1) can the color be because of being more copper then nickel or. Did the mint make polished.
The coin picked up color from its surroundings. Often coins that spent more time in an area with sulfur, they turn yellow in color. Not a premium for this. 2) Theres a small black line on Monticello building 2nd floor arc. How does this occur and why?
I'm not seeing the mark from the image provided. If you are referring to the line from the building upwards, that maybe just a fading stain on that area?3) the letters around on obverse and reverse are all crisp letters. As if bold & strong. It really is a super good looking coin?
That is because of the earlier die state of the coin. When the coin was fresh, it would have been a nice find, But as the coin looses it bloom of youth, it becomes just spendable change. Look at a local coin shop for a mint set for that year and note how the cello protects it, or as it ages, turns the coin to a new color.Rainbow toned coin on top image.


Silver tarnishes and turns more interesting in color, or worse in color.




