A person who studies rocks is called a geologist. Geologists explore Earth's solid components, including rocks, minerals, and soils, and investigate the processes that shape them. They conduct fieldwork, collect samples, and analyze geological formations to understand the planet's history, structure, and natural resources. Their work has applications in various fields such as environmental science, natural hazard assessment, petroleum and mineral exploration, and understanding climate change. Through the study of rocks, geologists can also provide insights into past climates and biological evolution on Earth.