Rocks are the primary documents of Earth processes. Petrology is the scientific study of rocks, their composition, texture, structure, and origin. It encompasses igneous, sedimentary, and metamorphic rocks and the processes that form and transform them.

Hand-sample description, thin-section microscopy, whole-rock chemistry, and mineral analysis are standard tools. Experimental petrology reproduces rock-forming conditions in the laboratory. Field relations provide the context that laboratory data alone cannot supply.

Petrologic studies reveal how magmas evolve, how sediments become rocks, and how metamorphism records crustal conditions. The discipline underpins mineral and energy exploration and contributes to understanding planetary interiors. Every rock sample carries a history that petrology seeks to reconstruct.

• Scientific study of rocks and their origins
• Covers igneous, sedimentary, and metamorphic rocks
• Uses microscopy, chemistry, and experiments
• Reconstructs rock-forming processes