Table 1.

Examples of the diversity of biominerals. This list is by no means comprehensive, where some 70 different mineral phases have been identified to date.^1–11

Biogenic Minerals	Formula	Organism	Biological Location	Biological Function
Calcium Carbonates (calcite, vaterite, aragonite, Mg-calcite, amorphous)	CaCO3 (Mg,Ca)CO3 CaCO • nH2O	Many marine organisms, Aves, Plants Mammals	shell, test, eye lens, crab cuticle, eggshells, leaves inner ear	exoskeleton, optical, mechanical strength, protection, gravity receptor, buoyancy device, Ca store
Calcium Phospates (hydroxylapatite, dahllite, octacalcium phosphate)	Ca10(PO4)6(OH)2 Ca5(PO4,CO3)3(OH) Ca8H2(PO4)6, ?	Vertebrates Mammals Fish, Bivalves	bone, teeth, scales, gizzard plates, gills mitochondria	endoskeleton, ion store, cutting/grinding, protection, precursor
Calcium Oxylates (whewellite, wheddellite)	CaC2O4 • H2O CaC2O4 • 2H2O	Plants Fungi Mammals	leaves hyphae renal stones	protection/deterrent, Ca storage/removal, pathological
Iron Oxides (magnetite, goethite, lepidocrocite, ferrihydrite)	Fe3O4 α-FeOOH, γ-FeOOH 5Fe2O3 • 9H2O	Bacteria, Chitons Tuna/salmon Mammals	intracellular, teeth, head, filaments, Ferritin protein	magnetotaxis, magnetic orientation, mechanical strength, iron storage
Sulfates (gypsum, celestite, barite)	CaSO4 • 2H2O SrSO4 BaSO4	Jellyfish Acantharia Loxodes, Chara	statoconia cellular intracellular statoliths	gravity receptor skeleton gravity device/receptor
Halides (flourite, hieratite)	CaF2	Mollusc, Crustacean	gizzard plate statocyst	crushing gravity perception
Sulfides (pyrite, sphalerite, wurtzite, galena, greigite)	FeS2 ZnS, PbS Fe3S4	Thiopneutes	cell wall	sulfate reduction/ion removal?
Silicon oxides (silica)	SiO2 • nH2O	Diatoms Radiolaria Plants, etc.	cell wall cellular leaves	exoskeleton skeleton protection