Object To investigate the properties of layer crystal structure and its interlayer absorption and expansibility in montmorillonits clay lattice, which provide a basis for the montmorillonite as medicine adjuvant.Methods Montmorillonite sample was separated and purified from clay minerals, and the diameter of particle was less than 1 ?m in colloid, the setting film sample was ready-made, and the samples were analyzed with X-ray diffraction.Results The information of interlayer change pattern on montmori-llonite clay was obtained with different conditions.Conclusion Montmorillonite as swelling and adsorption clay minerals and form an interlayer absorption is possible and the X-ray diffraction can determine the amounts of layer distance.

Object The mineralogical and chemical compositions of the natural pharmaceutical montmorillonite clay were analysed with the aim of approaching the material base of its action Methods The means of X ray diffraction (SRD) and X ray fluorescence (SRF) were used for the quantitative analysis of the mineralogical and chemical compositions of the montmorillonite clay samples Results The essential mineralogical and chemical compositions of the six samples were obtained Conclusion Though there is some difference in mineralogical composition of the montmorillonite clay samples from different deposits, the average percentage of montmorillonite content in samples is 86%, and the chemical compositions of six samples are nearly similar