Oriented attachment involves spontaneous self-organization of adjacent particles, so that they share a common crystallographic orientation, followed by joining of these particles at a planar interface. Bonding between the particles reduces overall energy by removing surface energy associated with unsatisfied bonds through elimination of the mineral-air or mineral-fluid interface. In addition to oriented attachment, particle growth can also involve attachment characterized by a small misorientation in the interface. For imperfect oriented attachment the formation of TiO2 nanocrystals can be cited as an example. Another example of oriented attachment is the formation of nanospindle, nanorhombohedron and nanocube structured α-Fe2O3 which can be synthesized by the solvothermal method. An intermixing of ethylenediamine (EN) either with ethanol (EtOH) or water can be used to generate the structural forms of α-Fe2O3. During synthesis, EN functions as a ligand and facilitates the growth of nanostructures through oriented attachment of primary nanocrystals. Dislocations are common defects in solids, yet all crystals begin as dislocation-free nuclei. When nanocrystalline materials grow by oriented attachment at crystallographically specific surfaces, there is a small misorientation at the interface and dislocations result.