I have the same type of coin but is so thin it is just a front & back coin & both sides exactly match other nickels. 1964 no mint mark, lettering looks frosted over with silver looking coating or looks like it snowed silver on both sides & some hard to read. Jefferson & Building both are there in full but look odd on a thin coin so if anyone thinks this as special error or what do you call a coin like this? Photo,s yes but someone say something 1st so to make it worth the effort as I seem to have some nice found error coins ect but to find worthless? Thanks, Steven