The Petrified Forest national park lies in close proximity to Holbrook in  northeastern Arizona. It belongs geologically to the Colorado plateau. The layers of the Upper- Trias open-lying here offer a multiplicity of places of discovery for silificed wood. This petrified wood may not be collected in the national park. Even the picking of small fragments is strictly punished.

However there are lying other finding locations also outside of the park, which serve the market with this beautiful material. In the USA it is named „Rainbow petrified wood “. The cause for the name is that the wood occurs in all colours -  which can show up often also in one specimen. The material accepts a middle to strong glassy polish when polished - depending upon its structure .