Rock (geology)

Rocks are solid pieces that make up the Earth. They are everywhere, from the ground we walk on to the tall mountains we see far away. People have used rocks for tools and buildings for thousands of years.

Rocks come in three main kinds. Igneous rocks form when hot, melted rock cools down. Sedimentary rocks are made from tiny bits of older rocks that settle and stick together. Metamorphic rocks change when they are pushed and heated deep inside the Earth.

We find rocks on Earth and even in space! Planets like Mars and Venus are made of rock, just like our Earth. Scientists sometimes bring space rocks to study them.

Rocks help us every day. We use them to build houses, roads, and even to make things like concrete. Mining lets us get useful materials such as metals from rocks. Learning about rocks helps us understand our Earth and how it was formed long ago.