Fig. 2

a Symmetric and asymmetric projections of the rhombohedral calcite geometry. b Validation of interface energy anisotropy formulation corresponding to the asymmetric left-handed 2D projection. A spherical grain evolves to its equilibrium shape while retaining a constant volume. The final crystal shares a diffuse interface of finite width with the surrounding liquid. The shape and size of the crystal are defined by the isoline corresponding to \(\phi _{\text {grain}}=0.5\)