At 345 grams in mass, this is a large nugget for a pure silver nugget from the Michigan copper district. Often they are mixed with copper to make "half-breeds," and such large and pure masses of only silver are just uncommon. They are mostly from the heyday of the mines in the late 1800s and early 1900s, preserved from the smelters through old collections of miners and mine captains. This happens to be a particularly elegant and dimensional nugget, as well! Joe Budd photos.