* Metamorphism: Metamorphism is the process where existing rocks (like limestone) are transformed into different rocks due to intense heat and pressure. The chemical and mineral composition of the rock changes, but it doesn't melt completely.

* Limestone to Marble: Limestone is primarily made of calcium carbonate (CaCO3). Under intense heat and pressure, the crystals in limestone recrystallize, forming a denser, more compact rock called marble.

Key points to remember:

* No melting: Metamorphism doesn't involve melting, unlike the process of magma formation.

* Solid-state transformation: The changes occur in the solid state.

* New minerals: The resulting marble often has a different texture and may contain different minerals than the original limestone.

Let me know if you have any other questions!