Rhyolite is one of the important type of rocks. If we have to define Rhyolite in general, Rhyolite is a fine-grained igneous rock which is rich in silica. Rhyolite comes under Igneous Rocks. All Igneous Rocks have similar properties and formation process. Along with Rhyolite Definition, know more about the History of Rhyolite, Etymology of Rhyolite in next sections.