Cleaning Coins: Should I or Shouldn't I Do It?

People who join the ranks of numismatists often ask the question, ‘how do I clean my coins?’ It is normal to think that a shiny and clean coin will be appealing to coin collectors and appraisers, thinking that cleaning it will increase its value. The truth is, coin collectors would rather get a coin displaying its natural and original color.

If a coin manages to stay bright and shiny because of preservation methods or just released from the mint, collectors would gladly purchase it. A coin cleaned with baking soda, vinegar or abrasives would give them several reasons to hold off on the purchase.

Experts Know When a Coin Has Been Cleaned
Collectors prefer a deep, brown coloured coin that is more than five decades old than a similar coin cleaned to look brand new. Here are signs that indicate a coin has been cleaned:

1. It has an unnatural colour
2. Streaks or blotches of colour
3. An unnatural uniform colour
4. An unnatural and uniform reflectivity

You will not be unable to fool a true collector, if they detect any of these signs on the coins you plan on giving or selling to them.

Determining Value: Cleaned Vs. Un-cleaned Coins
There is not much science involved in determining the value of a cleaned coin. Many factors of value follow an ‘eye appeal’ and how ‘good’ it looks. But a coin loses some of its value after you clean it.

1. A coin that has underwent abrasive cleaning that it now has hairlines, scratches and has lost its former lustre is no longer worth anything more than half its un-cleaned value.
2. A lightly cleaned coin and does not have scratches or shows little to no signs of loss of lustre, may drop in value by as little as 10% or as high as 30%.

There is no clear-cut rule to determining the value of a coin as the price of a cleaned coin is done on a case-to-case basis.

Are there safe ways to clean a coin?
There are a few instances where cleaning a coin is recommendable. One such case is when it is encrusted in dirt, the best way to clean this is by using clean water. Pat the coin until it dries instead of rubbing it.

Problems about cleaning a coin arise when a person attempts to, whether deliberately or not, remove the natural patina or colour that a coin has taken on over time. Rubbing a coin leaves scratches and lines on its surface, reducing the coin value.