A hard-rock geologist is someone who specializes in studying solid and dense geological formations such as igneous and metamorphic rocks. This type of geologist is often involved in mineral exploration and mining projects where they analyze and map the underground geology to identify areas with high mineral concentrations. Synonyms for hard-rock geologists include lithologists, petrologists, and rock mechanics experts. While lithologists and petrologists focus on the composition and characteristics of rocks, rock mechanics experts study the properties of rocks under stress and strain. In addition to these specialties, geologists can also be categorized by the type of rock they specialize in, such as an igneous or metamorphic geologist.