Sintered/Annealed 50ct Coin? Showing Copper Surface?

Thanks trout, do you think it could be a Piebald pattern annealed error? shiny nickel, shiny copper & a little brown? I am sure a Piebald pattern is still an improper annealed coin!

ok, does anyone have a similar picture of this type of coin?(my coin). I would like to compare photos? .If a blank was over heated in an annealing oven, doesn't some of the copper separate to the top? cheers.That's how it looks to me!

sorry trout It is no pub coin not by a long shot. The coin is not corroded either. The thread all wrong! Not a pub coin or road kill or found in a park! I still have no viable or plausible answers? To shiny, non corroded and not damaged in a Mechanical sense, it looks way to organic to be tampered with to. I see green patina, nickel & shiny copper all through the heads side! There is something else to this coin. Can someone please think of a more plausible answer other than Pub coins, or buried in earth dirt. Floating separated nickel & copper due to extreme heat in oven. That looks more like the picture of the coin. Cheers peoples.

Regardless of the outcome, Moneybags, thank you for this thread. I just read through the entire thread that your first post referred to, and found it extremely absorbing! Keep asking, Keep questioning, and by all means, Keep posting :)

Good Morning, thanks to you all who answered my post. I just got a little frustrated with no real detailed answer. I wont clean up the coin until I can show it to a Dealer one day hand to eye, to get a clear point of view on it.
Mr trout man, We would love to see your coin if you could make it if it is possible. Cheers in kind to all.

The 50c looks like PMD to me, although it may have been caused naturally.
Over the years, I have seen a few copper nickel coins, of all countries, that quite obviously look to be copper, but in fact, are not.

An aggressive environment can cause this over a period of years, which would also require to coin to be out of circulation to allow the coin to change appearance, especially if the change was happening in natural circumstances.

Differential 'toning' such as this could occur if the coins were heaped, not stacked.

I also see the possibility of a 'pub coin', to fool unknowing intended buyers, but it could equally also be just the result of 'shed job' with some innocent fooling around.

I do that with modern circulating coins (rarely) just to entertain myself. They all go back into circulation , because I can't see any point in keeping them.