Q:

How many types of rocks are there?

A:

Quick Answer

There are three basic rock types that make up the geology of the Earth. They are igneous rocks, sedimentary rocks and metamorphic rocks. The rock type is defined by the way the rocks were created.

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Full Answer

Igneous rocks are formed from molten material, such as lava or magma. When the molten material cooled, the minerals crystallized into a tightly packed structure, making these rocks very strong.

Sedimentary rocks are formed at the Earth's surface from materials like sand, clay and mud. These rocks form in layers and are typically brown to light gray. Because they were formed on the Earth's surface, sedimentary rocks often house fossils.

Metamorphic rocks are created when existing rock is exposed to heat and pressure. The heat and pressure alters the form of the existing material. Metamorphic rocks may be formed from sedimentary or igneous rocks.

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Related Questions

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    A:

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