Respuesta :

Dayum with the caps...
Igneious forms by cooling magma- metamorphic is a rock put under extreemly high temps and pressures 

Igneous rocks can be porous and have gas pockets whereas metamorphic are extremly dense with little to no porosity.

Compare: 
Both may have large silica contents 
Both are created under very hot temperatures

Hope it helps ;)

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