Question on large cents....

[Mr. Mojo]

I have found some large cents in the past two years and the phenomena occurs almost every time. when you dig them out, you can see the detail quite well, or the best possible. After some gentle cleaning, sometimes soaking in Ev Olive oil, they loose the clarity on their detail. It still remains. However, you need to wet the coin to see the same detail. Is there a scientific explanation? FYI just found a 1803 Flowing hair (1/100) that seemed in very good condition. At the end of the day, I could not pick the details out as easily.

[alpha105]

liquid acts as a magnifier.....thats what im guessing causes it. (i know it acts as a magnifier but not sure if its whats causing it to look better.)

[Teeenbean]

Well not sure if theres a scientific name for it but light cleaning at best is all you should ever do 2 a large cent in low grade dug up condition this means water only maybe light bath in club soda for mint state.

[BestAntiquities]

Your problem is a common one with those who clean ancient coins.
Water on a coin surface fools the eye so that broken lines seem connected.
All buried coins are heavily pitted and to make them look nice to the eye one must fool the eye.

Never use electrolysis on a modern copper coin. This makes the coin surface look like the surface of the moon and removes all the protective patina. Such harshly cleaned copper large cents soon oxidize and look more like puked-up salmon.

If your large cent has a nice thin green patina don't clean it. Don't add anything to it--leave it alone.

The biggest trick used to improve nasty dug large cents has been to heat and coat the hot coin with a wax sealer made for antiquities. For hundreds of years bees wax was used. Today more advanced formulas are employed such as Renaissance Wax.

A word of caution--never overclean a modern machine made coin (1700's to date). Just remove the heavy ugly corrosion and then heat (dry it out) and seal with wax.

Once wax is dry buff gently with soft cloth.
Here is a picture of a dug Spanish 2 Maravedis coin that was properily cleaned.
Hope this helps.

PM