Source : Webster's Revised Unabridged Dictionary (1913)

Gothite \G["o]"thite\, or Goethite \Goe"thite\, n. [After the
   poet G["o]the.] (Min.)
   A hydrous oxide of iron, occurring in prismatic crystals,
   also massive, with a fibrous, reniform, or stalactitic
   structure. The color varies from yellowish to blackish brown.

Source : WordNet®

goethite
     n : a red or yellow or brown mineral; an oxide of iron that is a
         common constituent of rust [syn: {gothite}]