I got a roll of quarters for the laundry here on campus, and when I was looking through them, I found a 1965 with no mint marking, and a 1990 D. The 1990 looks better than the 1990 S's that were in the same roll, did Denver only make proofs? It looks way cleaner, more detailed, etc, than a S, especially for a 18 year old coin. Also, did the 1965 have any silver in them at all? Sorry for the questions, I'm fairly new at coins and don't know too much about them.