What is igneous rock?

Igneous rocks are one of the three major types of rock recognized by geologists, alongside sedimentary and metamorphic rocks. They are formed when molten rock cools and solidifies, which can happen with or without crystallization. Depending on how they form, these rocks can appear as plutonic bodies or volcanic extrusives.

What we know

• Igneous rock is one of the three major types of rock recognized by geologists. [2]
• Igneous rocks are created when molten rock cools and solidifies, with or without crystallization. [3]
• Igneous rocks may form as either plutonic bodies or volcanic extrusive structures. [3]

Where to go next

• compared withWhat are sedimentary rocks?
• what caused itHow do metamorphic rocks form?
• a case in pointWhat are volcanic rocks?
• a case in pointWhat is ultramafic rock?
• the bigger pictureWhat is a rock formation?
• an unexpected connectionHow is Earth's mantle related to igneous rocks?Earth's mantle is composed of ultramafic rocks, which are classified as igneous and meta-igneous rocks.

Sources

• [1]list of rock types (Wikidata Q918774) · CC0 1.0
• [2]List of rock types · CC BY-SA 4.0
• [3]List of rock formations · CC BY-SA 4.0
• [4]Volcanic rock · CC BY-SA 4.0
• [5]Ultramafic rock · CC BY-SA 4.0