Na-beta-Al2O3 powder after compaction and subsequent microwave irradiation yielded dense sintered products indicating preferred orientation along either the basal plane (0 0 2) or prismatic plane (2 2 0). The orientation depends on whether the starting material is a commercial powder or a precursor synthesized through wet-chemical route. The product from the latter powder exhibits uniform microstructure as well as a grain size smaller than 5 mu m while that from the former shows abnormal grain growth with sizes varying from 1.5 mu m up to 25 mu m. Vickers hardness measurements yield an average hardness of 7.4 GPa at 0.1 kg load for the samples derived from the wet-chemically derived precursor and 13 GPa at 0.1 kg load for the sintered samples from the commercial powder. The first value is characteristic of crystallites oriented along the (2 2 0) plane while the second value speaks for crystallites oriented along the (0 0 2) plane. (C) 2008 Elsevier B.V. All rights reserved.