@Dave363 is correct, the coin is a large date 1982-D. Using his example pictures, see the difference in the shape of the "2".
Keep in mind OP .. the "rare" isn't just "rare", it's "super duper rare" as in only a few. You'll probably have to buy old coin collections that haven't seen the light of day to get one .. not just searching pocket change. http://www.numismaticnews.net/article/rare-1982-d-small-date-copper-found