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Author Topic: Is this Bronze Disease? Help appreciated.  (Read 3440 times)

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Eamon F

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Is this Bronze Disease? Help appreciated.
« on: July 17, 2018, 03:19:26 am »
Does this coin have Bronze Disease? I assume it does based on what I've seen online however the green doesn't brush off very easily. Very much a novice on the subject and any help would be greatly appreciated.

Offline Molinari

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Re: Is this Bronze Disease? Help appreciated.
« Reply #1 on: July 17, 2018, 07:39:38 am »
It looks like there is some on the back.  When you say it doesn’t brush off easily what precisely do you mean?

Eamon F

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Re: Is this Bronze Disease? Help appreciated.
« Reply #2 on: July 17, 2018, 08:15:13 am »
Read somewhere online that Bronze Disease could be quite "powdery" and easy to brush off. Though if thats not the case and one side does have some, what treatment would you recommend?

Offline stevex6

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Re: Is this Bronze Disease? Help appreciated.
« Reply #3 on: July 17, 2018, 09:18:59 am »
Yes, bronze disease is "powdery" and can usually be picked-off/disturbed with a toothpick ... however, if the green material is hard, then I usually thank my lucky stars and merely keep an eye on it (I wish you luck, either way)

Offline SC

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Re: Is this Bronze Disease? Help appreciated.
« Reply #4 on: July 18, 2018, 08:26:25 pm »
Yes, BD will be powdery.  A stiff toothbrush (cut down bristles) or a toothpick will brush some away without harming the coin.  Under magnification it will look like a fine powder.

The same colouring (especially in photos) can be found in very hard encrustations that are actually malachite (copper carbonate hydroxide) build up from the copper content. They are very hard and completely stable and safe.  They will look like crystal formations under magnification (even magnifying glass) and won't brush off with toothbrush or toothpick.

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Offline Cunobelin

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Re: Is this Bronze Disease? Help appreciated.
« Reply #5 on: December 15, 2019, 06:56:21 pm »
Yes, BD will be powdery.  A stiff toothbrush (cut down bristles) or a toothpick will brush some away without harming the coin.  Under magnification it will look like a fine powder.

The same colouring (especially in photos) can be found in very hard encrustations that are actually malachite (copper carbonate hydroxide) build up from the copper content. They are very hard and completely stable and safe.  They will look like crystal formations under magnification (even magnifying glass) and won't brush off with toothbrush of toothpick.

SC

I realize that I am late to the party on this, but that is such great information to have! It explains so much about pieces that I have that have harder green encrustations! Thanks a bunch for the explanation. :)

-Cunobelin

Offline Charles M

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Re: Is this Bronze Disease? Help appreciated.
« Reply #6 on: January 18, 2020, 11:51:53 am »
Looks like verdigris to me.  I would leave it be.

Charles M.

 

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