the 69 may be dipped in mercury, i advise not to handle as the metal can be readily absorbed into your skin.
Why would someone dip the coin in Mercury? Shy of a science experiment does it serve any purpose in the coin world?
I do not think it was mercury due to the way mercury bonds with copper and other metals to produce amalgams that are relatively resistant to wear, whereas, the science experiment using copper cents to plate with zinc is not as thick nor resistant. I vote the zinc plating experiment. Done by thousands of chem stud. each year.
