The Collaborative International Dictionary of English v.0.48:

Sphalerite \Sphal"er*ite\, n. [Gr. ??? slippery, uncertain. See
   Blende.] (Min.)
   Zinc sulphide; -- called also blende, black-jack, false
   galena, etc. See Blende
   (a) .
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

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.
       [1913 Webster]

WordNet (r) 3.0 (2006):

blende
    n 1: an ore that is the chief source of zinc; consists largely
         of zinc sulfide in crystalline form [syn: zinc blende,
         blende, sphalerite]