Intrusive rocks.
Igneous rock. Extrusive igneous rock forms at or near the surface, intrusive igneous rock forms below the surface.
The rock that forms on earth's surface is extrusive rock or otherwise known as a metamorphic rock.
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).
Igneous rock that forms below the Earth's surface is intrusive.
Such rock is extrusive igneous rock.
a Obsidion rock
Igneous rock. Extrusive igneous rock forms at or near the surface, intrusive igneous rock forms below the surface.
Intrusive igneous rock
pressure from the heat under the earths surface
The type of igneous rock that hardens under the earths surface is called the Intrusive Igneous Rock. Intrusive Igneous Rocks are of two main types, Hypabasal and Plutonic. The plutonic forms at deeper depths.
Obsidian
volcano