Hydrous CaCO3 gets a new structure

Solid-State Chemistry Calcium carbonate (CaCO3) forms important minerals on Earth and is a model system for understanding crystal nucleation. Three different structures of CaCO3 are known, along with two structures that are hydrated. Zou et al. found a third hydrated CaCO3 structure formed from amorphous CaCO3 in the presence of magnesium ions. The discovery illustrates the importance of amorphous precursors for producing new materials. Science , this issue p. [396][1] [1]: /lookup/doi/10.1126/science.aav0210