Need Help Identifying Roman Provincial Coins!

Just got back, great job everyone! Ben excellent detective work.

I do have a method, one that does work and I have done myself. But now I sit and think about it I see some issues with it, so I'm going to do some reading and thinking about the 'conventional wisdom' and see if I can't puzzle out something a little better. Here is that method, nonetheless:

Get out a wooden toothpick (or a sewing needle if you feel confident) and carefully remove any powdery green stuff. Don't use water to remove the loosened powder - perhaps use a toothbrush. You will likely see metal beneath - that is a sad fact of the process, but left untreated, the coin has no chance of surviving the next 2000 years. That removes a lot of the issue, but you will still need to leech the offending ions out of the surface of the coin. There are competing schools of thought on how to do that, but the simplest (and most time consuming) is to dissolve them into distilled/de-ionised water.

Basically, rinse the coins with distilled water, then dry them off, just to ensure the last of the loose powder is gone. Get a small, airtight container and fill it with distilled water and put the coins in it. Every couple of weeks (perhaps a little more regularly at first), check to see if there are any tiny spots of green - if there are, remove them as before. Every time you check the pot, change the water; it is good practice rinse and dry each coin each time as well. Eventually the number of ions still adhered to the coin will reach an inconsequential number and you will stop seeing green spots appear on the coins. Treatment can then be stopped, but you then need to make sure the coins are properly dried, which can be achieved with some time in the oven (low temp, 20-40 mins or until golden brown - okay, maybe not that). When I treat coins for BD, I wax them with Renwax afterwards but that is frowned upon in some circles as the wax is not easy to remove - I do it because it helps keep the coin dry and stops environmental damage and (in my own humble opinion) I think it looks good. Keep an eye out for any new spots in the future - the quicker it is caught, the less damage there will be.


A bit more reliable is a chemical intervention using a chelating agent, which is what the museums do. I have never tried it myself, but you might want to give it a go. Popular treatments use sodium sesquicarbonate (this is the 'hobbyist' way), sodium carbonate (for the more highly patient hobbyist) or benzotriazole (carcinogenic, so a bit more specialist).

Once I've had a read and a think, I might try writing a short summary guide to treatment.

Spence I've used that method with some success. See below.



Two Things:

1. It will most likely change the color or patina of the coin (as you can see_.

2. Definitely do this
I did not, and now I see the BD has returned.

To identify Roman provincial coins :
http://rpc.ashmus.ox.ac.uk/ or
http://rpc.ashmus.ox.ac.uk/coins/
for Alexandria : the Dattari catalogue . albert