Geochemistry is the study of the chemical composition and processes of the Earth and other planetary bodies. It combines principles from both chemistry and geology to understand how elements and compounds interact within the Earth's crust, atmosphere, and oceans. This field helps scientists analyze natural resources, understand environmental changes, and explore the origins of Earth materials. Researchers in geochemistry often examine minerals, rocks, and soils to determine their chemical makeup. They may also study the effects of human activities on the environment, such as pollution and resource extraction. Techniques used in geochemistry include mass spectrometry and chromatography, which help identify and quantify different substances.