Very strange, how strongly does it stick to your magnet? I know that the Chinese sometimes counterfeit modern US coins, like the Sacagawea dollars for example which are widely circulated in South America. As I recall, something like 60% of the US dollar coins circulating in Colombia are fakes, and I wonder if smaller denominations are faked as well.
Since the coins is of no real value would you be willing to file away at the edge to see if it is clad with a proper copper core? If it's solid ferrous metal it should be pretty obvious and very interesting.