(1):

(n.) A general term for some minerals, chiefly metallic sulphides which have a somewhat brilliant but nonmetallic luster.

(2):

(n.) A mineral, called also sphalerite, and by miners mock lead, false galena, and black-jack. It is a zinc sulphide, but often contains some iron. Its color is usually yellow, brown, or black, and its luster resinous.