BACKGROUND: This study investigated the synthesis of magadiite from a natural diatomite material. The influence of key reaction parameters, including reaction time, temperature and molar ratios of Na2O/SiO2 and H2O/Na2O, on the formation of magadiite were investigated. The as-synthesized magadiite was characterized by X-ray powder diffraction, scanning electron microscopy, infrared spectroscopy, thermogravimetry and differential thermal analysis. RESULTS: The well crystallized magadiite with a rosette like morphology was prepared from a dispersion with the molar ratio H2O/Na2O = 28.15 and Na2O/SiO2 = 0.15 by heating at 160 degrees C for 42 h. The basal space of the synthesized magadiite is 15.5 angstrom and the stretching and bending frequencies of the SiO4 units making up the magadiite layer were recorded. The layered structure was destroyed when the temperature rose above 250 degrees C, and combining the results of thermogravimetry and differential thermal analysis suggested the structural alteration may be due to the condensation of silanol groups. CONCLUSION: Diatomite has been used to synthesize magadiite with a high purity and well crystallized. The cost of synthesis has been reduced allowing its use in conventional industrial applications, thus expanding the commercial utilization of diatomite. (C) 2009 Society of Chemical Industry