A type of rhyolite found throughout Utah and a few other states. Utah Wonderstone has been collected for decades by rockhounds traveling U.S. Highway 36 near Vernon. Roadside shops often sold it as a “souvenir stone of Utah.”

Wonderstone provides a clear example of flow-banding in rhyolite, showing how volcanic glass and silica-rich lavas record movement as they cool. There is actually some open debate amoung geologists how this unique flow banding actually occurs.