Mineral formation occurs through various natural processes, primarily involving the crystallization of minerals from molten rock, known as magma, or from solutions. As magma cools, minerals crystallize and grow, forming solid structures. Additionally, minerals can form through evaporation, where dissolved substances in water concentrate and solidify as the water evaporates. Another method of mineral formation is through metamorphism, where existing minerals change due to heat and pressure over time. This process can alter the mineral's structure and composition, resulting in new minerals. Understanding these processes helps geologists study the Earth's crust and the rock cycle.