When exposed to heat pressure or fluids what can happen to mineral grains?

When exposed to heat, pressure, or fluids, mineral grains can undergo metamorphism, leading to changes in their texture and composition. This process may cause recrystallization, resulting in larger or more aligned grains, or the formation of new minerals through chemical reactions. Additionally, minerals can become deformed or altered, which can affect their physical properties and stability. These transformations are crucial in the formation of metamorphic rocks.