Just acid-dated some buffalos that had mint-marks but no seen dates. Well, I'm proud to announce that I have owned these for years without actually knowing what I've owned. Since I've gotten back into the groove of coin collecting, and figured out how to acid date the other day, I let them soak overnight in Vinegar and Hydrogen Peroxide hoping that I wouldn't come back to a pile of blue muck: 1916-D 1917-S 1918-D 1919-D Now, if anyone else knows an easier way to date a buffalo nickel without putting it into a bath of acid, please tell me Is there a big coin book that can tell me about various die attributes to figure out how to date without acid?
I've often wished that I still worked at an imaging lab where they did X-ray microscopy. If there's enough difference in material structure to let you acid-restore a date, it ought to be possible to pick that up with X-ray diffraction. From there, it's only a small step to the TPGs offering a "non-destructive nickel-dating" service, with formerly "dateless" nickels slabbed and dated for a "reasonable" fee. And at that point, "acid-dating" becomes another destructive, misguided treatment that we did back before we knew better.
One way to date the nickel without etching the entire coin, if you are using the Vinegar and H2O2 treatment, is to cover the rest of the coin with Petroleum jelly, which would not be affected by the acid. It could be removed with acetone I'm sure. Going to try on a dateless I got out of the last batch of nickels I looked through.
The main point of the soak-the-whole-coin approach is to produce a uniform appearance over the whole coin. Most people think a discolored blob over the date is less attractive than a uniform coin. If you just want to restore the date area, just put a drop of etchant on the date.
