Figure S1. Raman spectra of elongated calcite precipitated in alkaline silica gel without the presence of glycine.

Figure S2. Raman spectra of calcium carbonate particles precipitated in different position along alkaline silica gel under 2 mg/ml of glycine from CaCl2 solution: (a) rhombohedral particle in the upper part of the gel; (b) and (c) star-shaped particle in the deeper part of the gel; (d) nearly spherulitic particle in the deepest part of the crystallization zone of the gel.

Figure S3. (a) Raman spectra of spherical particle at three days (black) and one week (red) crystallization; (b) The same Raman spectra of (a) but only shows the data from 1050 cm-1 to 1110 cm-1.