Hi there, I came across this fella a little while ago. I'm guessing that it is either Chinese or Japanese, but I honestly do not know. It is 22 mm across, and weighs in at 3.57 grams. Thanks in advance
It's a Chinese cash coin from the Qing (Ch'ing) Dynasty. The coin should be rotated 90 degrees counter-clockwise to be viewed correctly. The inscription on the obverse side reads qian long tong bao which means it was cast during the reign (1736-1795) of Emperor Gao Zong. The reverse side indicates that the coin was cast at the Board of Revenue mint in Peking (Beijing). This coin would be considered "very common". Gary