How to tell die crack from similar PMD?

A die crack is an open line in the die. When a coin is stamped metal flows into the crack thus causing a raised (relief) line on the coin.
Same with "cuds" where part of the die has broken off.

PMD usually removes metal or, sometimes shifts it around (so some could be raised but it has come from somewhere else on the coin, which will be incused [below the surface]).
The only PMD that I could think of to give a raised surface would be where someone attacks it with a welder or gas torch and melts metal onto the surface. I haven't come across this but would not be surprised).

Jeff

Same as trying to identify the difference between surface scratches (cleaning damage) and die polish lines. Sometimes it's very difficult to tell and even harder when you haven't got the coin in hand. Scratches are incuse and die polish is raised. Scratches are bad, die polish is good.

30x should be plenty! What works sometimes is using a strong light and tilting the coin face so that in some angles you can see shadows from the detail. If there is a shadow from the line it is propably a crach. If there isnt then it is probably PMD.

Jeff, you wrote one of the best and clearest definitions for a die crack! Thanks
Appleangel, great photo's. the naked eye can be deceived.