Finally got a nice variety of these to share, at a price that only has me eating Ramen and beans for the next month!
Information on these coins (in English) is pretty scarce, but here is what I was able to piece together.
Mameita gin (roughly translated as bean silver) was a currency used in Japan, initially to bridge the gap between the extremely low value Mon and the massive silver chogin ingot, and also to adjust for irregularities in the weight and purity of the chogin.
I am not sure exactly how they would have been useful as currency, as silver purity ranged from about .800 to .150 or less. Size also varied wildly, but most are about "bean" size in terms of diameter and thickness. Exceptionally well struck pieces were apparently meant as gifts or presentation pieces to nobility or prestigious Samurai.
The designs are a bit hard to figure out, but most depict a very abstract image of Daikoku, the god of wealth. Alternate images include various characters, indicating era, or the character for "silver". They were hammered into the cooling silver, and may be complete, or barely present. The reverse may be struck (generally in the abovementioned presentation pieces) or it may be coarse from the process of dripping the molten silver.
Mameita gin were made from the 16th or 17th century (the earliest certifiable examples date to about 1620) and stretch to the 1850s, although they were largely replaced by the shu gin bars in the early 1800s.
Anyway, here are mine:
From the large one at the top, going clockwise:
- Genbun era (1736), 11.8g, .460 silver
- Shotoku era (1711), 3.4g, .800 silver
- ? era, tiny mameita gin called a "rogin", 1.3g, unknown purity
- Kyoho era (1714), 4.8g, .800 silver
- Tenpo era (1837), 6.8g, .261 silver
And to illustrate how small these are:
If you have any to share or any additional info, please feel free to chime in!