Which type of rock is formed from the cooling and solidification of lava at Earth’s surface?

The formation of extrusive igneous rock occurs when lava that reaches Earth's surface cools and solidifies. This process typically takes place rapidly due to exposure to air or water, leading to the formation of fine-grained textures in these rocks. Common examples of extrusive igneous rocks include basalt and pumice, which show characteristics that arise from the quick cooling of lava.

In contrast, intrusive igneous rocks form from magma that cools and solidifies beneath Earth's surface. The slower cooling process allows for the growth of larger crystals. Sedimentary rocks, on the other hand, are formed from the accumulation and compression of sediment over time, while metamorphic rocks originate from the alteration of existing rocks under heat and pressure. This clarification helps to see how extrusive igneous rock specifically is defined by its origin from surface lava cooling.