ID and Cleaning Help for Trajan Billon

[Mayadigger]

Ave!

Yes, I'm not ashamed to admit that I'm stumped with this one.

ID would be nice, but perhaps Salem/anyone would chime in as to how to remove the red encrustations?

Trajan?

Billon 24mm, 13.2 gm. Alexandria Mint?

This is a nice coin and I'd rather not goof up the restoration.

Thanks all!

Kevin

[casata137ec]

Lemon juice soaks and manual cleaning. I got like 8 tets last summer that had that red crust from one degree to another and I tried a bunch of different ways, but lemon juice and manual was the best. My theory is taht the red is the copper/base metals leaching from the coin leaving the frosty silver and then oxidizing. The main issue is how debased the silver was. The more debased the gentler you have to be as the high points have a tendecy to collapse if too agressive.

The pics below are a before and after of one of my more successful cleaning jobs using this technique. There is still a bit of the red left, but it was originally coated from top to bottom.

Chris

[Mayadigger]

Ave!

Cool, I'll try it.

Thanks Chris!

Kevin

[wolfgang336]

It's been a long time, Kevin!

I don't believe your coin is actually silver, so lemon soaks will not be helpful.
Bust looks like it could be Trajan, certainly Egyptian [tetra?]drachm.

I'm not certain that this will respond well to cleaning at all... the surface looks too powdery?

Evan

[Joe Sermarini]

Nothing you can do to this coin will make it more attractive.  Right now it looks like a worn but as found ancient coin with little monetary value.  Anything you try will make it ugly and lower the monetary value.

[Mayadigger]

Ave!

Nothing you can do to this coin will make it more attractive... 

Joe, I quite agree with you. I had a 'gut-feeling' to leave it alone...and did so.

As I couldn't pin down the attribution anywhere from on-line sources, I sent the same pix to our friend David MacDonald. Below is his reply: please note his story about the 'floating tetradrachm'. FYI - My coin doesn't float! 

Hadrian, Year 5.  Rev.: Eagle.  Milne 980.  I do not think this will clean well.  Ammonia will remove the red copper oxide, slowly, but generally when an Alexandrian tet of the second century has this much red on it, it is also somewhat crystallized with a lot of similar corrosion along the crystal boundaries.  Cleaning off the red often leaves the silver core so soft you can scratch it with a piece of paper. 

Years ago a friend had a Nero tet that had had the entire free copper in the coin corroded away, leaving a silver sponge.  The coin weighed about a quarter of normal and would actually float for about twenty minutes until the water filled every little crevice.  Then it would leak water for about three days until it dried out.  Oddity!

This should be a lesson to us all, including me: Sometimes you just need to step away from the coin and leave well enough alone.

If the coin floats...it's done! 

Best,

Kevin