ebonite

n. vulcanite, hard black material (mix of rubber and sulfur)

This article details a type of plastic, for the manufacturer of bowling balls, see Ebonite International Ebonite is one of the earliest forms of plastic. A hard, rigid and shiny resin, it was intended as an artificial substitute for ebony wood. It is actually a very hard rubber first obtained by Charles Goodyear by vulcanizing rubber for prolonged periods. As a result, it is about 30% to 40% sulfur. It is often used in bowling balls, smoking pipe mouthpieces, fountain pen nib feeds, and high-quality saxophone and clarinet mouthpieces. It is alo commonly used in physics classrooms to demonstrate static electricity.
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Noun
1. a hard nonresilient rubber formed by vulcanizing natural rubber
(synonym) hard rubber, vulcanite
(hypernym) rubber, India rubber, gum elastic, caoutchouc

n. ebonite, vulcanite, hard black material (mix of rubber and sulfur); hard and inelastic rubber made by the vulcanizing of natural rubber with sulfur

n. ebonite, vulcanite