19. Igneous rocks undergo solidification from molten rocks. When Intrusive igneous rocks solidify,
they cool slowly forming large crystals which are
Intrusive, or plutonic, igneous rock forms when magma is trapped deep inside the Earth. … Intrusive rocks have a coarse grained texture. Extrusive Igneous Rocks: Extrusive, or volcanic, igneous rock is produced when magma exits and cools above (or very near) the Earths surface.