Basalt is one of the important type of rocks. If we have to define Basalt in general, Basalt is a common extrusive igneous rock formed by the rapid cooling of basaltic lava exposed at or very near the surface of Earth. Basalt comes under Igneous Rocks. All Igneous Rocks have similar properties and formation process. Along with Basalt Definition, know more about the History of Basalt, Etymology of Basalt in next sections.