Expert: Troy Thoreson - 5/9/2009

Question
I have a 1964 sealed proof set and on the back of the Kennedy half dollar there is a burn mark on the rim just to the right of the A in America, Also the nickel in the pack is discolored on the bottom left of the front and the top left of the back.
Any Ideas?
thanks

Answer
Hi Mike,

Many proof sets of the 1950's and early 1960's have toning.  The burn mark is a deep tone.  We have seen deep toning on these types of coins.  Currently, the proof set market is depressed in general.  Best to keep the set as is and what for a higher market or Silver value.  You may want to consider taking your set to a local coin shop.  Ask them to dip the half and to place the coins in a capital plastic holder.  They might charge you for this.  The holder will cost around $10.  DO NOT TRY cleaning the coins yourself - you will most certainly damage them.  My concern is that by not taking them to a dealer your coins will continue whatever chemical reaction is going on.  Over the very long term this can damage the surface.  Also, remember there is a change the surface of the half has been compromised by the toning - the coin may be already damaged.  Light toning is okay - some like it - deep dark toning (black in color) can be damaging.  

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.

Thanks for the question,

Troy Thoreson, aucpro.com