Definify.com
Webster 1913 Edition
Tetradymite
Tet-rad′y-mite
,Noun.
[Gr.
τετράδυμοσ
fourfold. So named from its occurrence in compound twin crystals, or fourlings.] (Min.)
A telluride of bismuth. It is of a pale steel-gray color and metallic luster, and usually occurs in foliated masses. Called also
telluric bismuth
.