'A coin is generally going to be more valuable if it's higher grade,' McCartney says.Īnd take note: Experts advise against cleaning any coins you believe may be rare and want to sell. A grading of one means the coin is worn to the point of barely being recognizable, while a 70 means the coin is nearly perfect and looks like it was just created. Serious collectors want all of their coins to be authenticated and graded by a third party that has certified their value, McCartney says.Ĭoins are typically graded on a scale of one to 70. You should also send your coin to a rare coin authentication and grading company, such as Numismatic Guaranty Company or Professional Coin Grading Service, to be independently evaluated.
'In general, the internet has a lot of misinformation about coin prices,' he says. If you're lucky enough to find this rare penny or have another coin you think may be valuable, start by contacting a reputable coin dealer or auction firm rather than relying solely on information found on Google, McCartney says.