30 coins US Mint made to test designs, metals, expected to sell for more than $300,000

Thirty coins stamped by the U.S. Mint in the 19th century to test designs and metals are expected to sell at auction for more than $300,000.

The coins come from the collection of Dallas businessman and philanthropist Harry W. Bass Jr., who died in 1998 at age 71. Dallas-based Heritage Auctions will sell the coins individually Thursday at the American Numismatic Association's World's Fair of Money near Chicago.

The proceeds will go to the Harry W. Bass Jr. Foundation, which helps support organizations in areas such as education and the arts.

Heritage coin expert Mark Borckardt says the U.S. Mint sold the test coins in the 19th century, and they have been auctioned off in subsequent years.

The coins have been displayed at the American Numismatic Association's Colorado museum.