Brazil PCGS 1970 10 centavos struck on a 3.13 gram U.S. Lincoln cent planchet. The coin is copper, but has small pieces of "nickel" like metal struck into the obverse and reverse. This is common on off-metals to have minor or large amounts of the normal coin design's metal being struck into the "off-metal" planchet. This is perhaps something to do with the "different" type of metal causing metal that has "stuck" to the dies from their normal work of striking coins, "coming off" onto the surfaces of a planchet of a different metal.
Note: PCGS did not note this as being a U.S. cent planchet, but we firmly believe it is since off-metals for country on U.S. cent planchets are known, and the weight and metal are correct for a U.S. cent.