ZnO microcrystals, Ca₂Nb₃O₁₀ nanoplates, and LiMo₃Se₃ nanowires were used to chemically assemble CdSe and magnetite nanoparticles into discrete nanostructures. The CdSe-containing clusters exhibit directional and polarized light emission properties, which are modulated by the one- and two-dimensional morphology of the clusters. Clusters of Fe₃O₄ nanoparticles are superparamagnetic and contain one or two hard magnetic axes, depending on the cluster shape. The ability to control the physical properties of nanoparticles via assembly is of academic and practical interest. Nanostructures with directional emissive and magnetic properties could find applications in light emitting devices, as optical probes, and as magnetic sensors and actuators.