Here's why:
* Igneous rocks are formed directly from the cooling and crystallization of magma (molten rock beneath the Earth's surface) or lava (molten rock erupted onto the Earth's surface).
* Sedimentary rocks are formed from the accumulation and cementation of sediments (like sand, mud, or shells).
* Metamorphic rocks are formed when existing rocks (igneous, sedimentary, or even other metamorphic rocks) are transformed by heat, pressure, or chemical reactions.
So, while there are many different types of igneous rocks, they all share the common origin of solidification from molten material.
