Rock

Rock is a naturally occurring solid aggregate of one or more minerals or mineraloids. It is classified into three main types: igneous rock, sedimentary rock, and metamorphic rock. Rocks have been used by humans for millions of years, from early tools and weapons through to various construction materials. There are numerous fields of study and industries that deal with rocks including geology, petrology, and mining.

Types of Rock

Igneous Rock

Igneous rock is formed through the cooling and solidification of magma or lava. This process can occur beneath the Earth's surface to form intrusive igneous rocks, such as granite, or on the Earth's surface to form extrusive igneous rocks, such as basalt.

Sedimentary Rock

Sedimentary rock is formed from the accumulation of sediment that becomes compacted and cemented together. Sediment can include materials such as sand, silt, and clay, as well as the remains of living organisms. Examples of sedimentary rocks include limestone and sandstone.

Metamorphic Rock

Metamorphic rock is formed when existing rock is subjected to high temperatures and pressures, causing physical or chemical changes. This process, known as metamorphism, can result in rocks such as marble and slate.

Uses of Rock

Rocks have been used by humans for a variety of purposes throughout history. These include the construction of buildings and monuments, the production of tools and weapons, and the extraction of valuable minerals and metals.

See Also

• Geology
• Petrology
• Mining
• Mineral
• Mineraloid