This is a metalpoint stylus. Metalpoint and silverpoint have been done for centuries using silver, gold, and tin to draw on paper or grounds. I think the tip on this stylus may be a lead alloy. The tip should last a lifetime.
BarryThere is no lead in or on the tip. The reason it lasts "forever" is that it oxidizes the paper rather than leaving bits of itself behind.
Ever pull a bunch of old letters out of a drawer that have turned yellow? Yeah, same principle. Oxidation.
The only wear on the pen itself is from the friction between it and the paper, which would in theory take several lifetimes to have a noticeable impact.
gibbousmoonThat's not 100% true. Specifically: "The metallic tip microscopically scratches the paper in order to oxidize it, releasing microscopic particles, so the tip gets thinner, albeit very slowly." (translation of a comment made by one of the founding members of Napkin in an Italian forum). He also stated that the composition of the tip was changed in 2015 to improve its overall behavior.
gibbousmoonYou've misunderstood. I was referring to the composition of the metal tip--not pencil "lead". AlexGk is correct, a very thin layer of metal is left on the paper, allowing the oxidation.
BarrySo was I. Apparently *you* misunderstood. ;) There is no lead in the metal tip. Neither Pb (which I was talking about, and assumed you were talking about as well) nor pencil "lead" (which is actually graphite).