Greetings! I am interested in buying this Byzantine Tetarteron of Manuel I, but I am afraid that these small bluish deposits could be Bronze Disease (photo from the seller). Since I am a layman in this matter, I would like your opinion on this. Thank you all
Bright blue is usually bad new but some verdigris can be bright blue. Bronze disease is such an awful problem my suggestion would be to move on unless you are 100% certain - hard to tell from your photograph. I have read extensively on how to treat bronze disease and have yet to find anything that works consistently - I have tried everything - distilled water, high heat, sodium sequcarbinate (or something like that, fish tank cleaner -and more - nothing works really well to get rid of it Blake
I don't see any signs of bronze disease. BD is light green and powdery. Here is a pic of a coin with BD--
Thank you very much, I'll leave that aside! I have a numismatic trauma, I had two coins affected by this. I tried to do the procedure with distilled water and then let them dry well in the oven, but the process seems to have gone wrong, so the piece got even more damaged. I followed the instructions I found on a numismatic website, but it didn't work. So, if I find any suspicious stain, I immediately try to find out what it is. And since I'm a layman, I take the opportunity to ask my questions on the forum!
