This paper reports on the synthesis of hexagonal plates of hematite, alpha-Fe2O3 crystals using microwave-hydrothermal (M-H) and conventional-hydrothermal (C-H) reactions. Platy alpha-Fe2O3 crystals which show dark red wine color were synthesized from 2M-FeCl3 and 8M-NaOH solution at both 140 and 180 degrees C and their morphology and crystal size were investigated. Average crystal size of hexagonal alpha-Fe2O3 was 0.9-1.6 mu m at 140 degrees C and 0.8-2.1 mu m at 180 degrees C under both M-H and C-H reactions. Compared to the formation of platy alpha-Fe2O3 crystals via C-H reaction, the M-H reaction led to increased rate of formation by 8 and 15 times at 140 and 180 degrees C, respectively. The M-H reaction yielded hexagonal plates of hematite in 2 min at 180 degrees C. The suspensions of platy alpha-Fe2O3 powders prepared at 140 and 180 degrees C by both C-H and M-H reactions showed dark red wine color due to similar crystal size and morphology, which have potential applications in cosmetic pigments, as anode materials in Li ion batteries. (C) 2017 Elsevier B.V. All rights reserved.