Underground igneous rocks form when magma is absorbed into small pockets. Also known as crystallization. As the magma cools slowly it becomes igneous rocks. Igneous rocks are also known as fire rocks. Intrusive rocks are igneous rock formed when magma hardened beneath earth's surface. Extrusive rocks are igneous rock formed from lava that erupted onto earths surface. Igneous rocks are used mostly for constructing. Granite a kind of igneous rock which is used for decoration
Pegmatite
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A very coarse-grained intrusive igneous rock.
A fine grained, extrusive igneous rock with a mineral composition similar to granite An intrusive igneous rock with large crystals surrounded by small crystals, forms when magma cools slowly at first, then rapidly. Volcanic glass formed as an extrusive igneous rock. |