Wonderstone

Wonderstone is a colorful variety of welded tuff, a super hot arial rhyolite volcanic ash flow which hardened when it hit the ground and over time these amazing bands were weathered into the stone by circulating groundwater interacting with microbes and metals like iron creating colorful bands of oxides and cementing the stone together further. 

Some wonderstone is very hard and practically a jasper, some is soft an better carving material. This is all dependent on the grain size of the ash fall and how much silica rich water soaks into the stone allowing it to become harder than the already very hard welded tuff its composed of.