A Long Spacing at about 30 kX. confirmed from a Fireclay

Abstract

THE white clay from the Kurata Mine, Yamaguchi Prefecture, Japan, is largely composed of kaolinite; in flinty massive specimens it is commonly well crystallized, whereas in powdery massive specimens it is disordered. The clear resolution of the (11&1bar;), (1&1bar;&1bar;) doublet is revealed in X-ray powder reflexions of a certain flinty specimen. The disordered behaviour is marked by a band of the two-dimensional type associated with (020). These facts were first reported by G. W. Brindley and K. Robinson for specimens from England. It is noteworthy in the present case that reflexions from the latter type are frequently accompanied by those of montmorillonite as well as a clear powder reflexion at 29.8 (± 0.5) kX. The basal reflexions of the montmorillonite are 14.7 (± 0.2) kX. (001), 4.93 kX. (003) and 2.97 kX. (005), and of the kaolinite, 7.13₈ kX. (001), 3.58 kX. (002) and 2.40 kX. (003). The intensity of the 14.7 line is commonly proportional to that of the 29.8 kX. line; but the ratio of the intensity of the kaolinite line to that of montmorillonite varies from specimen to specimen. The (060) spacing is 1.491₉ kX., which suggests that the amount of aluminium replacing silicon is small.