Intrusive igneous rocks form within the Earth
Igneous rock. Extrusive igneous rock forms at or near the surface, intrusive igneous rock forms below the surface.
Igneous rock that forms below the Earth's surface is intrusive.
It forms an igneous rock. If it is within the Earth, then it is an intrusive igneous rock (e.g. granite) and if it is erupted onto Earth's surface then it is an extrusive igneous rock (e.g. basalt).
Intrusive igneous rock
Such rock is extrusive igneous rock.
Obsidian
Intrusive igneous rock (plutonic rock).
a Obsidion rock
Intrusive igneous rock
extrusive igneous rock
extrusive because it forms on or near earths surface
Intrusive igneous rock