My wife thinks every triangle shaped stone she finds is an arrowhead. She has actually spotted some pieces that are actually flint and on a very rare occasion one might be a piece of a broken chert that may or may not have been worked a little...but has NEVER found a real arrowhead.
So the other day we are out at the Little Woods and she gets all excited and picks up this slate stone that is kind of shaped like a bulky crude point and is almost 1/2" thick...but is not a point. She is positive it is an arrowhead and I tell her it is a piece of broken slate...she is having none of that and takes her prize home.