This is the story of a guy who cleaned a coin that was valued at $250,000 and it is now worth just about $10,000 or less. By cleaning the coin the man changed the surface texture to the incorrect mirror-finish (and the destruction of detail that causes) was the reason of the drop in value. This is why you never, ever, should polish or attempt to restore a coin to ?improve? it.
Guy Ruins a $250,000 Coin by Cleaning it
Video by coinweek