Iron phosphates
Iron phosphates are called the phosphorus compounds of iron .
Iron (II) phosphate , old names ferrophosphate , Ferrum phosphoricum oxydulatum or phosphoric acid iron oxydul , chemical formula Fe 3 (PO 4 ) 2 · 8 H 2 O , forms colorless crystals that are insoluble in water and ethanol. It is formed from iron (II) sulfate and sodium phosphate , for example . The natural mineral is called Vivianite . In homeopathy it belongs to the Schuessler salts .
Iron (III) phosphate , old names ferric phosphate , Ferrum phosphoricum oxydatum or phosphoric acid iron oxide , chemical formula FePO 4 · n H 2 O ( n usually 2 or 4), forms yellowish crystals that are in acids, but not in water or ethanol to solve. It is used, among other things, as a molluscicide .
Iron diphosphate , old names iron pyrophosphate , ferripyrophosphate , Ferrum pyrophosphoricum or pyrophosphoric iron oxide , has the chemical formula Fe 4 (P 2 O 7 ) 2 · 9 H 2 O and is a diphosphate . It is sparingly soluble in water or acids.