Nucleation and growth of Mg-bearing calcite in a shallow, calcareous lake

- Precipitating Mg-bearing calcite particles are single crystals with aggregate-like morphology.
- Mg-bearing calcite nucleates heterogeneously on flakes of smectite.
- Nucleation and growth on a template result in distinct grain sizes and morphologies.
- In a shallow lake calcite precipitation is influenced by resuspended clays.