Dolar perdagangan itu apa sih? Jelaskan dalam bahasa melayu ya

Dolar perdagangan ialah duit syiling perdagangan yang dikeluarkan oleh berbagai-bagai negara.

The United States Trade Dollar is a silver dollar coin that was issued by the United States Mint and minted in Philadelphia, Pennsylvania, Carson City, and San Francisco from 1873 to 1885. Business strikes ended in 1878.

The coin was designed by William Barber, the mint's chief engraver. More trade dollars were minted in San Francisco than Carson City and Philadelphia combined. San Francisco was closest both to the source of the silver as well as the ultimate destination of the coins, China. Many Trade Dollars have what are called "chop marks" on them. The Chinese merchants would stamp the coins as a way to check their authenticity and to add their advertising logo.

The United States Congress authorized the U.S. Mint to create a trade dollar to improve trade with the Orient, China in particular.  Prior to that, the Mexican peso had been the primary silver coin used in trading with China.  In fact, the eagle on the trade dollar's reverse looks quite similar to the peso's.   The coin was minted at 420 grains (27 g) of silver with a fineness of .900 (90 %), about 8 grains (520 mg) more than the domestic silver dollar of the time, and 4 more than the peso.  However, the peso was .903 silver.

Collectors are warned that recently a large number of U.S. trade dollars, of various quality have been made in China.  Purchasing from known dealers or buying sealed and certified coins may be necessary to avoid these fakes.