60 réis countermarked silver coin
Original coin of Sebastian's reign, later countermark ・ silver ・ 17th century ・ Kingdom of Portugal
The original is a half-tostão of Sebastian's reign. Years later the numeral "60" was punched onto its face, and it passed as sixty réis. Not a debasement in disguise, but a new value openly stamped over an old coin: the countermark is an honest revaluation, hiding nothing of the fact that a coin's worth is set by decree, not by metal.