This document discusses minerals and their properties. It defines minerals as naturally occurring inorganic solids with a definite chemical composition and crystalline structure. Minerals form crystals through processes involving cooling magma or dissolving and recrystallizing in solutions. Mineral groups are classified based on their chemical composition, with silicates being the most abundant. The document also outlines several methods for identifying minerals, including hardness, luster, specific gravity, streak, and cleavage/fracture. Finally, it discusses some uses of minerals as gems, ores containing useful elements that can be extracted, and titanium derived from specific minerals.