Impurity partitioning during colloidal crystallization was investigated for grains with different orientations. Particles of various sizes were doped as impurities during the growth of colloidal polycrystals. The effective partition coefficient, k(eff), which is the impurity concentration in the solid (C-S) divided by that in initial solution (C-L), was measured for grains oriented in the [111] and [100] directions normal to the growth direction. The [111]-oriented grains were found to have a larger k(eff)-than [100] -oriented grains. This was analyzed by using the Thurmond and Struthers model. Though both [111]- and [100] -oriented grains were face centered cubic (fcc) structures, within several layers of crystals, the volume fraction of [111] -oriented grains was larger than that of [100] -oriented grains, yielding a larger driving force for nucleation, Delta G(Tr), and thus a larger equilibrium partition coefficient, k(0), for [111] -oriented grains. (C) 2016 Elsevier B.V. All rights reserved.