Well, as far as slabbing a toned coin, if they feel it's artificial toning, it won't get graded normally. It's considered damaged. If it's considered natural on a worn piece, I don't believe it should be able to change the grade. If it's an upper grade UNC it may well impair and/or enhance the grade depending on luster remaining.
Really, the only way to discuss coin toning is with specific examples. And in the end, when you send your coin in to get graded, it's just some guy on the other side of a desk that gives his opinion. Especially if it's a common coin.
I do believe the PCGS grading guide goes into toning in some detail. If you can get your hands on the book, it is a good read.
If you want to see some wild natural toning on silver, check out the #1
Seated dollar collection. Something like the legend, or Heritage collection, I don't really remember. I'd google and link it, but I'd get smacked. lol
(It's the Legend collection)
Edited by linxlvr
12/12/2012 7:35 pm