Minerals are substances that occur naturally on Earth, in the absence of life. This means they are inorganic in nature, not made or produced by living organisms, although they do support them in many ways.
Minerals are an important part of the ecosystem and provide different functions, such as regulating body temperature and providing nutrients to plants. Minerals are also the main components of soil.
Common minerals include quartz, feldspar, mica, amphibole, olivine, and calcite.
A rock is an aggregate of one or more minerals or mineraloids. Some rocks, such as limestone or quartzite, are composed primarily of one mineral – calcite or aragonite in the case of limestone, and quartz in the latter case.
Other rocks can be defined by relative abundances of key minerals; a granite is defined by proportions of quartz, alkali feldspar, and plagioclase feldspar.
The other minerals in the rock are termed accessory minerals, and do not greatly affect the bulk composition of the rock.
Rocks can also be composed entirely of non-mineral material; coal is a sedimentary rock composed primarily of organically derived carbon.
