An incredibly rare glass coin was featured during Heritage's public auction held on January 6, 2017 in Fort Lauderdale, Florida. Manufactured in 1942, as a possible alternative to copper that was desperately needed during World War II, this only known surviving all-glass penny was realized for $70,500.

During a war between a phone bidder and a floor bidder, the cent's selling price doubled its $30,000 expected value. The historic glass penny was finally won by an American collector bidding on the phone.

“This one-of-a-kind cent is a part of U.S. history. Collectors love to own unusual specimens, and although glass failed as a substitute for U.S. coinage, this piece represents a unique artifact of the ingenuity and determination of U.S. Mint officials and private industry," said Mark Borckardt, Senior Numismatist at Heritage Auctions.

The example offered is made of tempered, yellow-amber transparent glass by the Blue Ridge Glass Company of Kingsport, Tennessee. It is the only surviving example of two coins know to exist, the other example is broken in half.

After considering countless alternatives – including glass, plastic, and rubber – the U.S. Mint eventually settled with zinc-coated steel in 1943. When the experimental glass cents were completed in December 1942, it was too late for the U.S. Mint to consider glass as a viable replacement for the penny.

The glass penny was just one of many highlights to Heritage's $65 million series of auctions held throughout the week of January 1-6.