The Granite boulders that give Tibooburra its name and provided the gold that established the town are a distinctive feature of the townscape. Outcrops of boulders are found not only on the edges of town but on vacant blocks along the Main Street and give the town its unique character.
The granite tors or boulders around Tibooburra are the exposed remnants of an underground intrusion of a mass granite that is about 410 million years old. This hot rock cooked older sedimentary muds and sands and as the resulting slates folded, fluids containing gold in solution where pushed up the axis of the folds, precipitating quartz veins containing gold. These slates with their gold-bearing quartz veins were exposed to weathering and eroded during the Jurassic period 205 – 141 million years ago. Later during the Cretaceous period 141-35 million years ago sands built up over gravels eventually turning into sandstone.
The granite boulders form a remarkable contract to the sandstone used as the primary construction material for the major buildings in town, which comes from the quarries in the sandstone outcrop on the common.