Author Topic: Is this Bronze Disease or related to Zinc or other and how does one proceed?  (Read 1143 times)

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Offline Geode101

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I am a beginner and have recently started trying to collect Kashmir Sultanate coins. The image shown is of a Kaserah of Muhammad Shah GG K 47 which weighs 5.38 g. On the obverse (viewer's right hand side) is a whitish region that doesn't quite look like most of the bronze disease shown in at least some of the messages in the 'Cleaning, Storage and Conservation' section. Is this a variety of bronze disease or due to an interaction with zinc or....?

Should the coin be treated?

If you were a beginner and the effect is dangerous to the coin, what should a beginner do?  I am elderly and would feel uncomfortable using acidic, alkaline substances, boiling. I would have no trouble with olive oil, and if something toxic was involved would prefer a ready to use commercially manufactured easy to use product.

Thanks so much for any advice.


« Last Edit: May 06, 2015, 05:18:19 AM by Geode101 »

Offline Figleaf

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It is not immediately clear to me what the white stuff is, but it doesn't look too bad. Something that was spilled on the coin, maybe. I think it is on the coin, not in the coin.

The first thing to do would be to wash it softly (no scrubbing) in soapy water, rinse and dry well. This should remove fatty substances but it should not affect the patina. The second thing to try would be acetone, which would remove paint, plastic debris and glue (the white stuff may be dried glue), again without affecting the patina. Olive oil would probably do nothing on the white stuff. It's good for softening dirt and lightening oxides, but your coin needs neither.

Many of us are of pensionable age. It's not important. What is important is capacity and willingness to learn. You'll do fine.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Offline Geode101

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Many thanks for your expert, speedy reply. I'll give your advice a try. :D

Offline Geode101

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In the 'Cleaning' section, there are several notes regarding the use of ultrasound. Is this a piece of equipment that can safely be used, in your experience, on copper and silver based Kashmir Sultanate coins and, if it is, if one follows instructions, when is it best used?  Amazon offers a model costing about $26.

Offline Figleaf

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Go for it, Geode. It will not help you on this particular coin, though. Ultrasound is excellent for hard to reach loose dirt. It will not harm patina. It is best on dirty, high graded, machine struck coins. An unc coin will remain unc. but a dirty ef may just get a better grade. Don't expect miracles. It will not remove oxides, chemicals and dirt compacted into a hard mass. It may shake hard dirt enough to become vulnerable to a wooden toothpick attack, which beats the olive oil treatment timewise.

As a bonus, ultrasound is perfect for cleaning spectacles and jewellery.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Offline Geode101

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Thanks so much, Peter. It is so nice to have experts willing to share their knowledge to get beginners going in the right direction!  :D