Goethite

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Goethite
Goethite Angleterre.jpg
Goethite, Restormel Royal Iron Mine, Cornwall, Ingland.
General
Category Oxide minerals
Formula
(repeating unit)
α-FeO(OH)
Strunz classification 04.FD.10
Identification
Color Yellaeish tae reiddish tae dark broun
Crystal seestem Orthorhombic 2/m2/m2/m
Cleavage Perfect 010
Fractur Uneven tae splintery
Mohs scale hairdness 5 - 5.5
Luster Adamantine to dull
Streak Broun, brounish yellae tae orange yellae
Specific gravity 3.3 - 4.3
Refractive index Opaque tae sub-translucent
Fusibility Fusible at 5 - 5.5
Ither characteristics Becomes magnetic in reducin flame
References [1][2][3][4]

Goethite (FeO(OH)), (/ˈɡɜrtt/ GUR-tite) named efter the German polymath Johann Wolfgang von Goethe (1749–1832), is an airn bearin oxide mineral found in soil an ither law-temperatur environments. Goethite haes been well kent syne prehistoric times for its uise as a pigment. Evidence haes been foond of its uise in paint pigment samples taken frae the caves o Lascaux in Fraunce. It wos first describit in 1806 for occurrences in the Hollertszug Mine, Dermbach, Herdorf, Siegerland, Rhineland-Palatinate, Germany.[3]

In 2003, nanoparticulate authigenic goethite wis shawn tae be the maist common diagenetic airn oxyhydroxide in baith marine an loch sediments.[5]

References[eedit | eedit soorce]

  1. Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20th ed.). Wiley. ISBN 0-471-80580-7. 
  2. http://webmineral.com/data/Goethite.shtml Webmineral data
  3. 3.0 3.1 http://www.mindat.org/min-1719.html Mindat data with locations
  4. http://www.galleries.com/minerals/oxides/goethite/goethite.htm Mineral galleries
  5. van der Zee, C.; Roberts, D.; Rancourt, D. G.; Slomp, C. P. (2003). "Nanogoethite is the dominant reactive oxyhydroxide phase in lake and marine sediments". Geology 31 (11): 993–996. Bibcode:2003Geo....31..993V. doi:10.1130/G19924.1.