Really hoping for some input. Have been wanting to add a Marc Antony to my collection - as I typically look for budget coins - this one is priced as good as I’m gonna do, around $150 - well price wise at least… Is it Verdigris? or BD? or?? is it contagious to other coins? Can it be removed? Should I pass up this coin? Thanks you.
If it is BD, then the coin would have to be a fouree. I cannot tell from the image if it's a core of bronze showing through or if it's a mineral deposit. Either way, it's not a bad buy. If it turns out to be BD it can be treated, If mineral deposit maybe it can be cleaned. I believe this is an example of Legio XV which is not rare. In the Delos hoard there were 39 examples of Legio XV, second only in quantity to Legio II at 40 examples. My Legio XV examples :
Could be verdigris with horn silver. Toss in a solution of sodium thiosulfate, it typically doesn’t mess with the patina and removes the black pretty easily
These coins were typically heavily debased and are more subject to corrosion. That's a good price for a decent example of a legionary denarius and some visible corrosion is a reminder of their debasement (and the question of why they were).
If I recall correctly, the main denarius coinage at this time was ~96% silver. Antony's legionary denarii are closer to 90% (I've seen varying estimates), in line with cistophori and other eastern silver coins of the period. As suggested above, the encrustation is likely a mix of horn silver and verdigris. I think the coin is just fine as it is.
