Is it acceptable to clean ancient coins?

[Deleted User]

I collect mainly US coinage. I do not collect ancients. I do like them and several of the 20 I have will stay with my collection.
I have watched some YouTube videos and learned about ancient coin restoration.
I have take two coins and cleaned them. I think they looked terrible before and much better now. I see no reason to clean any silver coins but the copper, bronze and other various metals I have learned about including lead coins become heavily oxidized.
I literally used a microscope to clean these coins.
What are your thoughts?
Before


After


This is the only image I have of before with this coin. This is the result of 2 hours time-



One more-

Sapyx

Most ancient coin collectors will say "you have ruined your coins". You have certainly reduced their value.

First off, we should begin by saying "all ancient coins need cleaning once". That is, when they are dug up after being buried for 2000 years, most ancient coins look like little green rocks. It takes patience and skill to turn the little green rock into something resembling a coin. There is a school of thought that says a coin should only be cleaned up to the point where it becomes identifiable, then cleaning should stop. Most collectors don't subscribe to quite that extreme a philosophy, rather, reducing the coin down to a nice clear patina.

Your coins were already "cleaned" in this fashion. They did not need further cleaning.

You have stripped away the patina, bringing the coin down to bare metal. Most of the surviving detail of the coin, the "original surface", is preserved in the patina, not the bare metal.

Now, on occasion, an acnient coin does need further treatment. If it develops the kind of contagious corrosion called "broze disease", it will need treatment to prevent the corrosion from spreading. Your second coin has the powdery green appearance of bronze disease, but your second coin confuses me because that's a silver tetradrachm from Ptolemaic Egypt; it's not supposed to be bronze. If it's bronze then that's probably a "tourist fake" counterfeit.

[Deleted User]

Thank you for commenting. I understand what your saying as far as the cleaning goes. Ive only done it to a couple. One person here told me my coins really had no value that is to say that all of the coins I posted in my thread added up to under $100 and another told me they do at a much higher value.. I didnt touch any of the silver coins except #2 while not realizing it was silver. It was dull and black. I believe it has a very attractive look now and was not cleaned harshly. I have silver coins that have green on them from storage issues.
Are you suggesting these coins are valuable? Now I am growing concerned. BTW I have been looking on ebay to try to locate my coins to match them up and while doing so its doesn't appear that any of them look black and dull. They look like mine or even more "polished" which I didn't do, I just got the crude off with a toothpick and elbow grease.
It's not bronze it's silver just as it looks I believe anyway. It was covered in hard sand or clay which is primarily what I removed.
I do not dispute your opinion in any way at all. I watched multiple YouTube videos that discussed proper ways to care for and conserve ancient coins to prevent further decay which was my primary goal. That and to also help with the eye appeal as they looked dull and dark. I believe the collection I bought which came with about 500 additional coins had been stored since 1960 and haven't seen the light of day for 60 years.

[Deleted User]

This appears to be a match and I do see some green on this coin. I may be wrong.