What is This Error?

[SteveB00 0]

I'm in Australia and have inherited a bag of coins, including some from the UK. Most were unremarkable and I've passed them on to coin collectors here. However, the bag contained two error coins: one I've identified as an Australian $2 "die adjustment error" (very weak strike) and then there's this. Does anyone have any idea what has led to this coin? I've considered that it might be post-mint damage, except that an impression of the extraneous "lump" appears on the obverse of the coin, suggesting it was present when the coin was struck. It's certainly firmly part of the coin with no hint of a gap between the "lump" and the rest of the coin.

I'm stumped. Has anyone seen anything similar? Does someone who knows more about how these coins were minted perhaps have any insights?

Thanks in advance, Steve  = : ^ )

[Rob 2,996]

Looks like someone made a hole and then plugged it.

[SteveB00 0]

Thanks for the reply. There's no evidence of any damage on the obverse of the coin, except that it bulges a little under the 'lump' on the reverse, which has led to more wear where it bulges. I'll upload a higher resolution image and hopefully you'll see what I mean.

The only idea I have that I think could lead to what I see is that a blob of moten metal has fallen onto the blank planchet, which might explain the thin bit at the left of the 'lump'. Then the extraneous blob has set before the planchet was struck.

Thanks again.

 

 

Edited September 25, 2019 by SteveB00
Replace image

[Paddy 1,539]

There is no evidence of the reverse pattern in the blob, so it was not there when the coin was struck. So I would say this is post mint damage - someone has added the blob, either to make it into something (a large button?) or messing around in the workshop. Subsequently it has gone back into circulation and got the wear to the face.

 

[SteveB00 0]

Thanks for the reply. You could perhaps say that, because the blob is raised above the rest of the coin, the pattern has worn off it. However, because it is raised, you'd think that it would have prevented the rest of the obverse—certainly the part immediately around the blob—from being struck and there's no evidence of that, so it is most likely something that's happened post mint.

If you attached (How? Welding??) something to the coin in order to make something, why would you then hammer it hard enough for the thing you attached to show through the coin? And if you were making, as you suggest, a button, wouldn't you want the reverse, rather than the obverse, to be the visible side?

I'm still flummoxed.

Thanks again.

[blakeyboy 1,601]

11 hours ago, Rob said:

Looks like someone made a hole and then plugged it.

I'm with Rob on this- looks like a practice braze.

The fill metal looks to me to be a different alloy, as a braze filler rod would be.

The brazer didn't use enough flux either, or didn't clean the penny properly, or didn't apply sufficient heat.....

[SteveB00 0]

Thanks for the reply. There's certainly no hole in the coin, but what you say about a practice braze makes sense. Can you think of some reason to then hammer the coin hard enough that an impression of the lump you made on the reverse can be seen on the obverse?

Thanks again,

Steve  = : ^ )

[blakeyboy 1,601]

Well, If I wanted to practice filling a dent in copper or bronze with a braze, I'd put a dent in a penny, and have a go.

[SteveB00 0]

In that case, it's not much of a dent (and there's no hint of any deformation around the the lump) and the deformation on the obverse is exactly the shape of the lump, implying it was made by the lump, which is an irregular shape. Plus, no effort has been put into making it look "finished", which I think would if you were practicing your brazing skills.

I'm still flummoxed.

Thanks yet again.