Toning Question on ASE's

silverandvinyl

Are there certain areas on the obv.or rev. (not only ASE"S) where a coin will start toning first?I just pulled out 3 1997 ASE and they are toning around the edges and then I found 1 2002 ASE which was toning at a angle from the bottom left to the top right.This on I had in a flip while the others were in air tights.The flip one just does not look right.Could the flip cause this?

gsaguy

Silverandvinyl,

I would suspect that to some degree it's a matter of the toning medium. For instance, an evelope would likely tone in a slightly different pattern or on different places on the coin's surface, than say something like a cardboard holder.

Basically, as I understand the toning process, sulfur molecules in the medium, disengage and settle on the coin's surface and react with silver molecules. Since I believe that sulfur molecules are heavier than air, I would assume that gravity would cause more of them to settle in the coins fields and crevices of the devices. I suspect that's why you often (but not always) see a difference in colors from high points to low points on a coin.

A coin held in place in a cardboard holder would likely tend to tone from the outside rim inwards. An envelope toned piece might exhibit more even toning across the surface.

Having said all of the above, I'm not a chemist. This is just my understanding of the progression of the toning process. There are other board members who understand the chemistry much better than I.

Good question and hope I helped.

GSAGUY

P.S. I like your handle.