I got a batch of old dealer coins on eBay, not sorted , not attributed and this little fellow winked at me. It is an Alexius Follis formally known as a Anonymous Follis Class J SBCV-1900 21mm and 5.1gm It was minted between 1081 and 1092 AD These are rarely seen not overstruck so it was a very nice find. Obviously it needs to be cleaned. I am going to put into distilled water but I wanted the boards advice on cleaning so I do not ruin this fellow. The cross side is really eye catching.
I usually always start with a dry brush with a cut-down toothbrush. Many times this knocks off most of what will come off without more aggressive methods. This is usually the safest approach as well. Most times, I’m satisfied and stop after the dry brush and don’t even soak many coins anymore.
I don't clean coins anymore after ruining some good ones . Go easy on this coin since the obverse is almost a ghost image already & raw metal is visible on both sides of the coin. As you point out, the reverse is still attractive .
Thank You @Orange Julius for the reply, I am looking at this under a magnifying glass and I do not think I have ever seen one with so much detail in it. It is a very rare coin to begin with. I have the tools just not the skill. I own a microscope , several brushes and pics but my results in the past , well I was not patient enough and I over cleaned.
I agree on the go easy part but I have never seen so much detail on the obverse, for this coin, The crosses have their dots , Christ still has faint face detail. Right now the gospels have a M on it, not sure if that is correct.
Cut-down toothbrush and distilled water to see what it looks like. VerdiCare if you can get some from @BadThad
I would simply apply Verdi-Care to neutralize the green oxidation and to apply a protective coating. I wouldn't do anything more than this.
As you don't have the experience and as this is a very rare type, I would suggest to not try and clean it, apart from doing something about the green stuff if it is bronze disease. Bronze/copper coins rely on a good patina, and patina can be ruined very easily with cleaning. I find silver to be less of a risk when it comes to cleaning, but bronze is not so forgiving.
I agree that it is best to do little unless you are 100% sure of your skills. That said, brushing with a toothbrush should do no harm to any coin. The only exceptions being where the surface is already crumbling - the dread green powdery surface - or where a poor quality fake patination product has been applied. Those are also generally the only types that might suffer from some normal water. If you have concerns about either "bad-surface" scenario above, you can do a few things before using the toothbrush: - rub with your thumb and then check thumb for stains and coin for any bare metal being revealed or flakes coming off, - repeat with a cloth, check cloth and coin, - brush gently with a normal toothbrush - for a normal toothbrush you can brush when the coin is dry, - brush with a stiffer toothbrush - i.e. the bristles trimmed down to 1/2 length with scissors, this can be done wet or dry. At this stage a bit of spit (I know, gross!) or even normal dish soap can be used - as long as you rinse with plain water, or better yet distilled water after. While these steps are safe on almost every coin, they also frankly do little to remove anything but surface dirt, and often won't remove the dirt that has been on for centuries - (that is because such dirt often begins to chemically bond with surface corrosion products, but that is another story). Another idea that is just as harmless but can really assist, is to use a silver-bristle brush. These are like brass brushes but the bristles are made of silver and so much softer. They are hard to find - I bought several in person in Europe years ago but haven't been able to find a supplier online - and expensive - in the 20 Euro range due to the silver content. I have used them on thousands of coins and never seen any damage - unless, as above, the surface is already cracking or powder. But be careful to find brushes with silver-bristles - not/not simply brushes advertised for cleaning silver, which are often soft brass. SC
The best I would do is to use Verdi-Care as cleaning is best left to the pros. That is a lovely coin for the type and those are usually found in much worse condition as you indicate. Congrats!
Thank You Ram, I knew it was a nice find, I found several treasures in the batch but I went back today and rechecked because it had several from the Anonymous follis series , couple of A1's , A3's and couple of Class I , a nice class G and and this a worn Class K.