Does anyone have any explanation for this type of toning? I have never seen it on any other country's coins except Italy. Apparently original, as there are many in slabs with this type of tone. This is a rather extreme example, other coins with the same tone sometimes have a much lighter "ring" and the ring varies in width. Interestingly, it doesn't matter what size the coin is, I have seen it on crowns all the way down to the smallest silver issues the Rome mint struck. Are these all from the same source or collection?? Thanks for any ideas on it.
The only thing that would come to mind is a type of coin packaging that either the mint used, or was popular with collectors in Italy. I have seen some manila envelope toning patterns before, more prevalent on larger coins, that were caused by the tightness of the envelope allowing air to only touch the outer ring of the coin. Hard to describe online, but if I had a pen and paper I could draw it. Not saying that is it, its just my only thought.
Here's another, from a recent Heritage auction...,, http://coins.ha.com/c/item.zx?saleNo=3019&lotNo=25007&lotIdNo=21579 I purcahsed another just like it, but without the tone or ring. Given a choice, I always go for white coins unless the tone is spectacular.
It's a type of tab toning. They used to make a cardboard coin holder (see below), sometimes for single coins, sometimes for sets. They came in many different styles, shapes and designs. And those holders resulted in toning patterns similar to what you are seeing on these coins.
