Sphalerite \Sphal"er*ite\, n. [Gr. ??? slippery, uncertain. See Blende.]

(Min.) Zinc sulphide; -- called also blende, black-jack, false galena, etc. See Blende
   (a) .

Source: Webster's Revised Unabridged Dictionary (1913)
 

Blende \Blende\, n. [G., fr. blenden to blind, dazzle, deceive, fr. blind blind. So called either in allusion to its dazzling luster; or (Dana) because, though often resembling galena, it yields no lead. Cf. Sphalerite.]

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

Source: Webster's Revised Unabridged Dictionary (1913)