Argentite

[ɑ:dʒәntait]

(noun.) a valuable silver ore consisting of silver sulfide (Ag2S).

Typist: Mag--From WordNet

(n.) Sulphide of silver; -- also called vitreous silver, or silver glance. It has a metallic luster, a lead-gray color, and is sectile like lead.

Typed by Hiram