Does Grading Change Over Time If Stored Properly?

Thank you all for the help. I obviously know nothing about coins. I did notice a whole bunch of the gold coins had random spots of toning, so it had me worried. I'll try to take a few pictures tonight to show what I'm talking about.

TCL963, this would be great. You are doing a great job for your mother and yourself in doing the research. Post away.

Here's another example. Again, not good pics, but the second one looks really dark and splotchy in person, especially around the arm. Both PCGS 69, but looks completely different.

Thanks for the response. That makes me feel must better.

I would consider this discoloration as undesirable. However, since the Liberty doesn't bring much if any premium over melt, it won't affect the value. The FDR coin might have a modest premium, but it is not rare by any means.

If you are looking to sell them DO NOT take them out of these slabs, just sell them as is, and hope for the best.

However, I do view this as further proof that buying PCGS slabbed gold is a risky proposition. I have seen terribly ugly red toning on slabbed First Spouse coins that is unlikely to have been there when the coin was first slabbed, or it never would have been submitted for grading. PCGS has allegedly re-engineered its slab, but I am still skeptical.

Thanks everyone. He has a bunch of different gold coins and it seems to only be the ones that have more of a raised and textured design that are affected by the toning. There are quite a few that still look perfect.

iread an article about a Lincoln Cent (zinc composition) braded MS 70 by one of the top grading services) that sold for many thousands of dollars at an auction.. it later deteriorated in the encasement.

i did not ever find out the putcome of the value/deterioration value. but my opinion is that YES a coin can change grade/value even after being graded and encapsuled in a good holder.