Shiny Again: How to Clean a Penny Using an Eraser #CoinCollector Using an eraser to clean a penny works because the eraser's mild abrasiveness removes dirt and oxidation from the coin's surface, making it look shiny and new. However, for coin collectors, this method can be damaging. Cleaning a coin can reduce its value by stripping away its natural patina and causing tiny scratches, which can detract from its historical and aesthetic appeal. Collectors prefer coins in their original, unaltered s