"Plutonic" refers to igneous rocks that form deep within the Earth's crust from the slow cooling of magma. This process allows large crystals to develop, resulting in coarse-grained textures. Common examples of plutonic rocks include granite and gabbro, which are often found in mountain ranges and other geological formations. The term "plutonic" is derived from Pluto, the Roman god of the underworld, reflecting the deep, hidden origins of these rocks. Unlike volcanic rocks, which cool quickly on the Earth's surface, plutonic rocks provide valuable insights into the Earth's internal processes and the composition of its crust.