noun
vulcanite; ebonite
A hard, black rubber material made by vulcanizing natural rubber with a high sulfur content. Used for electrical insulation, combs, and mouthpieces.
硬化ゴムは電気絶縁体として使われる。
Vulcanite is used as an electrical insulator.
このパイプのマウスピースは硬化ゴム製だ。
The mouthpiece of this pipe is made of ebonite.