How did this happen ?

[echidna]

What has happened here ?
Looks a bit like an extra sideways planchet.

[Robster]

No idea- but mighty impressive.! Will follow with interest.!

[Goldseeker]

Ram shot by a mysterious archer at night.................interesting error coin that.

[Fr45h3R]

Having a guess here but it looks like the dies were damaged by a coin that was not 'flat' when it the dies were struck, and this coin followed it.

[Australian coin]

Yes looks like there would have been something that damaged the dies, or some sort of die failure â€" die crack, or maybe rusty dies to the extreme.

[purplepennyhunter]

Similar

[emu666]

What has happened here ?
Looks a bit like an extra sideways planchet.

I believe that your coin is heat damaged. What you are seeing are bubbles. They originated as tiny flaws in the planchet that contained small pockets of air. With extreme heat, that air expanded to produce the reasonably large bubbles you are observing.

[jrg_from_oz]

Looks to me like the die could have been deliberately defaced by scoring a line across it, in a similar manner to the way dies for limited editions are defaced to prevent further strikes.

But as to why a circulation die would be so treated - I have no idea.

[emu666]

If a coin such as this was created through damage or defacing the dies there would be more than one example and it would almost certainly be mentioned in the catalogues. The reason it isn't in the catalogues is that the damage is to the coin itself as I stated earlier.

If I may draw your attention to the the spot I have marked on the reverse below. You can see how the metal on the raised area has been pushed in subsequent to the raised are forming. The metal bubble will be comparatively thin and it will be reasonably easy to push in mo0re of that area.



On the obverse there is a spot where the bubble has started to break open. A bit of work with a thumbnail should break it open sufficiently to show the hollow area under the "bubble".