Thanks Guys. Is this the right forum to ask for advice? I've soaked in DW and brushed with toothbrush - the 2 top left coins are silver in appearance (but not silver coins if you know what I mean) they have green, almost crystalline deposits. Not like other green patina I have seen. Joe says "if it starts green, it should stay green" but is this likely to be BD? If so, how should I progress it?
Your first coin may have BD, the lighter green patch looks like it might be, probe with a toothpick, if it is powdery then you will need to treat it, ( at some point! ) .
I believe that BD treatment trumps
patina preservation, after all, there is a chance that all you might be left with is a pile of green powder, so either buy yourself some form of BD cure, or you can try cleaning the coin first, then drying it out
thoroughly and keeping an eye to see if the BD is active or not... sometimes it stays dormant, and is not a problem.
As for the harder, darker green stuff, this is natural
patina caused by the reaction of the copper in the coin and wherever it spent the last 1000 years or so...
You might find this very hard indeed, so try and only remove any that needs to be removed, ( using a
dental pick or sharpened steel welding rod ) but anything sitting on top you can attack quite vigorously without fear..
Good luck once more!!!
