Archie, you are changing the context in which the word was being used. They are using the word to describe the condition of an object, NOT how the object was manufactured.

There are many words in the English language that have more than one meaning or purpose. I do agree that you "mint" coins but not chips. But it is totally appropiate to use the word "mint" to describe ANY object as in like new condition.

In fact, the usage example that I saw was "the painting was in mint condition".

http://dictionary.reference.com/search?q=Mint