* Metamorphic rocks form from existing rocks (igneous, sedimentary, or even other metamorphic rocks) due to intense heat and pressure deep within the Earth.

* Lava is molten rock on the Earth's surface. It originates from the mantle (a layer beneath the Earth's crust) and is considered igneous rock.

The process:

1. Melting: The intense heat deep within the Earth can cause metamorphic rocks (or any other type of rock) to melt.

2. Magma: The melted rock underground is called magma.

3. Eruption: If the magma rises to the surface through a volcano, it's called lava.

So, while metamorphic rocks can melt and become magma, the magma itself is not considered a metamorphic rock. It becomes an igneous rock (lava) once it erupts onto the Earth's surface.