FORVM`s Classical Numismatics Discussion Board
Numismatic and History Discussion Forums => Coin Photography, Conservation and Storage => Topic started by: Ron C2 on December 06, 2020, 12:53:36 pm
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Hi all,
I guess because I collect severan period debased denarii I don't often encounter horn silver and have little experience deciding if an encrustation is horn silver or just old dirt & minerals. From what I have read, copper-alloyed silver is generally much less susceptible to horn silver corrosion.
This coin has a few pin-point size encrustations that are lead-colored, which I know is the color of horn silver, but I don't usually see photos of it that look this small and isolated to little bits. I've only had the coin a short while, so it's not like I would see the progression yet.
Just in case, and on the general idea that I will encounter horn silver eventually - after reading up on it I ordered some sodium thiosulphate powder online just in case - won't have it for a week or two though.
Most of it is around the L in IVLIA, but there are very tiny specs of it on both sides of the flan in isolated areas.
(https://www.forumancientcoins.com/gallery/albums/userpics/51928/normal_Julia_Paula.jpg)
Should I do a precautionary sodium thiosulphate bath with a DW soak just in case?
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Quote: ". . . so it's not like I would see the progression yet."
Horn silver is not the same as bronze disease. Bronze disease can eventually destroy a coin, but i think horn silver is fairly stable.
From your picture, it appears the coin is lightly toned. I would not do anything to it that would get rid of that toning.
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I don' think sodium thiosulphate removes toning? But even if it did, silver retones naturally after a few years.