What is the term for a scientist who studies rocks?

The term for a scientist who studies rocks is "geologist." Geologists focus on understanding the Earth's structure, composition, and the processes that shape it over time, which includes the study of rocks and minerals. They examine rock formations, analyze their physical and chemical properties, and investigate the history recorded in the rock layers to understand geological events.

In contrast, a paleontologist primarily studies fossils and ancient life forms, a mineralogist specializes in the study of minerals, their structures, properties, and classifications, and a seismologist studies earthquakes and the propagation of seismic waves through the Earth. Each of these disciplines plays a different role in the broader field of Earth sciences, but the specific focus on rocks distinctly aligns with the role of a geologist.