Found this nickel in a mint roll. It has a brassy color to it and I was wondering if this is what is referred to as copperwash and how it comes about?
Since you report finding it in a mint roll I suspect that yes it is a copper wash/sintered planchet coin. It often happens during the annealing process, when planchets are heated prior to striking. In simple terms, leftover copper dust in the annealing chamber is deposited on a planchet and literally baked onto the surface. It is also thought that it can happen during the planchet washing process when excess copper particles in the wash solution can adhere to a planchet.
i don't suppose it could be determined if it's not from the mint directly... i found these two nickles in the same roll once.
Thank you for the info. I had to look up the term annealing and now understand it better: (nl´ng) (KEY) , process in which glass, metals, and other materials are treated to render them less brittle and more workable. Annealing consists of heating the material and then cooling it very slowly and uniformly; the time and temperatures required in the process are set according to the properties desired. Annealing increases ductility and lessens the possibility of a failure by relieving internal strains. The process, also called hot working, was known to the ancients.
Sometimes it can be, but from looking at that nickel I'd guess it was the result of toning from being in the ground.
