Ferumoxides [USAN]; Ferumoxides; AMI-25; CCRIS 6722; Fe(II) and Fe(III) are present (Mossbauer Spectroscopy; Feridex; Feridex I.V.; Physical form is a colloidal particle of nonstoichiometric magnetite; Superparamagnetic iron oxide; UNII-G6N3J05W84; Iron oxide crystal is inverse spinel (X-ray data)