Genho Tsuho (元豊通寶), Nagasaki Trade Coin, 24mm, extra dot found on the upper stroke of ‘元’, single dot ‘通’, covered by reddish to black corrosion layer. The patina layer on this Genho coin looks different in color than Chinese coin. A RARE specimen. “元豊通寶”，日本長崎貿易銭，万治2年（1659）單點通， 多點元；日本為了與中國貿易，特地仿製中國錢幣，銅材較差，混進錢堆中與中國交易。 與北宋元豐通寶最明顯的區別點在於豐字，日本貿易錢是「曲頭豐」。