tyyolite tuff rock
Rhyolite Rock Facts: Geology and Uses Rhyolite is a silicarich igneous rock found throughout the world. The rock received its name from German geologist Ferdinand von Richthofen (better known as the Red Baron, a World War I flying ace).The word rhyolite comes from the Greek word rhýax (a stream of lava) with the suffix "ite" given to rocks.