Hi guys, I just bought a few cheap ancients from a guy who had just got them out of the ground and was wondering how to get the dirt off them safely. I've researched on half a dozen sites and forums and they're all saying different things. Some say use olive oil, mineral oil, distilled water, lemon juice, or a mixture of two. So since I have mineral oil and lemon juice at my disposal, I decided to mix a very small amount of lemon juice (~1/2 tsp) with maybe a half cup of mineral oil and stirred them together. This didn't create a homogeneous mixture and the lemon juice settled to the bottom, and had surrounded the coins after I left. After about 2 hours I came back and the lemon juice is around the coins and has turned green(!). I assume this isn't the dirt coming off, but the patina. I don't have any previous experience or knowledge with cleaning coins, so I wanted your guys' opinion. Any ideas? (Also, I know cleaning is generally bad for coins but these are caked in loose dirt and haven't been treated by the previous owner, so I feel like cleaning them properly would have a positive outcome.)
Lemon juice, being acidic, is going to react with the coins and destabilize the surface. I'd be really careful doing this. I'd want a good look at the surface crud before deciding whether or not to remove it, and that includes the verdigris. Chunks of dirt I'd remove with a green rose thorn under magnification. Ask on the Ancient Forum what they recommend.
Yep...what @messydesk said about examining the coin well before deciding whether to clean it at all and the method to use if cleaning is warranted. But now that you have this situation, why don't you take some photos of them and post them on the ancients forum? I work at cleaning extremely crusty, grimy, worn ancients and I will be glad to see what is going on with your coins and give you my two cents (ugh!) about what you might do next, if anything, to make them better. P.S. If the coins truly had only "caked dirt" on them, then your job would have been quite simple and I would have recommended no wetting of the coin at all. Too bad you did not post pictures of them before you began. But let's take a look at them now.
I tried lemon juice more than once back when I did this 15 years ago with ancient uncleaned coins and I had nothing but poor results from doing so. I recall that the lemon juice turned some areas of the bronze coins white. Additionally, it made them look porous in the areas in which there was a reaction.
Sometimes just soaking them in water and dish soap, then rubbing them between your fingers is all you want to do.
Okay, thanks for the help! I have more coming in the mail, which is why I wanted to test my method now so I don't mess up the other ones too. Here's some pictures: My biggest worry is the raised crusty parts. I don't know if it's dirt or a peeling part of the patina. They have terrible quality, sorry. ;-;
Good morning @CopperGenie. Before even deciding to clean a coin, I want to spend some time with it. Really looking closely at it. And sometimes photographing it as you have done here allows a good look at it. Sometimes, though, holding the coin away and not seeing it closely gives a better chance to get an idea about possible attribution. Have you tried to figure out the attribution of this coin yet? if you haven't, you might check here: https://www.tesorillo.com/aes/110/110i.htm I love this coin already. I've never seen it before. It looks like a double victory but I've never seen a double victory with a VOT before. (but i'm a newby so there's still TONS of reverses I have not seen). The legend on the obverse says IMP CONSTANTINUS PP AVG. And I think it is Constantinus I Magnus (but I am not absolutely positive as I just took a peek). I think your coin is not in horrible condition. It is just crusty and dirty. I say go very slowly. If you are in a rush to clean it, you are the not the person to do the job. (sorry!) (No. Not sorry!) This is a wonderful coin that has great potential I think. If you had to begin to clean it, then it would be a child's first toothbrush dry on the dry coin with the lightest stroke - and stroke in one direction from the interior of the coin outward and let the stroke carry off the edge of the coin. I like to hold the coin perpendicular to the floor so that whatever loosens from the surface of the coin has a chance to fall away and not rest on it. I like to put a piece of white paper underneath to see what I 'catch.' After the first brushing I would study it again before deciding my next step. There really can not be (in my humble opinion) any automatic, rote one-size-fits-all procedure in ancient coin cleaning because each coin is an individual case different from the next in some respect. Each should be treated according to what it requires. After a light brushing then perhaps - PERHAPS - with this coin I would put on my magnifying eye glasses and take my professional scalpel with a brand new blade and in the tiniest area where the soil is most thickly caked on see if I can begin to loosen the top crusty soil from the coin without touching the surface of the coin. This is delicate work - like surgery. Sometimes my hand is so tense it will tremble and I have to stop and relax. I have an array of tools, mostly home made, like the bamboo skewer that has one end frayed by cutting it with the scalpel a bunch of times and another I ran across a food grater to roughen it up. Those are handy tools for getting in small places. I have made those same types of tools with slimmer wooden objects. Whatever I can find that looks like it will work. I have a couple of chop sticks as well. And this is why getting the attribution of your coin done as early as possible is so useful. You will have a photograph of your attributed coin' at your side as you clean your coin and you'll know what to expect to find and where on your coin as you work on it. @Nas is not incorrect about soap and water, but I say very rarely and maybe after all the crust is removed - maybe. If you go under your soil crust and find a layer of tar substance, i think you will regret having wet it at this point. By the way, there are ways to restore a patina. I want to become proficient in that at some point. I hope this helped.
Acetone, or acetone then Xylene, followed by an acetone rinse. But yours is an extreme example... some members may not like this next one but using a toothpick may be good if there are pieces of dirt stuck. But obviously, you'll have to be very careful - maybe even use the toothpick while the coin is under acetone / Xylene. Otherwise, I'd just leave it.
Ancients bronzes are not the same as modern or even 300 year old copper. Curation has to be approached differently. @LaCointessa seems to know her stuff (or has convinced me that she does) and I would be inclined to follow her advice, which is more in line with archaeological conservation than simply removing surface contaminants from a metal surface. Even just the concept of a metal surface typically doesn't apply very well to these. Perhaps ancient and modern gold are handled similarly, but 2000 year old bronze is a different beast.
Hi @messydesk. If you are referring to @iPen's suggestions of Acetone and/or Xylene, I can say that I have acetone on hand and I use it when I am working on a sticky tar-ridden coin. I find that it helps dry out a coin. What I mean is that there will be times when I have held a coin in my hand for such a long time that it becomes warm and the warmth makes the tar substance on uncleaned or less cleaned portions of the coin get into cleaner parts of the coin. That means I'll be re-cleaning areas and I want to avoid that for at least two reasons (it's a waste of time and it may cause further wear on an already worn surface). I find a dip in acetone and then letting it dry tends to "cool off" a coin and it dries out and working on a "tar-ridden" coin is easier (sometimes, with some tools) when the surface of the coin is not warm and the tar is not softened by body heat. Disclaimer: I am a newbie. I am not an expert or professional coin person by any stretch of the imagination. I am, however, extremely interested in learning how to clean these extraordinarily crusty and grimy/tar-ridden ancient coins. I am also working on coins that appear to have no features visible on them whatsoever; and, I am trying methods to bring the features and legends of those coins back, so to speak. I am making some progress there. All of this is fun but I can not guarantee or even suggest that I have the answer to any specific coin cleaning problems. Plus, while looking at photos of coins here on this thread is helpful to understand what the OP is working on, it can not compare with actually holding the coin in one's hand.
Soak in distilled water for a few days, change out the dw then repeat. It can take several weeks to loosen the crud. Also soaking with verdicare or extra virgin olive oil for a few days after doing the dw routine. There are members such as @Pishpash who are magical with cleaning ancients that have great results I just don't know her method
Thanks for the help; I appreciate the advice. I understand that I should get a soft-bristled toothbrush and lightly brush the coin from the center for a while, then find a sharp tool and delicately hit the dirt a little at a time. Is that right? Also, no, I've haven't tried identifying it yet. I was waiting to get the dirt off in order to see it more clearly, but I understand that your method will allow me to identify the difference between a raised feature and a clump of dirt. Also, I don't know what all the different colors are that show up on the surface of these uncleaned coins. The majority of the coin is blue-green, which I assume is the patina, but then there's dark red areas, whitish areas, and dark green areas. I have no idea if I should try to scrape at those or if they're part of the coin now. Honestly, this is the second coin I've identified. My first was a CONSTANS P F AVG on the obverse and "happy times restored" on the reverse (I didn't write the inscription for the reverse and it's to worn to read, haha). It's nearly featureless on the reverse but I got lucky and managed to identify it within five minutes. So I'm in the dark on a lot of the identification methods and websites with the info I need. If you could point me in the right direction, that'd be wonderful.
I did point you right to the identification of your coin. If you go to the link I pointed to in my prior post, (maybe my first), you will see the reverses for the ruler on the obverse of your coin. I believe I have identified the ruler from the legend on the obverse. So I think you can easily pin down the attribution. It is one of the two double victories (angel-looking beings) standing over an altar with a big round thing (wreath?) with some letters inside of it. Go and take a look. You can see enough of your reverse to compare it to the reverses shown there. And down below you will see your ruler. You know your's is right facing and there aren't many - and he has an interesting head gear so you'll be able to pick him out and then you'll know which coin you have. If you want to post another photograph after the brushing, please do. And better than a hand brush, you might get a child's battery operated tooth brush and then use it held at an angle against the surface of the coin sort of glancing it off the surface. But stop after some minutes. You do not want to heat up that dirt. Work for some minutes. Let the coin cool off and your hands too. And then work for some more minutes. Like that. Good luck and have a good weekend.
I stared at the coin for well over an hour and I think I got the obverse narrowed down to two portraits, and the reverse narrowed down to one, but it doesn't match perfectly. I went trough the elimination process twice and it's the only reverse that makes sense. The wings are a bit off, but they come close. I'll attach pictures of the partially cleaned coin as well as the selections I narrowed it down to. The obverses are what don't make sense. For the first obverse circled, the cuirass doesn't seem the right shape and the overall feel is off. The second one looks better to me, but the spear/arrow he's holding doesn't seem to appear on my coin...
Howdy @CopperGenie Does the legend on the obverse look like it says PF after CONSTANTINVS? Your mint is SIS - you can see that below the ltwo victories on the reverse and also the legend on the reverse seems to be VICTORIAE LAETAE PRINC PERP Here is a whole list of coins in this category that you can see and you'll know the RIC number for your coin. Scroll down the page until you get to the part that has the photographs. I think you should find it here, although I did not look because I must do some other things around here. http://www.constantinethegreatcoins.com/sis/ P.s. An hour is not so much to spend on an attribution especially when beginning. They are not all accomplished in one sitting. If you did that on the first one, you may be expecting it will always be that way. That has not been my experience. But I look at it like a treasure hunt and I enjoy it. Try not to let yourself get frustrated if you find you are starting to feel that way. Also, I was wondering, if you don't mind me asking, why have you taken up cleaning of ancients as a hobby? Thanks
The obverse reads: "IMP CONSTANTINVS P F AVG" The reverse reads: "VICTORIAE LAETAE PRINC PERP" I'm pretty sure it's RIC VII Siscia 47 http://www.constantinethegreatcoins.com/sis/47b.jpg I've been a collector for a decade and just this year decided to start cataloging my coins, and realized that I have an affinity for ancients. I like getting the unidentified coin and discovering everything for myself, so I can learn about the history of civilizations. Whether I have to get through layers of dirt or not to get the identification is fine with me, haha. I also just think ancients and medieval coins look way cooler and treasure-like.
Oh! I see now, where you started to tidy up the obverse of your coin. You still have a lot of crust there to get off. What did you do exactly? And I see what you mean about the obverse. While it looks like RIC 47 (the first one listed) the reverse does not look like the one that goes with that obverse. The victory that is leaning back on your coin is not leaning back on the one in that RIC 47. By the way, sometimes you can come across a coin that is not included in the RIC. If you think that it is not included, You can ask our experts here at CT. In that case, I think you want to start a new thread - not about coin cleaning. Make it a question about attribution and whether it is possible that your coin is not included in the RIC. You might like to tidy your coin up just a bit more though, so that folks can see it better. I think what I would do if I were working on that coin is gently lift away some of the flaky pieces that seem to be begging to be removed. Like the piece right next to the ruler's upper lip. And yes, ancient coins are the coolest!
Thanks for telling me that was actually dirt; I couldn't decide whether to leave it or not. It looked to me like I was taking off the "outer layer" of the patina because it was so consistent across the coin. After I clean it a bit, I'll take a look again. I'm working on cleaning another coin at the moment, one with big clumps of dirt that just won't come off haha. I'm trying to soak it first to see if it wettens the dirt a bit and make it a bit easier to clean. As for this coin, I just started to brush it, which got was more off than I anticipated. Then, I picked with a bamboo skewer at clumps of raised dirt until they fell off. I didn't get it all, obviously, but as much as I was willing to take off before I knew the rest wasn't the patina.
