Colloidal dispersion of oxide nanosheets was prepared by exfoliation of lepidocrocite-type layered titanate H1.01Ti1.73O4, and the obtained "nanosheet colloid" formed a liquid crystalline phase which was detected by birefringence of the colloid with naked-eye and optical microscope observations between crossed polarizers. The nanosheet colloids exhibited phase transition from isotropic to isotropic-liquid crystalline biphasic, and finally to full liquid crystalline, as the nanosheet concentration increased. The mesophase was characterized by the stability; liquid crystallinity appeared at low particle concentrations due to high aspect ratio (around 1 tun of thickness and similar to 7 mu m of lateral length) of the nanosheets. Mixing the titanate nanosheet colloid with hectorite clay yielded apparently homogeneous birefringent colloids, where a cationic cyanine dye was selectively adsorbed onto the clay nanosheets. (c) 2005 Elsevier B.V. All rights reserved.