Owner Comments:
JNDA 01-10B/C.
10B refers to a gin marked coin of the larger diameter yen and 10C for the smaller. My two gin marked coins are not graded as they are harshly cleaned examples. This is an example of the left placed mark, indicating it was done in Osaka.
10B: Diameter 38.6 mm, 0.900 fine, 26.96 grams.
10C: Diameter 38.1 mm, 0.900 fine, 26.96 grams
—Gin marked coins—
The gin mark is a stamp with the character that literally means ‘gin’ or ‘silver’. The mark was placed on the reverse of the silver one yen coin either to the left or right of the denomination. Mark location was determined by which mint placed the mark (Osaka on the left, Tokyo to the right).
The JNDA gives a specific catalog number for the gin stamped coins. The diameter, weight, and silver content remain the same as the base coin. Coins that would otherwise be 01-10 (larger diameter yen) are now 01-10B, and the 01-10A (smaller diameter silver yen/same silver content) are designated 01-10C. Unlike chop marks, these mint applied marks are not considered ‘post mint damage’ and may only marginally affect the value to collectors (individual collector preferences may vary).
Japan was initially and nominally on the gold standard with the inception of the Meiji era modern yen based coinage, with the gold yen consisting of 1.5 grams of gold. The silver yen was adopted initially for trade but was subsequently used domestically as well. The government set the exchange rate between the two by decree given gold and silver supplies of the time. Over the years silver became the functional standard.
However, as silver became more plentiful, the value of the metal content in the silver one yen coin did not keep pace with the value of the gold, thus resulting in a large outflow of gold from the country as foreigners would trade cheap silver for gold.
In year 30 this disparity resulted in a new return to the gold standard by governmental decree. The gold yen was now reduced to .75 grams and silver yen were to be withdrawn from circulation over a designated period. (This new standard effectively doubled the value of the old style gold coins, while devaluing the silver). The silver coins were allowed to be exchanged back at the new, lower, gold yen standard through April in year 31.
The newly traded in silver yen coins were either melted or were sold to other nations as a functional trade dollar. To prevent the sold coins from being returned and traded back multiple times the coins were stamped with the ‘gin’ mark to indicate they were previously exchanged.
Interestingly the silver one yen coin was brought back and minted starting in Meiji year 34 but purely for non-domestic usage so no ‘gin’ mark would be placed on a coin from M34 on. The silver yen coin remained demonetized domestically. And, despite ‘one yen of gold’ being standardized, no coin was made with the new weight standard (perhaps due to technical challenges of such a small coin, but I speculate).