The waterfall cascades over 100m of rhyolite cliffs, which once were a part of the huge Tweed Volcano. (byron-bay.com)
Indeed, this beach boasts rhyolite outcrop that dates to more than 50 million years ago. (fraserisland-australia.com)
Pumice is a highly vesicular pyroclastic igneous rock of intermediate to siliceous magmas including rhyolite, trachyte and phonolite. (sciencedaily.com)