Vulcanite is a hard, dark, shiny material made by adding a high percentage of sulfur to natural rubber and heating it, essentially a super-hardened rubber (also known as Ebonite). Discovered by Charles Goodyear, it was used extensively in the Victorian era to mimic expensive materials like jet and tortoiseshell for jewelry, combs, and buttons, but also for electrical insulation, pipe stems, and fountain pens due to its durability, workability, and insulating properties. It's known to oxidize (turn yellowish/greenish) and smell of sulfur when exposed to light/moisture, distinguishing it from true jet