Chemical and structural analysis in industry is very advanced in serious scientific work. I'm sure both markers, microscopic markings, and chemical traces in the parts per billion, can be found with the proper equipment. Whether it is economical or not, I can't answer. But when you start to understand the micronization of the latest waffers in CPU's for example, I'm sure that rivals anything that dipping can do, and there is serious quality control in those waffers. This is largely besides the point. As Doug and others point out, the market allows for dips which have minimal affect. I'd just say that if they want to find the dipped coins, they can, and I'm pretty sure for coins reach nearly 100 years old or greater, that even more than 95% of the MS62+ coins have been dipped. The old time collectors dipped coins as a matter of normal activity. Ruben
http://www.conservationresources.com/Main/section_31/section31_03.htm Well, according to this at least, it is a reducing agent. Ruben
In a way, I'm real happy I never caught the chemistry " bug" . Someone would get hit on the head as I throw my coins out the window.