Coinsandcanada.com

I have these 1952 nickels, both seem different. 1 is shinier then the other and appears to have rusting on rim. 2nd nickel is dull and no rust. Would these be a chrome vs missing chrome??

The '51 and '52 nickels were steel with .0127mm nickel & .0003mm platings. It doesn't take much to wear down the shiney chrome and/or nickel. Any rust is moisture getting to the steel. Your "gray" coin could just be environmental

So environment removed ALL chrome, hard to believe.

But true.
Just one of the reasons grading companies no longer certify them.