Chop marks on coins

Chop marks on coins are Chinese characters stamped onto coins by merchants in order to validate the weight, authenticity and silver content of the coin.

Starting with the 18th century, a number of European, American and Japanese silver coins (generically known as the trade dollar) began circulating in the Far East. Each merchant's firm had its own mark and, after heavy circulation, the design of the coin became completely obliterated by the chop marks.

The practice lasted until China demonetized the silver coins in 1933.