Igneous Rocks

Front

What are igneous rocks?

Back

Igneous rocks are formed from the cooling and solidification of molten rock material called magma or lava.

Front

What is the difference between coarse-grained and fine-grained igneous rocks?

Back

Coarse-grained igneous rocks have larger crystals and are formed from slow cooling magma, while fine-grained igneous rocks have smaller crystals and are formed from rapidly cooling lava.

Front

What is an example of a coarse-grained igneous rock?

Back

Granite is an example of a coarse-grained igneous rock.

Front

What is an example of a fine-grained igneous rock?

Back

Basalt is an example of a fine-grained igneous rock.

Front

How do igneous rocks form?

Back

Igneous rocks form when magma cools and solidifies either beneath the Earth's surface (intrusive) or on the surface after a volcanic eruption (extrusive).

Front

What is the texture of porphyry?

Back

Porphyry is characterized by a mixed texture, with larger crystals (phenocrysts) embedded in a finer-grained matrix.

Front

What type of cooling leads to the formation of large crystals in igneous rocks?

Back

Slow cooling of magma leads to the formation of large crystals in igneous rocks.

Front

What is obsidian and how is it classified?

Back

Obsidian is a volcanic glass that is classified as a fine-grained igneous rock due to its rapid cooling.

Front

What is the significance of crystal size in igneous rocks?

Back

Crystal size in igneous rocks indicates the cooling rate of the magma; larger crystals suggest slower cooling, while smaller crystals indicate rapid cooling.

Front

What are intrusive igneous rocks?

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Intrusive igneous rocks are formed from magma that cools and solidifies beneath the Earth's surface.