The most common type of rock found on Earth is basalt. Basalt is an igneous rock formed from the rapid cooling of volcanic lava. It is primarily composed of silica, iron, magnesium, and other elements, making it denser than other types of rocks. Basalt makes up a significant portion of the Earth’s oceanic crust and is also found in volcanic regions on land. Its formation occurs as lava erupts from magma beneath the Earth’s surface, cools quickly upon contact with air or water, and solidifies. The prevalence of basalt is a key factor in the geological structure and composition of the planet.