Answer:
During the process of metamorphic rock formation, there is a transformation or change in the mineral composition and texture of the original rock due to high heat, pressure, or chemically active fluids. As a result, the system goes through a significant change.
The system may be considered "stable" again once the metamorphism process has completed and the resulting metamorphic rock has reached equilibrium - meaning that there are no longer any changes occurring within the rock due to external factors. The stability of a metamorphic rock depends on various factors such as the mineral composition, temperature, pressure, and chemical environment. Once these factors balance out and reach a steady state, the system can be considered stable again.