Here is one of my newest purchases. Please guess the grade; bonus points for those who can guess the composition. Note: what looks like scratched on the bottom right of the reverse is on the holder Hint: it is not AT!
Here is the grade: MS 69 Composition: niobium Reason it's not AT (well at least not what we think of as AT): it was made this way originally; the niobium was intentionally anodized to form the colors (it is similar to what the Austrian and Canadian Mints due with their niobium series). Here is a brief explanation of anodizing niobium: https://www.riogrande.com/Content/Bath-Anodizing-Niobium-HT-psd
Fair enough, but really, how much more "artificial" can toning get? Maybe I'd be more at peace with the whole AT/NT drama if we moved to using the term "improper toning"...