Igneous rock is a type of rock that forms through the solidification and cooling of molten material known as magma or lava. There are two main types of igneous rocks based on where they solidify:
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Intrusive (or Plutonic) Igneous Rocks: These rocks form when magma cools and solidifies below the Earth's surface. Because the cooling process is slow, intrusive igneous rocks typically have large, well-formed crystals. An example of this type is granite.
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Extrusive (or Volcanic) Igneous Rocks: These rocks form when lava cools and solidifies on the Earth's surface. The cooling occurs rapidly, leading to smaller crystals or a glassy texture. An example of an extrusive igneous rock is basalt.
Igneous rocks are characterized by their mineral composition and texture, and they play a key role in the rock cycle and the formation of other rock types through processes like weathering and metamorphism.