Roman Silver

Maybe it's just the picture, but it looks like a really thick coin. Are you sure it's a silver coin and not bronze? All the same it's interesting to see how the two metals combined.

hu...interesting indeed.

it looks like a bronze coin to me instead of a silver.

Silver crystallization doesn't happen from "silver atoms realigning". It is a mechanical rather than chemical event (although at a microscopic level). What happens is that when silver and copper are melted together they don't fully dissolve. Since copper doesn't mix very well into silver the two start separating into bubbles with copper trapped in between sort of like bricks and mortar. Over time those "bubbles" start sliding past each other from stress and near the surface copper is eaten away from oxidation. It's as if the mortar turns to dust and the bricks become looser. Over time the whole matrix becomes weaker as the millions of little silver bubbles detach from each other.

In this case that there is not a silver coin. It's what is typically referred to as a "limes denarius" which is really little more than a fancy way of saying old counterfeit.

Ras

Are they 2 halfs of the same coin, or at least the same break? The deposits don't line up?

Good morning all.
The first answer is that this coin was in 3 pieces. I showed pictures of 2 of them so they may have looked strange. I will now show the bits put together so to speak.
As I say this is Antoninus but someone may be able to tell me more about it.






The pics above are with the bits together.Note the 2 single copper cores that run through the coin.These come through if I try to clean it back to silver. The remaining black sections are very much harder and a lot more difficult to clean. If the coin can be identified for sure it may become clearer if this coin is real or fake. I think it's a real Denarius.
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The piece above is on its own and is of Severus but was left in the same Lemon Juice for the same time but no other colours in the core.
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This piece above is also the only piece and is a Denarius of Gordian also left in the lemon juice-No change to the core.
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Compare to these 'silver' coins.





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The upper 2 pics is a 'Denarius' of Gordian - Copper coming through the plating.
The middle and lower coins I have not researched as yet so someone may be able to help me those (look at the Emperors nose in the bottom coin) Phew!!
I must admit that I am becoming very reluctant buying any more Roman Silver if this is what I get, and these are not the only ones that I have unknowingly bought.Other buyers may not try to clean their coins as I do.
I hope you all find this as interesting as I have.
Cheers.

The black one from the original picture is definitely a "limes"; ie., not silver at all. The middle one is a very debased antoninianus (apparently a Tetricus I) and the bottom one a fourree which is yet another type of counterfeit consisting of a silver bath over scrap metal.

The problem isn't that the Roman coins have little silver. It looks like you went for bottom of the barrel examples. I'm guessing all three came in a $5 lot or thereabouts? Here's a couple of links for coins of good silver that should cost no more than about $30:

http://www.ebay.com/itm/231425879881
http://www.ebay.com/itm/400827629387
http://www.ebay.com/itm/331418827479

Ras