rhyolitePronunciation: /ˈrʌɪəlʌɪt/Definition of rhyolite noun [mass noun] Geology a pale fine-grained volcanic rock of granitic composition, typically porphyritic in texture. Origin: mid 19th century: from German Rhyolit, from Greek rhuax 'lava stream' + lithos 'stone'rhyolite in other Oxford dictionaries Definition of rhyolite in the US English dictionary
