Rhyolite

Rhyolite is a volcanic rock formed from silica-rich magma that erupts explosively and cools quickly at the Earth’s surface, creating a fine-grained or glassy texture often in shades of pink, gray, or red. It is the extrusive equivalent of granite, composed mainly of quartz and feldspar, and is frequently associated with pumice, obsidian, and tuff. Because of its high viscosity, rhyolitic magma produces dramatic eruptions that scatter ash and pumice across wide areas, leaving behind striking flow banding and cavities that make specimens visually captivating. Historically, rhyolite has provided obsidian for sharp tools and pumice for abrasives, while collectors prize its patterned surfaces as symbols of fiery transformation and resilience.