This 1914 ANACS Lincoln was bought about 12 years back as part of a lot of common XF-AU coins. I bought the coin in question as an AU and an unattractive example at that. It had some substance on it from handling. I used the MS70 and it did improve the color though bluish and removed whatever the contaminate was on the surface. I still view it as a AU regardless of the holder the coin is worth less then a nice well struck AU example would be though its perhaps the most common teen cent in mint state. The coin remained stable a year or better , exactly as it is now. It was submitted to ANACS about a decade ago. The coin remains stable and still is a cleaned AU IMO the coin has pinkish in the center still and is a low end strike even for 1914. I can not agree the coin has no rub under bright light it sure looks like it does , along with worn dies resulting in the poor obverse strike. ANACS says MS63. I love ANACS so this is just one of those look at the coin not the holder post no one is 100% all the time.
Wondering about this myself. The metals used in coins is usually not reactive towards bases(I wonder what MS70 would do to an Aluminum coin?), but WATCH OUT for acids. BTW, coin dips are highly acidic.
I agree with your AU assessment. I have used MS-70 with varying success on some proof coins. Though it is acidic, if you dilute it and dunce the coins off afterwards, you can get some good results.
Sorry, it is not acidic, it is anti-acidic...basic. Both can be considered corrosive, but basic is a high pH while acidic is a low pH.
