Hi everyone, I want to share something with you all. It is probably mostly my fault, I guess since I did not open this lot of coins as soon as I received them. That would have been about 4 months ago. I have often waited to open coins I ordered so that I don't get the lots confused. Anyway... I had two lots from this particular seller from whom I have purchased without any difficulties in the past. One packet of coins I finally opened the other day was normal but when I opened the second packet, this is what I found. I snapped a few quick photographs and then wrapped them up and set them aside. I read a few posts here on Bronze rot. I never saw it before. I guess I will rinse them off in distilled water a couple of times and then soak them in distilled water for a day or so and then softly scrub with baby tooth brush, rinse them again in distilled water then dry them well and sit them aside apart from any other coin. That is the last time I will keep coins wrapped up for months before opening the packages in which they arrive. A word to the wise (as my Dad always said) is sufficient. Thanks in advance for any advice. LaC
Interesting. It reminds me, of when I ordered some tulip bulbs for my Mom, from an internet company, for Christmas. I waited a few days, before I opened the packages. When I opened the packages, the inside of each package was moist, and the bulbs had green rot on them. Not bronze disease, of course, but a similar color. I tried to cut off the rotten parts. But when my Mom planted them, very few of them grew. Since then, I haven't ordered tulip bulbs, from any internet company. But if I ever do it again, then I'll be sure to open the packages immediately. In fact, if I remember correctly, each package said "OPEN IMMEDIATELY", on the outside of the package. With your coins, I wonder, if moisture accumulated inside the packages, perhaps because of temperature changes. For example, if the seller lives in a hotter part of the world, and if you live in a colder part of the world, then the drop in temperature, could cause water to condense out of the air, within the package. What do the seller photos look like? Do these coins resemble the seller photos? What are these coins supposed to be? Late Roman bronze coins?
P.S. : Or, perhaps some of the coins already had a mild case of bronze disease, perhaps on small parts of some coins. But after 4 months in the package, perhaps the bronze disease progressed, and completely covered some of the coins, and perhaps even spread to other coins. I'm not an expert on bronze disease. As for how to fix the bronze disease, I'm not an expert on that. There are many CoinTalkers, who seem to know a lot, about that. I'll wait, and see if any of the experts, provide info.
P.P.S. : Or, perhaps, the coins looked like this, before they were mailed. That's why I'm wondering, if there were seller photos, and if these coins look like the seller photos. Were the seller photos in color, or black and white? The lighting conditions, for the seller photos, can also make a difference, in whether you can see green or not. Or, the coins could have turned green, between the time, when the seller photos were taken, and when the coins were mailed.
P.P.P.S. : If I remember correctly, I have seen photos of hoards of uncleaned ancient coins, in which the coins looked similar to your coins, right after the coins were pulled out of the ground. You may just need to clean off the outer layers of dirt. But I'm no expert.
Hi @Theodosius !! Great to get a chance to say howdy to you. What? Huh? Really? Might not be? I was just reading a thread the other day on CT where a couple of very knowledgeable numismatists who concentrate on ancients were saying that when light greenish powder falls off, that that is one sign of bronze rot! (Actually, in that thread there was a bit of back and forth about how to diagnose bronze rot; but, I was of the mind to follow the advice of the experts). :-D Oh! Egads! @sand ! Thanks for all your suggestions. Yes, the coins look like the ones in the sale photos -- EXCEPT, that is, for all the green stuff!! I trust the seller to not have sent something other than what I purchased. I am going to start cleaning them this evening and will post photos of what happens. Thanks for looking at these sad looking little things. I hope it isn't the rot. I am going to read more about it.
I'm no expert. It seems conceivable, that under that light green powder mixed with dirt, there may be a layer of nice, hard, inert, dark green patina, which would be very desirable. Perhaps the coins initially had unstable bronze disease, which mixed with the surrounding dirt, causing the surrounding dirt to turn light green. Then, perhaps, after 1000 years, the unstable green stuff on the coins, eventually turned into nice, hard, stable, dark green patina. Let us know, what you find, underneath.
Hi again, I had a chance give those questionable coins a soak in distilled water. Here is what they look like tonight. They are now in two separate baths. I did not want the very green ones to be soaking with the less green ones.
Hi, what I was trying to say is if it is light green and powdery and rubs off then it is bronze disease. If it is hard and stable and doesn't rub off easily then it could be a more benign patina. If you are suspicious of those green ones keep soaking them into distilled water and change the water out every day. Brush with a soft toothbrush every day and see if the patina changes. If the water turns green and you're losing material then there's more of a chance that it's bronze disease.
By doing this, you are actually treating your coins for bronze disease, and hopefully curing them of it. It might not be necessary, but you won't hurt your coins by doing this. Continue this treatment for 2-3 weeks, then dry the coins off--some people bake them in an oven at 200 degrees F for about 40 minutes or so; I don't--and let them sit out where you will see them often. If a coin has bronze disease, and you haven't completely cured it with this treatment, within a month of so you will see a light green powder build up on the surface of the coin. If this happens, then repeat this process for that particular coin; the rest are probably okay. But if you do have to repeat the treatment, treat each affected coin individually, in its own container.
Thanks for the feedback and advice @Theodosius - Yes, that is what I understood from your post and why I am pretty sure I am seeing Bronze Disease on these coins. And also, @gsimonel, thank you, too. I will do as you both suggest. The first three rinses with agitation of the coins released green colored water with some chips of whatever else was loose on the surface of the coins. Then after a few hours, some other loose debris fell off with just a tinge of green color. After that, I took the first set of photographs on the three towels. As I said, some coins were separated from the others for the second soak. The very green ones I sat on a saturated paper towel and then covered with the distilled water. I don't know exactly why I did that. Anyway, right now they look like this: Later this evening I may try to brush them a bit more and see what other crud comes off. Thanks again, LaC
The one at 3:00 in the 2nd photo concerns me most. The others look pretty beat up, but stable. Maybe just set those aside and keep a close eye on them to see if any green powder starts spontaneously building up on the surface.
Given the circumstances, I would look at these coins as an investment in learning to treat bronze disease. Better to sacrifice a group of relatively inexpensive coins now than to lose an expensive item down the road. I say 'treat' rather than 'cure' because practically speaking, the reaction can only be halted, not cured. Bronze disease behaves in the manner it does because it is not a single chemical reaction but a repeating series of reactions where one feeds on the byproduct of another in an endless cycle. The basic reactants are copper, oxygen and chlorine (from water). Put simply, a coin with bronze disease is eaten away by hydrochloric acid. The object will eventually be completely consumed if not treated. Treatment involves breaking the cycle and then depriving the reaction of one of the essential ingredients - water. Even the small amount of water in the air on a humid day is enough to start the reaction again. This wikipedia article covers the basics, including treatment. One method commonly used by collectors involves sodium sesquicarbonate which will neutralize any remaining acid and convert reactive cuprous chloride to relatively inert cuprous oxide. Maintenance involves regular inspection and keeping the object as dry as possible. Good luck!
Hi @dltsrq -- You are perfectly correct about seeing this experience as a chance to learn about 'treating' bronze disease. I was thinking that very thing before I took my afternoon nap! I enjoy learning anything connected with cleaning and preserving ancient coins. I am appreciative of your input. Thank you. I will read that article and look into the sesquicarbonate.
I think I see some Judaean coins in the top two pictures that may clean up, with a bit of work. Good luck.
