mineralogy

Study of minerals. The classification of minerals is based chiefly on their chemical composition and the kind of chemical bonding that holds their atoms together. The mineralogist also studies their crystallographic and physical characters, occurrence, and mode of formation.

The systematic study of minerals began in the 18th century, with the division of minerals into four classes: earths, metals, salts, and bituminous substances, distinguished by their reactions to heat and water.