本邦産マンガン硼酸塩鉱物

抄録

Four manganese borate minerals, jimboite, wiserite, sussexite, and Mineral X of Epprecht et al. (1959) have been found in seventeen bedded manganese ore deposits in Japan. Their principal mineralogical properties and mineral associations are given to present their diagnostic features and the characteristics of manganese ores comprising them. The manganese borates occur as layers conformable with bedded textures of ores, minute veinlets cutting them, or minor interstitial bodies among associated minerals. Ore minerals associated with them include rhodochrosite, jacobsite, sonolite (or alleghanyite), alabandite, jacobsite, galaxite, hausmannite, tephroite and gageite, these being characteristic in low silica and higher grade manganese ores. The occurrences suggest the simultaneous concentration of boron with manganese, these elements being considered to have been released from basic magma after the reaction with sea water.