Advice On Cleaning This Stubborn Coin Please!

Why are you wracking your brains out , the coin is gone . There is nothing that can be done to that corroded coin . But For Trying .

I agree, there really isn't any detail left on this coin, but if you want to try an remove encrustation try using some Lime Away and a cotton swab.

Is it silver or bronze? Nothing can be done if that black crud is horn silver. If it's bronze, lime away could work, or you could try electrolysis. IMO, no reason to wreck a perfectly good spoon over this coin though.

Hey there, I'm only one year in on this hobby but I deal with 99% pennies mostly. I have so many that are corroded and have so much gunk I can't even see the coin. I am also a DIY Projects and Natural remedy and products fanatic. On of the products I make is home-made Organic cold pressed extra virgin coconut oil. I use it for my entire body heat to toe and I figured if it's good for my body and doesn't cause harm then why not soak my stubborn coins in it. Well it does work. Not to clean completely but it loosens enough crud to be able to wipe I away or carefully pick off some of it to see the coin. Here is what I do:
Add a teaspoon of oil for each coin to a microwaveable bowl or pot if using the stovetop(3 coins 3 teaspoons, 10 coins 10 teaspoons an so on).
Heat the oil until melted completely if the oil is solidified, if already liquid form heat until warm. This goes for microwave and stovetop heating. (Do not boil or let oil turn brown).
Remove from heat and gently place coins in oil flat either side up it doesn't matter.
Let coins sit in the bowl or pot until oil turns to solid state. If it is warm enough at you location that the oil stays as liquid for more than 3 days move to a cooler location and let set until solid again. Not a hard solid just the mushy white oil (do not refrigerate to form solid oil it will harden too much and will speed up the process too quickly thus wasting your time).
Once oil has thickened to mushy oil State flip coins over one by one every day for 2 weeks. (I know It will be difficult to remember to o
Do this daily just try to remember it is important if it's on both sides. If it is only one side just leave it as is.
After 2 full weeks remove one out at a time wearing gloves (I use the go the vynil or nitro gloves I "Borrow" from doctors n dental offices lol.
Also have some qtips or cotton balls or pads, a ceramic or metal bowl with almost too hot to handle bottled or filtered water so the calcium deposits are filtered out.
Remove the coins one by one from the oil and gently placed them one-by-one flatly in the bowl of water and let the coins sit there for 1 hour. the oil on the coins will prevent any damage to the coins from the water such as rusting or discoloration.
Then again remove the coins one by one cleaning the coins with the cotton very gently in a circular motion one at a time.
you may have to repeat this process multiple times to get the results that you're looking for and keep in mind that this is not a 100% cleaning method it will remove the built-up Grime on the coins I will post pictures of my before and afters so you can see for yourself.
remember to be gentle with the coin do not rub to hard if it's stubborn repeat the process as many times as you have to you don't have to go to full to weeks each time just very first time unless you have the patience to do so. But after the first time you can do it daily, every other day, you could do whatever you want just make sure the oil is warmed to melt, water is warm and circular motions with cotton.
If the oil gets dirty formt then Coin or coins, start a new batch and continue on.
Buff coins with soft plush micro fiber for cleaned good coins and protect with whatever holders you use.
Good luck and let the me know how it turns out for you. I'll post to pics in this post in an few

Hopefully the member FVRIVS RVFVS will chime in? He is a wizard at cleaning coins and is incredibly helpful to new members. He is always willing to share his methods and expertise to ensure that our hobby grows by sharing his knowledge with new collectors.

Good grief !

Claudius I agree that is what mainstream thinks ... but I have seen fakes that were so well marinated that no on would believe they were fake. Also remember some collectors including me love the unclean natural looking coins vs cleaned one's and forgets are aware of it.

This coin is definitely too far gone to get anything great out of it - the green stuff is corrosion underneath the patina. It probably means that the whole patina will be unstable, so caution is needed. The best thing to do is to exercise a very healthy amount of patience - for really solid muck like that, it can take a long long time. It doesn't look too 'mineral-y' so I reckon it will come off with a couple of years in oil. The coin might also disintegrate when that muck is removed, but it wont be worse than what you have currently.

My advice: Wash it well in soapy water with a toothbrush to remove all traces of oil currently on it, then wash it several times with distilled water to remove the soap. Bake it in the oven at a low temperature for an hour or so to drive away all the water, then place into fresh olive oil and tuck it away somewhere you will forget about it. In the future when you next stumble upon it, you can see if there is any change. There might be no change at all, it might come out clean. Personally, I wouldn't bother with it and I'd keep it to use for practice with new cleaning techniques. Time consuming cleaning projects on damaged coins is worth it for a rare one, though.