Michael N. writes: Why aren’t you supposed to clean your coins?/whats the way to do it without losing their value?
Generally, unless you are an expert an conservation techniques, you are more likely to ruin the coins than enhance their value by cleaning them.
Cleaning coins often removes or disturbs the surface of the coin. Since value so much depends on state of preservation, altering the surface of the coin tends to reduce its value. Cleaning the coin never raises the grade, i.e. you can’t make a coin with wear uncirculated again simply by polishing the surface. The term uncirculated has nothing to do with “shiny” or “bright”. Also see: I cleaned and polished tarnished coins – did I ruin them?