The microscopic growth mechanism of gibbsite is examined via crystalli
zation in the presence of alkali metal ions, The morphology is found t
o be hexagonal plates in the presence of sodium, but hexagonal prisms
in the presence of potassium and caesium. The former morphology is ver
y similar to the calculated equilibrium morphology which ignores the e
ffect of the growth medium. Further calculations examining the possibl
e lattice sites of the incorporated defects show that different positi
ons are most stable for sodium and potassium/caesium, providing an exp
lanation for the different morphology.