NEW YORK (CNNMoney.com) -- The U.S. Mint has implemented a rule against melting down pennies and nickels which, at current metal prices, could be worth more as metal than as currency.

The Mint has received numerous questions over the past several months regarding the metal value of the coins and the legality of melting them.

The U.S. nickel

"We are taking this action because the nation needs its coinage for commerce," said Director Ed Moy in a statement.

"We don't want to see our pennies and nickels melted down so a few individuals can take advantage of the American taxpayer. Replacing these coins would be an enormous cost to taxpayers."

The new regulations authorize a fine of up to $10,000, or imprisonment of up to five years, or both, against violators.

The rule also bans the exportation of the coins, beyond traveling with $5 worth and shipping up to $100 for legitimate purposes.

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