The collecting of coins is known as numismatics.
While the term numismatics can refer more broadly to the study of money and currencies including paper money and medals, in common usage, it is often used interchangeably with coin collecting.
A person who collects or studies coins is called a numismatist.
What is slang for coin collector?
I can help with that. Other forms: numismatists. The person who looks closely at every penny might not be cheap — he might be a numismatist, a coin collector, looking for old or rare coins that somehow got into the mix.
What is another word for coin collection?
Great question! The name that we give to the collection of coins today is numismatics, a word that also encompasses the collection of paper money and of medals.