Bullion discoloration - your experiences?

[Bluehawk]

... So many kinds and sources of bullion on patches, insignia etc etc etc.

 

Has there been or is there any personal knowledge out there of:

 

1. What actually causes discoloration when it occurs

2. If humanly possible to know, how many kinds of different bullion "thread" are there

3. For how long has bullion been used in making insignia etc.

4. Is there any treatment to recommend after discoloration

5. Is there any method of preventing discoloration

 

This topic has probably been covered on USMF? If so, please delete.

 

[Cololab]

I'll answer some of your queries. Bullion insignia has been used by the US military at least as far back as

Revolutionary War times. The discoloration is caused primarily by oxidation although exposure to chemicals can have a negative effect on the gold/silver wire thread. I think it would be impossible to determine how many different gold/silver wires have been made and used over the centuries.

 

You might try gently rubbing the item with a jeweler cloth, but you are going to end up with a likely unsatisfactory result. I would advise against doing anything as the aging of the bullion is part of the history of the item.

[Bluehawk]

^ Thank you.

 

I suppose modern/contemporary bullion can also be/is manufactured using plastic/polymer threads, as well as traditional metallic ones.