How to make a darkened ancient silver coin a bit brighter?

Hello, I recently acquired this Hadrian denarius,




Obv: Emperor's bust right.
Rev: Clementia holding a doughnut, over a trash bin.





I believe this patina on it must be a very old re-toning or possibly the original patina from out the ground. This patina covers most of the coin, including the edges and looks like a medium light charcoal color, the only areas that are lighter are just the highest surface areas on the coin.

Being an addition to my five good emperor's collection, I want this coin to stick out a bit more with my other coins in the set.

Is there a specific technique or tips on how to remove a little of that dark toning without overdoing it and making it too shiny? I would like to avoid dipping the coin because I feel that will totally ruin it.
Is there a simpler process of remove "some" of the dark toning from the coin with baking soda or something or do people usually dip and retone to get the finish I see on a lot of denarii in the market today?

 

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It looks good as is IMHO. I have a couple of denarii where someone has removed all the "patina" (tarnish). I do not like it. I would prefer the tarnish. I have a JC denarius that is nearly black and it seems to get darker every time I look at it. But I prefer that as to a shiny example:

 

As per your photogs, it looks fine the way it is........I'd leave it be.

 

It's actually a bit darker than it is in my photos. I have some mixed feelings about this type of toning, the dealer I purchased it from definitely made the photos brighter, so it was a little darker than I expected. Most of my denarii have a re-toned silver finish that I love because it is not too shiny nor dark. I feel like I have to look at this coin harder to get all of the details.

 

Sodium thiosulfate is magic for removing horn silver, and would probably remove much of the toning too.

 

I would leave it the way it is as well. If you clean it, the value of the coin should you later decide to resell it will definitely be lower. Plus I think it looks great the way it is. Great coin!

 

Thanks, I guess I will decide what to do for this piece but this toning isn't something I would consider attractive in my eyes, it might be all preference but imo a nicely re-toned coin with good details showing would fetch a higher resell price than something too dark. I will see my options, should I decide to remove some toning I will be looking into the most safest method, removing the black toning a little at a time to avoid overdoing it.

 

Wow, I would leave it as it. Nothing wrong with it.

 

Acetone can always lighten toning, if said toning is actually some dirt or something. I like acetone since it will never hurt an honest coin, but beware sometimes it will show where someone dishonest cheated you with fake patina. Usually they come out of acetone the same or a little lighter. A quick dip in purified water after is good too, but I have never had any issue with acetone. Always use pure acetone from the hardware store, and it evaporates completely and quickly.

 

I know what you mean. In general, I prefer toning with more of a contrast. Still, I'd hesitate to experiment on anything but a really inexpensive coin. (which yours may be, I don't know.)

 

Yes I will be trying acetone tonight first, I always give my coins an acetone bath as soon as I get them home. Hopefully it will lighten my coin little. So far I haven't had any bad surprises after the bath haha.

I have also found some areas that might be some kind of deposits in the legend/inscriptions, or could be horn silver.....

 

I think it looks nice personally. I detest shiny white coins, but know they need to be cleaned after found to get rid of horn silver and other reactions.

 

Please don't touch the coin. You will literally ruin it IMHO.

The toning is beautiful and desirable in ancient coins.

 

This is an excellent patina, and I would advise to keep it in the current state.

 

But like I said the toning is actually darker than it looks in the photos, I wish I knew how to take decent photos of coins. If there is a way to just brighten it just a teeny bit the details will be more apparent!

 

black is beautiful...

 

Sell it & buy one that suits your taste better

 

Good idea but I like the Scotch Brite idea better

 

I'll repeat here what I've answered in a private message of @ArtDeco. This is a coin that would not improve with sodium thiosulphate, in my opinion.

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I've actually posted a more detailed walktrough, which can be downloaded at my researchgate profile: https://www.researchgate.net/project/Ancient-coin-restoration

While most coin restorers don't share their methods, I decided to share some of my techniques to save coins from unexperienced collectors.

Regarding the denarius of Hadrian which you posted: it really is fine as it is. The patina, even though it may be darker in real life, is the process of the coin being deposited in the ground over the last c. 1800 years. There are no horn silver deposits, though there are some earth deposits on the obverse.

If you really insist on brightening the coin, there are a few options:
1) thouroughly rinse the coin under flowing tapwater, by rubbing the coin between your thumb and finger. This will probably remove the (darker) earthen deposits on the obverse, and the (mild abrasive) rubbing will slightly lighten the patina

if unsatisfactory:
2) apply a very minute amount of baking soda (NaHCO3) and repeat (1).

if unsatisfactory:
3) repeat 2, but now rub a small piece of aluminium foil. This will cause a redox-reaction with the NaHCO3, which will remove the silver sulphide (= the black patina).

Note that baking soda is abbrasive and will, if rubbed for too long, polish the coin.

Having said this all, remember that there are many cleaned coins on the market, and only a small hand full have the desired black patina your coin has - many ancient coin collectors will pay a premium for the patina your coin has.

 

Yes, definitely leave your coin as is. It has a really nice, even patina.