A piece of copper that was struck by the U.S. Mint in Philadelphia in 1794 and was a prototype for the fledgling nation’s money will go up for auction Friday. Businessman and Texas Rangers co-chairman Bob Simpson owns the item, which is known as the “No Stars Flowing Hair Dollar.” While it closely resembles silver dollars that were later minted in Philadelphia, it gets its name because it is missing stars. “While subsequent dollar coins struck featuring stars were added to the front of the coin, starless coins are considered by collectors and institutions as one-of-a-kind prototypes for the silver examples that would follow,” said Jacob Lipson of Heritage Auctions. Heritage Auctions estimates the prototype will sell for between $350,000 and $500,000 when it goes on the block online in Dallas on Friday. Known as a pattern, the front features the flowing hair portrait of Liberty and the date 1794, …