Nifty puzzle. I'm inclined against the finial idea because the item is so smoothed it doesn't have much decorative aspect from any distance. It is so uniformly smoothed, I tend to think it was a stopper, maybe for a large crockery jug, also the way the end is tapered just the way a stopper would be. If it is not magnetic, it could be lead; people weren't sensitive to its toxicity years ago. I remember my dad melting lead on the stove to pour into a bullet mold, just for sport, which may be what happened to my mathematical aptitude and SAT test scores in math.