Crystal structure of aluminum sulfate hexadecahydrate and its morphology

A single‐crystal structure of aluminum sulfate hexadecahydrate (Al 2 (SO 4 ) 3 ·16H 2 O) was captured with a polarizing microscope. The structure was similar to a hexagonal plate and consistent with the predicted morphology derived from the modified AE model. An octagonal plate morphology was first obtained in a vacuum but was transformed into hexagonal plate‐like when the effect of the solvent with two disappearing {1 1 0} and {1 0 −1} faces was considered.