The Collaborative International Dictionary of English v.0.48:
Vulcanite \Vul"can*ite\, n. Hard rubber produced by vulcanizing with a large proportion of sulphur. [1913 Webster]WordNet (r) 3.0 (2006):
vulcanite n 1: a hard nonresilient rubber formed by vulcanizing natural rubber [syn: hard rubber, vulcanite, ebonite]