Biomineralization In article number 2301422, Song Chen, Helmut Cölfen, Bin Li, and co-workers report a novel and simple way to synthesize amorphous iron-calcium phosphate (Fe-ACP) particles with homogenous iron distribution and high stability in aqueous media. Their application yields calcium iron phosphate ceramics with superior mechanical strength and acid resistance. This presents a potential role in biomineralization and to fabricate acid-resistant high-performance bioceramics for bone and dental applications.