Sorry to bother you @JCro57 but I cannot find the post where you guys were discussing these nickels and what the qualifiers were for genuine sintered planchets. What does your experience say about this coin?
No bother at all... Annealing is a process where coin blanks are heated in an oven before they are struck by the dies. This is done to soften the metal, which actually also helps strengthen the metal. If this process is bypassed, a coin blank remains brittle and could possibly crack, split apart, or even sort of shatter when great pressure is applied from the force of the die-striking process. If left in the annealing oven too long, silver-colored coins that are copper-based (for example, nickels are 75% copper, and clad coins have a copper core and are also plated with a copper-nickel alloy) can sometimes result in copper atoms shifting to the surface which makes them now a rusty-looking copper color, or can be dark like a grey or black, or even pink, brown, or can appear spotted - even only affected on one side. Some felt this was due to copper dust leftover in the annealing oven left from previous batches of coins, which then settled on other coins (sintered actually means going from powder right to a solid without liquidation). These were once called "sintered" or "copper wash" coins. When ejected from the striking chamber, the edges rub the collar (much more so if a coin has reeded edges) on the way out. Thus, edges should appear with a silver color instead of the deep red or grey/black. I have seen many coins at shows where dealers are selling these as improperly annealed, but almost every single one that I've seen is really just a damaged coin, and many of these are just environmentally damaged from the elements. Unfortunately, it is my opinion that your coin actually looks like it has environmental damage.
Looks like a copper wash .... ie, when I have really dirty coins, instead of throwing them away due to the muck, I'll throw cents, nickels, dimes etc into a mauratic acid wash. The nickels, dimes, quarters although much cleaner have an inconsistent copper wash over them as they just a small pile of change thrown in there. Of course, I then use the money. I'm sure I'm not the only person that cleans coins using some form of acid. There's a couple threads here where I show some that were cleaned with copper wash on them.
Thanks! I couldn't remember the rules for the edge of the nickels. Then the annealing process is done to the planchets after they are cut from the strips. So the coppery discoloration can be "rubbed" off? If so, then what you are saying is the discoloration of a black beauty is only "skin deep". Therefore it would be possible to find one well circulated that has the silver colored nickel showing through worn spots?
Not 'copper wash' imo. Looks like, as mentioned by Joe, enviornmental damage on the surfaces - stained, by any other name.
I have never actually tried to "rub" the copper coating off should the copper particles surface on a nickel or other coin. I know it can get thick enough to form a shell and even flake off, and even come apart in entire sections. For some reason, Sacagawea and Presidential dollars only go to a deep grey; I have never seen a reddish-copper on the surface from those coins when over annealed. I guess it would depend at what stage the copper on the surface has ingrained and is now fused on to the surface layer of it to be able to actually rub it or buff it out. As to exactly why some only turn grey/black while others become a rusty-red, why some appear on the entire surface while others have spots or streaks, why some only have red on one side, etc., is something I really do not understand.