Igneous rock is formed from lava that cools and solidifies. As it emerges from volcanic eruptions, lava can cool rapidly on the surface, leading to the formation of extrusive igneous rocks, such as basalt or pumice. Alternatively, if the lava cools slowly beneath the Earth's surface, it forms intrusive igneous rocks like granite. The texture and mineral composition of these rocks vary depending on the cooling rate and the chemical makeup of the lava. Igneous rocks are essential components of the Earth's crust and provide valuable insights into geological processes.