1957 D Penny With Something Going On With Liberty

It looks like it has taken a hit displacing the metal, PMD.

Shane, there are limited things that can cause an error as it has to happen during the striking
of the coin but there are countless things that can cause damage after it has been struck.
Anytime you have dings, scratches, discolouration, bent or flattened letters etc.
these are usually just damage.
Learning the minting process is a big step in identifying errors.
By looking at a coin, ask yourself if it is possible to have happened in the striking chamber,
If not, no matter how it happens then it is damage.
A good source of identifying real errors is go to error-ref.com

Thank you both so much. Why I never thought about learning the minting process in order to find errors I'll never know. Thank you for that suggestion and I'll check out the link. Thanks again. By the way I have a few coins that I would like graded. What is a good formula for figuring out cost vs potential return? Is there a percentage you look for?

Yes, a classic 'BIE' die chip.

Thinking of having coins graded? There is no common 'formula' to determine return-on-investment for graded coins. The human factor comes into play and that tends to unravel the math. Thorough research of what graded coins the same as yours have sold for (Ebay, other auctions, etc.) would be worthwhile. TPG grading fees are pretty well known--sale prices, however, can be fairly volatile. Suggest you post a few of your coins on separate threads for grading opinions.