What to do with some copper coins from 1500-1700?

[1jester]

I have some old coppers from Leige, and before I dump them into acetone (or MS70...just kidding ) do you have any suggestions? They were bought at an estate sale and are currently in mylar 2x2s, but I've found others from the sale (silver coins) had been previously exposed to PVC. So far I've bathed everything in acetone to help conserve the coins. I'm a tad bit hesitant to do this with 400 year old copper, but I've had success and no trouble with other copper coins. That is, with the exception of some coins which I believe had been cleaned earlier in life, and retoned perhaps. Those coins, after acetone, displayed a tiny bit of purplish toning. However, on most copper coins I've noticed absolutely no change in coloration after acetone.

[JamminJ]

Gee, that's a tough decision.

 

Unfortunately, I've never used acetone so can't offer any information on how your copper might fare.

 

How many do you have? Maybe you could experiment on just one or two of the less prized specimens and see how they turn out.

Considered olive oil? Seems popular among the ancient collecting set.

 

I'd hate to see them acquire the ugly fooled with copper look.

Sorry I have little to offer, but good luck!

-JamminJ

[1jester]

I've done a lot of work with olive oil, and found it quite effective in many cases. Usually I use acetone to rid the coin of the oil when I'm done, so if I use olive oil, I pretty much have to use acetone anyway. That is, until I get some Blue Ribbon, which I've heard is good for long term preservation.

 

Anyway, I've decided to do nothing with the coins until I get some BR. I don't think there is any real accumulation of anything on the coins, nor any verdigris, so I don't want to bother them just yet. Also, I'm not sure if they've been exposed to PVC or not; some have a sort of greasy feeling to them, but perhaps it's due to earlier exposure to oil/BR? I just don't know right now and will leave them alone until I get more advice.

 

To answer your question, I have about 8 of them, and I did drop the youngest one (1750 4 Liards) into olive oil because it has some grimy feel to it. I'll let it soak for a while, few weeks or so, and then rinse it with acetone.