I had a question ask by somebody interested in a watch I have for sale. The question is what is the green material around the outer edge of the case in this picture. Any help would be appreciated.

 

As my friend Dr. Venkman would say: "Protoplasm...and be careful not to get any on your suit..."

 

Toxic. Interesting. http://en.wikipedia.org/wiki/Verdigris

 

Thanks. I have looked at that picture many times but it never bothered me.