Survey of old records concerning the publication on mercury provides a very useful means to trace exhausted and forgotten mercury mines and thus complete the gaps in the distribution of mercury are deposits in the Japanese segments of the Circum-Pacific metallogenetic zone.
The discovery of a mercury mineral in 198 A. D. is described in “Shoku Nihonki”, the earliest literature referring to the Japanese mercury. The mining of the metal in record, however, dates as far back as the Asuka period (600 A. D.) and a peak production was once reached during the Heian period. In those early days, mercury was used principally for medicine, amalgam base for gold-gilding on Buddha statues, and ship paint. The mining was operated throughout Japan by the “Niu” tribe, an ethnic group which was once headed by “Niuzuhime” in Yoshino region and later spread out searching for new deposits. “Niu” means cinnabar and also red color in Chinese. For this reason, villages in former mercury-producing district often bear the name of Niu and have shrines called “Niu Jinja” which are dedicated to Niuzuhime.
It is also reported in literature that the search for mercury was also conducted by “Yamabushi”, a group of itinerant buddhist priest who travelled around the country carrying the will of Kobo-daishi, the famous founder of their sect.
Although the occurrence of mercury in “Hitachi” and “Dewa” districts was mentioned in ancient literature, no mercury deposits have been discovered geologically in recent years. The mercury contents of reddish clays from these localities, however, are high enough to be indicative of the presence of such are deposits.
