What makes you think it's fake? Anything physical about the coin, or are you just surprised you got it in a job lot for not much money? Although the aphorism 'if it looks too good to be true, it probably is' holds good in 999,999 out of a million cases, there is the occasional exception (like the German Kiautschau coin I got in a job lot of garbage that turned out to be worth £25-ish for the princely outlay of under 10p).