Dictionary entry

Tetradymite

Webster's Dictionary 1913

Tet‐rad″y‐mite (?), n. [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.