DurocShark
Member
According to http://www.plastiquarian.com/vulcanit.htm :
Hmm.....
Mouldings in vulcanite (hard rubber) were exhibited by both Hancock and Goodyear at the Great Exhibition of 1851.
The material is most commonly black in colour and has been used to make combs, buttons, vesta cases, jewellery, fountain pens, pipe stems (both plain and decorative), musical instruments, etc.; it was also widely used as an electrical insulator and for chemically resistant linings. A reddish colour was used for denture plates until superseded by celluloid and acrylic. A reddish material rippled with black was popular about 1930 for fountain pen and pencil barrels.
It was originally based on natural rubber but since the 1930s has been based wholly or partly on various synthetic rubbers.
Hmm.....