I absolutely agree. Beautiful pristine surfaces are lovely, but they can also turn on you (literally) and then you have something much uglier than a stable XF that will never change.
I remember my local dealer lining up morgan dollars to show me how some had been cleaned. With some nice uncleaned MS coins, when you placed a cleaned one next to them you could see a slight difference in color and luster.
Here is a Barber Quarter that I purchased raw a few years ago and had graded that came back cleaned. I think the cleaning on this coin is harder to see than the Barber Half shown above but the luster just doesn't look right.
If a "cleaned" coin is allowed to age, mellow and oxidize. could it ever pass for an un-cleaned coin?
Paul's coin shows classic harsh cleaning in the fields on the obverse--look at the scrubbed areas to the right and left of the face--between chin and forehead and behind the cap--there is evidence of scrubbing there.-- hairlines and abrasion marks. When you see that on a coin, it is evident that it is beyond a simple dip. Shame, as it is an attractive coin, but it was heavily cleaned.
Are we talking about just cleaning in general or are we talking about detecting what the market considers to be uncleaned? There is a school of thought out there, that some particular denominations of 19th century and even some 20th century coins have almost all been cleaned at some time. In fact if you read the NGC grading guidelines on Capped bust halves they even state that some halves that been cleaned and "retoned" can be certified with a grade. So in my opinion determining whether a coin has been cleaned or not can be somewhat subjective, especially if the cleaning occurred 75+ years ago. With mint state silver the obvious signs which have been stated are impairment to the luster and surface irregularities like hairlines or inappropriate color. If the coin is truly uncirculated the surfaces should reflect that. One thing you can do is go on eBay and look at coins in holders labeled "improperly cleaned" versus problem free. Ultimately you just simply have to train your eyes to it, and it may take looking at quite a few coins before you develop that connoisseur mentality.
Ugh that Barber is a crying shame. I think Barber halves have suffered just about the worst attrition of any type due to cleaning. I imagine a coin like that was probably purchased sometime in the 50's or 60's for a couple bucks and the owner then gave it just a little rub thinking he or she was doing the coin a favor. It pains me to see how many Barber halves are like this and there are sooo many of them floating around on eBay with outrageous prices and no buyers.
Here are some examples of cleaned or over-dipped coins. Lightly cleaned on obverse only. Harshly cleaned PCGS says these are cleaned
You can read these short post that have some good insights. But you need to spend several hours viewing problem coins. The best way to do this is search graded coins and zoom in on the details graded ones to see why the TPG graded it that way. Do this on ebay
MY goodness! that is an awesome coin. Does NOT looked cleaned to me at all. Why is it that way? I would like to have one like that.
With modern coins more so than with old even a single wipe is often enough for the coin to get the harshly cleaned designation. I'm thinking I can see a couple wipes on that coin - above the date and onto the bottom of the neck, and on the rev close to the rim from about 3 o'clock to 5.