This document discusses the study of mineralogy and properties of minerals and rocks. It defines mineralogy as the study of minerals, which are naturally occurring inorganic solids with a defined chemical composition and crystalline structure. It describes several physical properties used to identify common minerals such as luster, hardness, streak, cleavage, fracture and color. It also discusses the chemical composition of minerals and provides examples of important mineral resources in the Philippines. Finally, it classifies the three main types of rocks - igneous, sedimentary, and metamorphic - and provides brief descriptions.