Didn't the Romans mix some garbage in to gold coins, thus causing massive inflation? This is an insane. http://www.msnbc.msn.com/id/24491928/?GT1=43001
Changing the composition of US coins is nothing new. The silver was removed from US coins way back in 1965. Steel was used to make the one cent coin for the full year of 1943.
greddy, the Romans did not use a fiat currency the way we do in modern times. The US Mint could make pennies and quarters out of cheese if they wanted to, without debasing our currency. Hell, that's how we have paper money right now. It doesn't cost more than pennies on the dollar to print a bill worth $100.