I am new to the concept of mint marks and have a vague idea what to look for. What I have been doing is a many coins an finding a baseline for what is normal. Then I look through piles of change to find variations. recently I came across a 1970 Dime with a Denver mind mark. What is odd about the coin is the D is almost resting on top of the 7 in 1970. What does this mean? is it of any significance? Jon Chrisemer
The mint mark used to be added to dies by hand with means of a punch. It wasn't unusual for these to miss the proper location. Mint marks far off the mark make an interesting collection but they generally don't command significant, if any, premiums. Sometimes these are punched twice or more and might even use different punches and these are very highly sought.