I have several 1994 Proof silver eagles in the mint cases. The coins are still in their air tight cases, but I noticed they have toning around the rim. I'm not an expert on coins. Nor am I a hygrometer. I've recently stuck some Damprid in the area I'm storing the coins to deter more toning. If I were to submit these to NGC, would the toning effect the grade? Newb question, thanks to all that reply! Mitch
The toning will not affect the "numerical" grade until it becomes detrimental to the coin.(as far as I know) I could be wrong. Now, if you were to send it to NGC and the toning has a nice eye appeal, you could get a "Star" for the eye appeal. That will usually garner a premium over another coin in the same grade without the "Star".
I have a silver proof medal that the Mint produced for the Bicentennial. It was in an airtite in the OGP, but whoever owned it before me apparently did not protect it from heat and humidity. As a result, the haze turned much darker and etched into the metal. Submitting it to NCS for conservation helped somewhat, but the damage was done. Just be sure to use a good desiccant, and check it regularly. Chris