From Greek "sphaleros", treacherous, an allusion to the ease with which dark varieties were mistaken for galena, but yielded no lead. Sphalerite, also known as Blende or Zinc Blende, is the major ore of Zinc. When pure (with little or no Iron) it forms clear crystals, usually red (known as Ruby Blende), but as Iron content increases it forms dark, opaque metallic crystals (known as Marmatite).
Colors are Yellow, light to dark brown, black, red-brown, colourless, light blue.
Mined in USA, Canada, Australia, Kosovo, Austria and Italy.