Wonder Stone is a type of Rhyolite:
The word rhyolite comes from the Green word for stream (rhyax) + the suffix lite. Rhyolite was named streaming rock because of its beautiful flow bands, which are made of bubble and crystal rich layers that form as the lava flows onto the surface and advances. Rhyolite can look very different, depending on how it erupts. Explosive eruptions of Rhyolite create pumice, which is white and full of bubbles. Effusive eruptions of Rhyolite often produce obsidian, which is bubble-free and black. The color of Rhyolite ranges widely, but generally is white or light yellow, brown or red. Most Rhyolites are flow banded; that is, they show streaky irregular layers that are formed by the flowing of the sticky, almost congealed magma. Wonder rock is found in many locations throughout the West.