Magnetite and Maghemite (IMAGE) American Institute of Physics Caption In bulk powders the oxidation of magnetite to maghemite is shown by a change in color from black to red, but in nanoparticles it is not nearly so easy to distinguish the two phases. Credit Lara Bogart Usage Restrictions This image may be used only with appropriate credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.