Metamorphism

[metə'mɔːfɪz(ə)m] or [mɛtə'mɔrfɪzm]

Definition

(noun.) change in the structure of rock by natural agencies such as pressure or heat or introduction of new chemical substances.

Edited by Lilian--From WordNet

Definition

(n.) The state or quality of being metamorphic; the process by which the material of rock masses has been more or less recrystallized by heat, pressure, etc., as in the change of sedimentary limestone to marble.

Checker: Mario