ebonite

Ebonite was a brand name for very hard rubber first obtained by Charles Goodyear by vulcanizing rubber for prolonged periods. For vulcanizing rubber he received patent number 3633 from the United States Patent Office on June 15, 1844. Besides natural rubber Ebonite contains about 25% to 80% sulfur and linseed oil. Its name comes from its intended use as an artificial substitute for ebony wood.