Anceint Coin Microscopy

I see nothing consistent with the coin being fourree but the only way to be sure is to cut the coin in half and I wouldn't suggest that. What we see as corrosion products can also be explained by the coin being under 50% silver as are most Caracalla denarii and/or by being hoarded with copper coins. Fourrees tend to wear in certain ways and peel in regions not seen on this one.

Our modern coin's are not heated when struck, the pressure put to the die's makes the metal flow like a liquid. Filling in all areas of the die.
If highly polished and struck many times will give the cameo look as a proof coin.
These coin's were heated red hot, as they cooling off were struck leaving flow marks and a slip look to the letters as they pulled it a part.
As they were making these coin as fast as they could, the temp was always different. Leaving each coin with a little different surface.
also maybe in this case, the metal might have had slag or other metal's not melted ,flowing to the top of the coin and now are rusting in those place's, they sure weren't .999 fine, just a thought...

Dougsmit: Is it possible for you to post a picture of a fouree with corrosion. I guess most of us could learn a little, certainly me.

I do not have a photo of bronze disease having always rushed to treat when I saw it and not bought coins with it if I saw it first. The image below is from my fourree pages and shows stable green (hard) corrosion in a broken edge of a Julia Domna denarius. My pages have several other fourree photos that could be educational to anyone who cares to look.


whole coin:


I just checked the (solid but low grade silver) denarius that had BD (I keep that one at home for regular inspection!) and am happy to report that it shows no sign of relapse so I can't take a photo. I do believe that half of the times people on the list diagnose BD they are actually seeing stable corrosion but it is better to be safe than sorry and I usually stay away from suspicious coins on the theory that they are more trouble than they are worth.