CHOPMARKED COINS: JAPAN: Meiji, 1868-1912, AR yen, year 29 (1896), Y-28a.2, JNDA-1-10C, with gin countermark left for Osaka mint, with two Chinese merchant chopmarkd, EF. In October, 1897 Japan revalued the gold yen, and changed from a combination silver/gold standard to an exclusively gold standard. For the next six months the silver yen were exchangeable for gold. Part of the demonetized silver coins were melted for use in minting subsidiary coins, and the rest were shipped to Taiwan for use as bullion silver. Before being exported, they were countermarked with the character for silver (gin), in a circle, to prevent them from being returned to Japan for another shot at exchange for gold. The gin countermark appears in a specific position - to the left or right of the ichi (one) character on the reverse. Krause states as a fact (which many Japanese authorities are less certain about) that the main Mint at Osaka applied the mark on the left side, and the subsidiary Tokyo Mint applied it to the right.
Estimate: USD 75 - 100