Good afternoon! I have a 2011-D Washington quarter and abit1979- D SBA dollar coin that have the similar color/toning. Just want to get some info on what may have caused this discoloration. Is this due to corrosion, scrubbing, wear from circulation? Oddly, I do like how it adds drama to the design on both coins in this condition especially the reverse. Appreciate any comments and or info. Thanks
Is the edge of the coin also discolored or does it look shiny and new. If it looks shiny it's improperly annealed.
Here's a pretty good explanation. http://www.coin-rare.com/mississippi-state-quarter-mint-error-coin-ms66.aspx
I think you need to read it again - The underlining and the bold text are my doing. The key word there is "some". In other words, while some improperly annealed coins may have a "shiny" edge - not all of them do. Thus the shiny edge is not a valid diagnostic. In order to be a valid diagnostic they would ALL have to have shiny edges.
This is referring to how the planchet was laying in the annealing drum when it dried. You must not have read this part. "See the edge photo (#3) - it looks like a normal BU Quarter - the copper core shows a nice normal red color - that's because although the planchet itself (on a genuine mis-annealed planchet) would have the dark color on the smooth edge, once it's struck in the collar, and ejected, that dark color is removed from the reeding due to the ejection of the now-coin from the collar."
All I am saying that just because a dark coin has a shiny edge, that does not mean it is or was an improperly annealed coin. Is it possible that an improperly annealed coin could have a shiny edge ? Yes, it's possible. But not all improperly annealed coins have a shiny edge, and that includes reeded coins. Things that might be true are not valid diagnostics. Things that are always true are valid diagnostics. But don't take my word for it - ask Fred.