You might want to check and see what they are selling on ebay for. It sounds like they might be the 1 centavo coins, because they are about the size of a US quarter and are made of bronze. If they are the 20 centavos coins, then Rdwarrior is right, and they are made of .750 silver from 1907 and up. If they are before 1907 they are .900 fine, same as in the US.


















