Murinite

Murinite is a material native to planet Rigel IV.

The Hill People of the Argus River region on Rigel IV used murinite to make the handles of the knives which they used. In 2267, one such knife was used to perform several murders on Argelius II. (TOS episode: "Wolf in the Fold").

Murinite could also be carved to create name tags. Telsk, a receptionist at the Bureau of Interplanetary Affairs in 2293, had a tag carved out of a block of murinite. (TOS novel: Crucible: The Fire and the Rose).