Silver Coin with Bronze Disease?????

[Jeremy W]

I have a Caracalla denarius and an Ant. of Gordian III that appear to have bronze disease.  Can I treat the disease the same way as I do on a a typical bronze coin?    I usually clean it off and then use Gringott's

I'll post a picture once I get home if that will help.

Thanks,

Jeremy

[Mark Farrell]

Interested in the photos, but silver cannot get bronze disease -- it is more than naming conventions or syntax, but actual chemistry. But let's see the photos. Perhaps you have a low-silver ant and a fouree denarius, in which case they could get bronze disease because they will have mostly bronze cores.

Mark

[awl]

It is not bronze diease chances are that either it a fouree as mharell said or it is gunk that has bonded to the coin. Once I saw a Antony legionary that has a green substance similar to the one that you are describing. It is either "horn silver" or the coin has crystallized.

[Jeremy W]

Here are the coins in question:

[awl]

It looks as if the coins are not fourees, but just in case, how much do they weigh? It appears that the coins have a substance that has bonded to the coins. Try to put them in lemon juice or heat them. Do not pick at them because they are nice coins aside from the mysterious green substance.

[Jeremy W]

The Caracalla is 2.93g and the Gordian is 4.72g.  I'll give the lemon juice a try(have to buy lemons) and report back.

Thanks,

Jeremy

[awl]

The weight seems right for the era. And by the way, if you clean the silver coins with lemon juice it is better you should purchase the lemon juice that is already in the plastic container. They usually come in 4 oz sizes and make it much easier than squeezing the lemons. It also last much longer too since it is sealable.  Just a suggestion 

[Jeremy W]

I'll pick up the little lemon juice bottle on the way home from the office tomorrow and give it a try.  Thanks for the help.

Jeremy

[bruce61813]

Looking at the pictures, they slook like fourees, at least the Gordian, or is there still deposit areas on the coins? I am looking at the area near the nose, it look like the plating has come off. It could just be tha color of the light. But the coins do show copper oxide pits, and that would not happen if the coins are silver as they should be, you would only get a mild green surface oxide from the copper mixed in the silver, not deep pits.  Can you correct the color and repost the scans? Otherwise , I would treat them for BD, it won't hurt silver, cut if these are fourees, it will save them. The silver version of BD is called ' Horn Silver ' and can be treated with sodium thiosulfate, it is usually a dull gray and is Silverchloride.

Bruce

[Jeremy W]

The coins and pictures are at home but in hand those things that you see are just deposits.  I'll see what I can do with the pictures when I get home. 

So I'll start by treating like BD and once I confirm that they are indeed silver, will move on to lemon juice.

Thanks for all the help.

Jeremy