ON THE MICRO-STRUCTURE OF JAPANESE MAGNETIC IRON SANDS (1)

Abstract

Japanese magnetic iron sands are mainly composed of ilmenite, magnetite, hematite and their coexisting grains. Variable contents of essential oxides are summarised and the leading limitations with respect to their origin, basic and acid, are defined. They give a concrete review of their study on the physical and chemical properties of this sands and discuss the relation between microstructure and magnetism, reducibility and oxidation by gases.
Regular intergrowths in the systems of ilmenitemagnetite and ilmenite-hematite are studied microscopically under the ordinary and polarized reflected light; their orientation and identi-fication of minutely intergrown are also described. Some grains represent the solid solution between them. 5 tables., 4 text-figures and 24 microphotographs are given.