I don't have a picture right now, but I figure you guys have seen this enough to be able to discuss it without one. I know that normal 1999 nickels are part copper. Since there are no lines or raised edges outlining the places with copper, I was thinking it was an error in the alloy process, rather than a striking error. Also, the copper appears on the obverse, reverse, and edges. Any thoughts/threads about this?
Really need a photo, but in the mean time, there is a very intriguing article by an expert Mike Diamond who is a member here also, in Coin World 11/30/09 pg. 124 called "Unknown annealing drum problem cause of discoloration". He mentions some examples that are extremely confusing but interesting from the metallurgy and physical chemistry viewpoint ( at least to me). Copper discoloration is the primary one discussed. Jim
