Biomineralization is the process by which living organisms produce
minerals, often to harden or stiffen existing tissues. Such tissues are called
mineralized tissues. It is an extremely widespread phenomenon; all six taxonomic kingdoms contain members that are able to form minerals, and over 60 different minerals have been identified in organisms.
Examples include
silicates in
algae and
diatoms,
carbonates in
invertebrates, and
calcium phosphates and
carbonates in
vertebrates. These minerals often form structural features such as sea
shells and the
bone in
mammals and
birds.
Organisms have been producing mineralised
skeletons for the past 550 million years. Other examples include
copper,
iron and
gold deposits involving bacteria. Biologically-formed minerals often have special uses such as magnetic sensors in
magnetotactic bacteria, gravity sensing devices and iron storage and mobilization.