In this paper, the authors studied the mineral composition of a phosphorite deposit in southern China. The physical measurements, such as the specific density, hardness, optical property, differential thermal analysis and powder X-ray diffraction of the apatites are carried out. Furthermore, the chemical analysis, the phosphorus availability analysis and the suspension pH value are also given.The microscopic observation exposed four types of crystal form of apatites, i. e. optical amorphous, cryptocrystalline, fibrous crystal aggregation and crystalline. Accordingly, it is suggested that they have been formed or transformed in five generation. In consideration of their physical properties, nature of crystal optics, crystal structure and chemical composition these apatites may be regarded as one member of the isomorphic succession between fluor-apatite and the francolite.The correlation of the physical and chemical properties of apatites are analyzed by the method of regression. It is shown that the refractive indexes of apatite are increased with the increase of value a0, ratio F/CaO and P2O5/CaO, and decreased with the increase of ratio CO2/CaO. The value a0, moreover, is increased with the increase of ratio P2O5/CaO and decreased with the increase of ratio CO2/CaO. By the R-model cluster analysis, various physical and chemical parameters of apatites may be divided into two groups: "parameter group effected by acid-alkalinity" and "parameter group effected by concentration of phosphorus". In the case of increase of pH the carbon would easily enter into the crystal lattice, as a result, the value a0 would be decreased, while the ratio CO3/CaO and C0/a0, as well as the phosphorus availability would be increased. In addition, in the case of greater concentration of phosphorus the entrance of carbon into lattice seems to be more difficult. Thus, the value a0 and refractive index would be relatively higher.Based on the investigation of the succession of apatites and associated minerals, their postsedimentary alternation and paragenie relation may be distinguished as five types of mineral association with different mineral association, chemical composition, content of P2O5 and availability of phosphorus. They are: 1. apatite-psammitie quartz-silica-clay shale fragments association; 2. apatite-silt quartz-glauconite association; 3. apatite-hydromica association; 4. apatite-limonite association and 5. apatite-dolomite association.
. 1975, 我国南方一磷矿床磷块岩的矿物组成. 地质科学, 10(2): 114-131.
. THE MINERAL COMPOSITION OF A PHOSPHORITE DEPOSIT IN SOUTHERN CHINA[J]. Chinese Journal of Geology, 1975, 10(2): 114-131.