Author Topic: Bronze Disease  (Read 27312 times)

0 Members and 1 Guest are viewing this topic.

Offline Pellinore

  • Moderator
  • Honorary Member
  • *****
  • Posts: 1 137
    • Some numismatic books for sale on our website
Re: Bronze Disease
« Reply #45 on: October 13, 2017, 01:24:01 PM »
Well, here are pics of the coins that I have given up, an Elymais tetradrachm and a 12 nummi from Alexandria, purported to be minted in 617-629 during the Persian occupation. The pics made from the side show that both coins have split and inside a squall of BD is forming, too.
-- Paul


Offline bruce61813

  • Moderator
  • Meritorious Member
  • *****
  • Posts: 673
    • Gringgotts Coins
Re: Bronze Disease
« Reply #46 on: October 15, 2017, 03:28:33 AM »
I would not give up. Use the BD mix, in a heated solution, give it a scrub, at least every 72 hours.  change the solution after the scrub. The bright blue is safe, it is Azurite and related to Malachite. Both are stable, hard forms of copper oxide. The may be salts deeply embedded, I have seen this type of layering before. I had a coin split into 3 layers. None could come up with a definitive reason for it. Possibly the original plan had flaws.

Bruce