Chemically weathered stone
Chemical weathering causes the minerals in rocks to decompose. When the minerals are exposed to water, oxygen, acids and bases or carbon dioxide, they may react, resulting in a change in the overall composition of the rock.
Effects
According to Frank Press and Raymond Siever, the authors of "Understanding Earth," chemical weathering causes some rock minerals to dissolve and others to combine with water and components of the atmosphere, such as oxygen, to form new chemical compounds.
Dissolution
Rocks contain minerals. Some minerals dissolve in acids, bases or water. When rock minerals dissolve, they make the rocks they leave weak and vulnerable to fracture.
Hydrolysis
It's through hydrolysis that water is incorporated into a mineral's chemical structure, turning it into a new mineral. This process turns some minerals, such as feldspar, a key mineral in many rocks, into clay, making it weak and easy to break.
Oxidation
Rusting is a form of oxidation. Iron and other metals are present in many rock minerals. When they oxidize, they decompose, leaving rocks weakened and susceptible to breakage.
Example
Stalactites and stalagmites are made through chemical weathering.
Tags: minerals dissolve, rock minerals, acids bases, chemical weathering, into mineral
