Scientific study of rocks, including their composition, texture, and structure; occurrence and distribution; and conditions of origin.
Petrology is concerned with all three major types of rocks: igneous, metamorphic, and sedimentary. The subdiscipline of experimental petrology involves synthesizing rocks in the laboratory to ascertain the physical and chemical conditions under which they form. The subdiscipline of petrography is concerned primarily with the systematic study and description of rocks using a petrographic microscope.