title: Siderogel
text: # Siderogel
  
  Siderogel is an amorphous mineral (a mineraloid) consisting of iron(III) oxide-hydroxide FeO(OH), the same chemical compound as limonite and goethite; or possibly an hydrate of the same FeO(OH)•nH $_2O.$
  
  Siderogel is described as blackish, brownish, or reddish-brown, often glassy and translucent. It may be a gossan, the result of weathering and oxidation of sulfide ores.
  
  The International Mineralogical Association does not officially recognize siderogel as a mineral species.
  
  ## Occurrence
  
  Siderogel has been reported in a few locations in Europe and Asia, including a site near Gavà and Bruguers, Catalunya; in the mine of Codos, Aragon; in the Becke-Oese quarry (now flooded) between Menden and Hemer, Germany; and in the Gaosong deposit, Gejiu China.
  
  