Expert: Troy Thoreson - 6/19/2009

Question
Hi, I have a question about coin colors. I understand that red is generaly the most desirable color, however I have noticed that of 500+ copper pennies I've been hoarding, some of the older pennies that have lost their luster have not lost their color. 95% or so of the old pennies are that muggy brown color, but a couple of my pennies, and one in particular, is quite red in comparison to the other pennies. I don't quite know what it is that makes it appear so much redder, but i'd like to know if it was a chemical thing or an impurity difference that caused the coin to appear differnt as it aged, or if I'm just crazy. I'll include a photo, its quite easy to tell in pictures. the one picture has the coin in question in the middle, and a standard "red" colored coin below it along with other pennies, the other has hte red one in the middle again with a brown penny on the left and a relatively clean but faded penny on the right. (http://www.flickr.com/photos/14070575@N08/3639883987/)

Answer
Hi Paul,

You are not crazy.  No U.S. cent is 100% copper.  There is always some other alloy used to bring up the balance.  Modern examples are mostly zinc.  Sulfur plays a role in the shade of Red you will experience, plus many other factors.  Some people spend a life time trying to get all coins the same color red.  I have heard other say that all Uncirculated Cents will be brown at some point in the future.  So the trend is always Red to Brown.  Granted it make take a 1000 years, but eventually all your Cents will most likely turn brown over time.  

Please remember to never clean coins, this can damage and lessen their value.  Also, soft plastics can contain harmful chemicals that can react with coins over time.  Try using inert materials when storing coins.  Plus, it is always a good idea to store coins in a safe.  The safe should not be exposed to the elements and should not be up against a wall to the outside.  These are just a few tips I have learned over the years to help keep your collection in top shape.

If you found this information helpful please nominate me for category expert in coins.  If coming through Los Banos, CA please feel free to look us up at Thoreson Numismatics, 947 6th Street, Los Banos, CA  93635.  209-826-0777.   Please remember that we are always in the market to buy and sell coins, currency, tokens, and medals both U.S. and World.  We are also licensed to buy scrap gold & platinum jewelry.  

Thanks for the question,

Troy Thoreson, aucpro.com