Childrenite is a rare hydrated phosphate mineral with elements iron, manganese, aluminium, phosphorus, oxygen and hydrogen. Its chemical formula is (Fe2+ ,Mn)2+ AlPO 4(OH) 2•H 2O and it has a molecular weight of 229.83 g/mol. Its specific gravity is 3.2 and it has a Mohs hardness of 4.5 to 5.