Mineralogical studies of bauxite (II)

Abstract

In the previous number of this Journal, the mineralogical studies of bauxites from the nine different localities were described. In that case, the X-ray photographs of the powdered bauxites and their burned materials were simply used for the recognition of the mineral varieties existing in the bauxites, whose refractive indices were already measured. In the present case, the distances of the diffraction lines were measured in order to determine the indices of the net planes corresponding to these lines, the results being given in Tabs. from 1 to 8. By these results we can see that the mineral varieties contained in the bauxites are the same as those determined by the optical method. From the characteristic combinations of the indices of the net planes the space groups of these minerals were determinable as Vh16 for diaspore, Vh17 for böhmite, C2h5 for gibbsite and D3d6 for a-Al2O3. The present studies were carried out under the cordial directions of Prof. S. Kôzu, to whom the author's genuine appreciations are due, and also he is gratiful to Ass. Prof. K. Takané for the helpful guidances.