Hureaulite is a manganese phosphate with the formula Mn²⁺₅(PO₃OH)₂(PO₄)₂·4H₂O. It was discovered in 1825 and named in 1826 for the type locality, Les Hureaux, Saint-Sylvestre, Haute-Vienne, Limousin, France. It is sometimes written as huréaulite,... Wikipedia