Definition: A chop mark is a Chinese character that has been stamped into a coin by a Chinese merchant who authenticated the coin's weight and purity. These are most commonly found on United States Trade dollars that were sent to China to facilitate trade. When the coin arrived in a Chinese port, the merchant would "chop" the coin with his unique Chinese character that identified him to other merchants.
As the coin was used in commerce throughout China, additional merchants would add their unique chop mark. Chop marks vary in size and shape. Some coins have only one chop mark on it, while other coins have so many chop marks that it would be considered mutilated. Some coin collectors consider chop marked coins as damaged. Other collectors consider this part of the coins unique history. Third-party grading services such as Professional Coin Grading Service, will authenticate and grade chop marked coins but will note that they are chopped marked in the coins description.
Alternate Spellings: chopmark, chop-mark
Examples: This 1875-S Trade Dollar has a Chinese chop mark on Lady Liberty's arm.