Here's why:
* Metamorphic rocks are formed when existing rocks (igneous, sedimentary, or even other metamorphic rocks) are transformed by heat, pressure, or chemical reactions.
* Scoria is a type of extrusive igneous rock, meaning it forms from volcanic eruptions. It's characterized by its porous, bubbly texture, which is created by trapped gas bubbles that solidified as the lava cooled.
So, while scoria might undergo some changes over time, it's not considered a metamorphic rock because its origin and formation process are distinctly igneous.
