Tetradymite
Pronunciation : Tet*rad"y*mite
Part of Speech : n.
Etymology : [Gr. (Min.)
Definition : Defn: A telluride of bismuth. It is of a pale steel-gray color and metallic luster, and usually occurs in foliated masses. Calles also telluric bismuth.
Source : Webster's Unabridged Dictionary, 1913