Minerals form primarily through one of three processes: crystallization, crystallographic transformations or melting. Minerals may form in many environments, and their physical surroundings determine how minerals are produced. Most form using the method of crystallization, which begins with the evaporation of water into the atmosphere.
Conditions must be right for crystallization to occur. Salt water is a key ingredient for starting the process. Salt water, which evaporates from oceans and other bodies of saline water, contains electrically charged atoms. These atoms may appear individually or in clusters called ions. As seawater evaporates, water salinity increases. Eventually, saline becomes so concentrated that ions bind together like glue to form mineral crystals. These crystals then attach to each other, eventually forming large minerals.
Minerals can also form through melting. This formation occurs as a result of volcanic activity. During melting, magma, lava and other molten rock-forming liquids cool and form crystals. As with crystallization, the crystals bind together to form large stones. While minerals produced by crystallization often stand alone, those formed by melting are often embedded in surrounding layers of rock.
Lastly, minerals may form during crystallographic transformation. This process takes place where there is a change in ambient pressure or temperature. These changes cause minerals to become chemically unstable and, in turn, form new shapes.