How Rocks Change
Earth's rocks are always changing. Heat, pressure, weathering, and melting transform rocks over millions of years.
Three Rock Types
Igneous rocks form from cooled magma.
Sedimentary rocks form from layers of sediments.
Metamorphic rocks change because of heat and pressure.
The Rock Cycle
No rock stays the same forever. Rocks can melt, cool, break apart, become buried, or change into another rock type.