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

Goethite
Goethite, Restormel Royal Iron Mine, Cornwall, Ingland.
General
CategoryOxide meenerals
Formula
(repeatin unit)
α-FeO(OH)
Strunz clessification04.FD.10
Creestal seestemOrthorhombic 2/m2/m2/m
Identification
ColourYellaeish tae reiddish tae dark broun
CleavagePerfect 010
FracturUneven tae splintery
Mohs scale haurdness5 - 5.5
SkinkleAdamantine to dull
StreakBroun, brounish yellae tae orange yellae
Speceefic gravity3.3 - 4.3
Refractive indexOpaque tae sub-translucent
FusibilityFusible at 5 - 5.5
Ither chairacteristicsBecomes magnetic in reducin flame
References[1][2][3][4]

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

References

eedit
  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. a b http://www.mindat.org/min-1719.html Mindat data with locations
  4. http://www.galleries.com/minerals/oxides/goethite/goethite.htm Archived 2011-10-16 at the Wayback Machine 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.