How does heat and pressure change minerals?

A metamorphic rock is a sedimentary or igneous rock that has had heat or pressure alter its form, or the size, shape, and arrangement of its minerals. The presence of certain specific minerals in a metamorphic rock can reveal the amount of heat and pressure that the rock experienced.

Heat is the main source of energy required for the chemical reactions that drive metamorphism.

Gravity pulls the earth's crust downward, creating pressure within the earth, which rises with depth like heat does. This pressure has the ability to physically compress the spaces between the minerals in the rock, making it denser. When heat and pressure work together, the rock flows rather than fractures, causing the mineral grains to realign, flatten, and lengthen.

Heat and pressure can change minerals through processes like recrystallization, where minerals reform into new crystal structures, and metamorphism, which alters mineral composition and texture without melting them.

Heat and pressure can change minerals through a process called metamorphism. This process occurs within the Earth's crust or mantle due to tectonic forces, resulting in the transformation of existing minerals into new minerals. The combination of heat and pressure alters the mineral's crystal structure, composition, and texture. Heat provides the energy needed for chemical reactions to occur, while pressure influences the arrangement of atoms within the mineral. These changes can lead to the formation of new minerals with different physical and chemical properties compared to the original minerals. Metamorphism often occurs in regions undergoing mountain building, subduction zones, or deep within the Earth's crust where high temperatures and pressures are present.