QUOTE(henare @ Apr 26 2008, 12:06 AM)

i suspect what happens is that someone who specializes in this stuff (someone who knows the details very well) sees a new specimen and feels like it just "doesn't look right" ... and then they engage in a more careful examination until they find the difference.
You know what's funny, I told my friend I got into numismatics and he said he had some coins he'd put aside. He didn't know anything about how after 1964 they used less silver in most coins or anything like that...of the 15 or so coins he had they were all minted before 1965 or were half/dollar coins. I asked him how he knew to pick these out he replied "they just didn't look right".