Here's why:
* Mt Augustus is a monolith, not a single rock. A monolith is a large, single piece of rock that has been exposed by erosion. Mt Augustus is formed from a large igneous intrusion (a body of solidified magma) that has been exposed over time.
* The "largest single rock" is debatable. There's no universally accepted definition of "single rock" in geology. Some argue that the largest single rock is actually Uluru (Ayers Rock) in Australia, which is also a monolith, but with a different composition and a more iconic shape.
So, while Mt Augustus is an impressive and vast rock formation, it's not necessarily the "largest single rock" in the world. The title is more accurately claimed by Uluru, or perhaps by other monolithic formations around the world.
