Green/Red Deposit on Constantine I Argenteus

[Minos]

Hello! Would there be an easy and gentle way to remove the green/red spot on this argenteus. Tried softly with a toothpick without any success. Would rather keep it this way if there's no risk free way to do it but was wondering if somebody had some tricks to share. Thanks!

[awl]

Try a pin vise it is harder and more precise than a toothpick and they can last awhile.

[Mark Farrell]

Be VERY careful cleaning this coin mechanically -- it's my understanding that argenteus had a very high silver content (can someone confirm this?), so it may be better to clean it chemically. Very high silver content coins can get dinged pretty easily.

Try short soaks in lemon juice, say 1-2 min, increasing up to 5 mn. Stop if the coin begins to discolor or otherwise get funky. After each soak, brush gently with a nylon bristle brush.

Do NOT leave coin unattended in the lemon juice for more than a minute or two -- you want to watch it pretty carefully, even if the coin is indeed an argenteus.

Report back and let us know how it goes, if you don't mind.

Mark

[Heliodromus]

I don't know what it means for the recommended cleaning method, but this type is what's sometimes referred to as a pseudo-argenteus. It's made of an alloy of 75-80% copper (or bronze) and 20-25% silver.

Ben

[Mark Farrell]

Aha! That makes a BIG difference. Do NOT use lemon juice! Thanks for the head's up, Congius.

Try picking the green deposits off mechanically then -- the lemon juice may pit the surface more and/or make the surface more of a copper color. Use a very thin needle to very gently pick the deposits off the surface -- you will need some type of magnifying glass for this. Be careful, though, as the needle can really scratch the coin.

Othewise, you could try soaking the coin in Gringott's #1 for a few hours to see if it loosens the green stuff.

Post an update to keep us informed!
Mark

[Mayadigger]

Ave!

Looks more like a silvered Ae 3 to my eyes, but I'm no expert. If it was an argenteus, it would be silver, and we wouldn't see the copper encrustations leaching through the silvering on the Rx. Hmmmm?

The Obv is done. A DDDP #1 will easily remove the green on the Rx in about five minutes time. No lemon juice, please.

Kevin

[vic9128]

Looks more like a silvered Ae 3 to my eyes,

As Ben said, this is a billon coin. It is roughly 25% silver, and 75% bronze.

[Minos]

Thanks for the feedback. As others pointed out, this is a billon argenteus, so a quite low silver content wich explain the green/red encrustations.

@Kevin

Could you tell me what DDDP #1 is and where to get it?