UNCLEANED COINS

[hotwheelsearl]

1 hour ago, Nerosmyfavorite68 said:

Yikes!  Sounds dangerous.

Per DimitriosL's coin, I remember coming across a LOT of Gordian III era ants with rust while going through HJB pick bins in the 1990s.  However, these had more pronounced rust.  There was no doubt with these.

Per an earlier question, should I stay away from uncleaned Parthian silver with mint green highlighting? Will it damage silver to leave it that way?

Depends on what exactly the green is. If its verdigris, it's generally stable and can be left alone. Verdigris is typically a darker green.

Mint green, if flaky/chalky, is bronze disease and should be avoided at all costs. That is unusual for silver coins though, unless a fourree on a core of bronze, or a really awful low silver content billon with more bronze than silver.

[madhatter]

Cleaning in progress.

The coin was soaked in demineralized water, for more than a month, but it does not affected green incrustations. So i tried different aproach - since the green stuff was very hard, started with pressing it with unsharp metal object, working on very small area at time. The incrustations started to crack, and i managed to remove big part of them, but reached a point where i cant go any further. Although I used an unsharp tool, it can slip very easy, and to cause scratches. At that moment the coin looked way better, than at start, but still far from the condition i wanted to achieve. 

Search for a way to proceed lead me to citric acid. Like I said before - I was sure the coin is not a fouree. But I couldnt find a guide anywhere on exactly how to do it - no proportion of DW and citric acid. Many sourced simply say - citric acid will help on silver coin. So i took a shot - squized a lemon, and put the coin in the juice for 5 min. The check on the 5th min show little progress. I left the coin in again, and went to gym 😎 After hour and I half, I went back home, straight to check the coin, hoping that I will not find it all porous. On the contrary - found most of the green mineralization dissapeared, and the brown under it too. It still has some hard dark stuff, on some areas, but for now, im more than happy with the result, and will leave it like it is. 

If i have to do it again, I will probably skip the mechanical atempt of cleaning, and would go straight to citric acid, if im sure im dealing with high silver content coin.

 

 

Edited April 30, 2023 by madhatter

[Nerosmyfavorite68]

Wow, it does look better!  You did well!

[DimitriosL]

3 hours ago, madhatter said:

Cleaning in progress.

The coin was soaked in demineralized water, for more than a month, but it does not affected green incrustations. So i tried different aproach - since the green stuff was very hard, started with pressing it with unsharp metal object, working on very small area at time. The incrustations started to crack, and i managed to remove big part of them, but reached a point where i cant go any further. Although I used an unsharp tool, it can slip very easy, and to cause scratches. At that moment the coin looked way better, than at start, but still far from the condition i wanted to achieve. 

Search for a way to proceed lead me to citric acid. Like I said before - I was sure the coin is not a fouree. But I couldnt find a guide anywhere on exactly how to do it - no proportion of DW and citric acid. Many sourced simply say - citric acid will help on silver coin. So i took a shot - squized a lemon, and put the coin in the juice for 5 min. The check on the 5th min show little progress. I left the coin in again, and went to gym 😎 After hour and I half, I went back home, straight to check the coin, hoping that I will not find it all porous. On the contrary - found most of the green mineralization dissapeared, and the brown under it too. It still has some hard dark stuff, on some areas, but for now, im more than happy with the result, and will leave it like it is. 

If i have to do it again, I will probably skip the mechanical atempt of cleaning, and would go straight to citric acid, if im sure im dealing with high silver content coin.

 

 

Impressive results!

[expat]

This Julian II was heavily encrusted when I got it. It has been soaking in olive oil for 7 days. A brief scrub with a soft toothbrush and it now looks like this. Unsure whether to do anything else. It only cost 2.40 euros

BEFORE

AFTER

 

Comments, tips or advice, all are welcome

Edited May 1, 2023 by expat

[DimitriosL]

9 hours ago, expat said:

This Julian II was heavily encrusted when I got it. It has been soaking in olive oil for 7 days. A brief scrub with a soft toothbrush and it now looks like this. Unsure whether to do anything else. It only cost 2.40 euros

BEFORE

AFTER

 

Comments, tips or advice, all are welcome

Good results without using any chemicals or time-consuming processes. I 'd say you were in luck. Seems pretty decent to me, can't think of a way it could be improved.

[Coinmaster]

On 4/14/2023 at 7:15 PM, DimitriosL said:

I also bought this coin for a friend in a previous auction for a low price. I love the portrait but I would prefer if the rust(?) was gone. Does anyone know if this is possible, to remove colouring like that?

You can try this with a soft eraser.