How different are extrusive igneous rocks from intrusive?

What are the features of intrusive igneous rocks and how do these rocks form? What are the features of extrusive igneous rocks and how do these rocks form? What is the difference between granite and gabbro? What is the difference between rhyolite and basalt? How does obsidian form? read more

Extrusive rocks and intrusive rocks both form when hot molten material crystallizes. However, extrusive rocks form from lava at the surface of the Earth, whereas intrusive rocks form from magma underground, often relatively deep in the Earth. A pluton is a block of intrusive igneous rock. read more

Extrusive igneous rocks form during lava flows and the like, while intrusive igneous rocks form in, well, intrusions underground. Because they cool so slowly, intrusive rocks can form larger crystals, while extrusive rocks tend to have much finer crystal structures, if any. read more

These are igneous rocks that are formed by the solidification of hot magma deep inside the earth’s crust. read more

Igneous rocks are formed from the solidification of molten rock material. There are two basic types. Intrusive igneous rocks crystallize below Earth's surface, and the slow cooling that occurs there allows large crystals to form. Examples of intrusive igneous rocks are diorite, gabbro, granite, pegmatite, and peridotite. read more