This Bush Rock is said to be the very best available on the Gold Coast and Northern Rivers area. It is sourced from the Caldera of the Mt Warning Sheild Volcano and is natural surface rock. This means that the rock will have various types of natural lichen and moss growing on it. Not all rock has this type of growth but all rocks do have naturally occurring flat surfaces Ideal for building rock retaining walls. The type of rock you will expect to get will be basalt a naturally occurring rock from this area.