On April 17, 2007, a Department of the Treasury regulation went into effect prohibiting the treatment, melting, or mass export of pennies and nickels . Exceptions were allowed for numismatists , jewelry makers, and normal tourism demands.  The reason given was that the price of copper was rising to the point where these coins could be melted for their metal content.  In 1969, a similar law regarding silver coinage was repealed. Because their silver content frequently exceeds collector value, silver coins are often sold by multiplying their "face value" times a benchmark price that floats relative to the spot silver price per ounce.  According to US law, US citizens are allowed to melt foreign coinage (. Canadian pennies) for personal or commercial use.