Cleaning Silver Coins

P.S I have just read somewhere its best not to clean them as they become more damaged. Would most people agree with that statement?

Kind of depends on the coin. If not a valuable one, there are many things y0u could do. However, if valuable, cleaning might well ruin some of the value. For example regular Jewelry cleaner from most department stores would work but on valuable coins that would be considered cleaning and deteriorate the coins value. Really odd about cleaning. If you clean an old oil painting or your car, no big thing. If you clean some old furniture or a coin, ruins the value.

As a general rule,never clean coins. Post a photo of your coin so we can see what's going on.
John1

Too easy: Don't clean it.

That coin looks great to me. I'd never consider cleaning it, and would be happy owning it "as-is".

Ah, an ancient coin. There are several differences between the treatment of an ancient coin, compared to a modern coin.

First off, There's no such thing as an ancient coin that's been kicking around in people's houses or collections for 2300 years. Every single ancient coin has been dug up out of the ground some time in the last few hundred years or so and all the non-gold ancient coins thus found would have been "cleaned", usually cleaned in a way that a collector of modern coins would consider to be "bad" - perhaps with acidic cleaner, or electrolysis, or the careful scraping away of concreted debris with a diamond-dusted dental tool. Cleaning ancient coins is a necessity; the only debate among ancient coin collectors is "how much cleaning is too much" - there is a school of thought that an ancient coin should only be cleaned up to the point where it can be fully identified, and any cleaning beyond that point is unnecessary and redundant. Most collectors, however, want their coins to at least look like coins rather than little green rocks.

Second, such coins, after being cleaned, are often re-toned to make them look more attractive. Nobody wants to buy an ancient coin that looks like it's been polished. An off-the-shelf compound called "Deller's Darkener" is a sulfur-petroleum jelly mixture designed to be smeared onto a silver or bronze object to make it darker.

Third, ancient coins do not need the same level of preservation that a modern mint-state coin does. It has already survived 2300 years without your help, and will likely survive many more millennia unless you (or its future owners) decide to destroy, deface or otherwise do something ill-advised to it.

That being said, I would agree:
- This coin does not need cleaning. It's toning is what would be considered "normal" or "market-acceptable".
- It likely will not darken any further, or spread, unless it is deliberately exposed to darkening agents such as sulfide. Keep it in an airtight container and away from sulfur-containing substances (such as rubber, yellow paper, or the fumes from cooking eggs or onions) and it should remain in this state for at least several centuries.