On the viridine quartz schist from the Chisaka Area, Hidaka Province, Hokkaido

Abstract

In the paper, the mode of occurrence as well as the petrological and chemical properties of specially interesting viridine quartz schists which were discovered from the Chisaka area, Hidaka Province, are described. Viridine (the mineral is sometimes identifies as manganand-alusite) is generally very rare mineral and has been reported from only seven localities in the world, since it was first noticed in 1889 from S. Sweden. Subsequently the viridine from Chisaka is the first example to be known not only Japan but in E. and S. Asia. To summerize from the geological and petrological points of view, the rock may originated from high siliceous and argillaceous sedimentary rock containing a moderate amount of manganese and iron, under medium-grade regional metamorphic condition.