A scientist who studies rocks is called a geologist. Geologists investigate the composition, structure, and processes of the Earth, including rock formations, minerals, and fossils. They play a crucial role in understanding the planet's history, predicting natural disasters, and finding resources such as oil and minerals. Geologists often conduct field studies, analyzing rock samples and geological formations to gather data. Their expertise is essential for areas such as environmental science, paleontology, and resource management. By studying rocks and geological processes, geologists contribute to our understanding of Earth's systems and how they impact our environment.