik\ adjective

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Recent Examples of rhyolite from the Web

The highlight of the park is of course the gorge, where walls of red-gray rhyolite schist, a hard volcanic rock, rise up to 40 feet along the Eau Claire River.

— chelsey lewis, Milwaukee Journal Sentinel, "Dells of the Eau Claire is a gorgeous county park near Wausau," 2 Nov. 2017
Sept. 9 Leslie Gulch trip: Meet at the WinCo parking lot at Meridian Road and I-84 at 7:30 a.m. Saturday, Sept. 9, for an 8 a.m. departure. Sculpted rhyolite and geology with Oregon State geologist Mark Ferns.

— michelle jenkins, idahostatesman, "Pumpkins, football and FitOne…yep, September is just around the corner," 25 Aug. 2017
The Kaharoa eruption would have been impressive to see, producing ~5-7 km3 of rhyolite over what is thought to be a few years time.

— erik klemetti, WIRED, "The 1886 Eruption of Mt. Tarawera, New Zealand," 10 Feb. 2011

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