Intrusive, or plutonic, igneous rocks form when magma cools slowly below the Earth’s surface. Most intrusive rocks have large, well-formed crystals. Examples include granite, gabbro, diorite and dunite.
The Rock Cycle
Intrusive, or plutonic, igneous rocks form when magma cools slowly below the Earth’s surface. Most intrusive rocks have large, well-formed crystals. Examples include granite, gabbro, diorite and dunite.
Mineral Photos courtesy of R.Weller/Cochise College