Chemistry:Feroxyhyte

From HandWiki
Short description: Iron hydroxide mineral
Feroxyhyte
General
CategoryOxide mineral
Formula
(repeating unit)
δ-Fe3+O(OH)
Strunz classification4.FE.40
Dana classification06.01.04.04
Crystal systemHexagonal
Unknown space group
Unit cella = 2.95, c = 4.56 [Å]; Z = 1
Identification
Formula mass88.85 g/mol
ColorBrown, yellow-brown
Crystal habitConcretionary, massive, nodular
StreakYellow
DiaphaneityOpaque
Specific gravity4.31
Density4.2
Optical propertiesUniaxial
References[1][2][3]

Feroxyhyte is an oxide/hydroxide of iron, δ-Fe3+O(OH). Feroxyhyte crystallizes in the hexagonal system. It forms as brown rounded to concretionary masses. Feroxyhyte is opaque, magnetic, has a yellow streak, and has a relative density of 4.2.[2]

It occurs in manganese-iron nodules on the Atlantic and Pacific Ocean floors. It is also found in the Baltic, White, and Kara Seas.[5] Forms under high pressure conditions and reverts to goethite on exposure to surface conditions.[2] It also occurs as cement and coatings on clasts in poorly drained soils and sediments, formed by the rapid oxidation of iron(II) oxide compounds.[5]

It was first described in 1976 for an occurrence in soils at its type locality: Kolomyya, Ivano-Frankivsk Oblast, Ukraine .[1][5]

References

  1. 1.0 1.1 "Feorxyhyte mineral information and data". Mindat.org. http://www.mindat.org/min-1484.html. Retrieved 2011-10-24. 
  2. 2.0 2.1 2.2 "Feroxyhyte Mineral Data". Webmineral.com. http://webmineral.com/data/Feroxyhyte.shtml. Retrieved 2011-10-24. 
  3. "Information card - FEROXYHYTE". Mineral Crystal Structure Database. http://database.iem.ac.ru/mincryst/s_carta.php?FEROXYHYTE. Retrieved 2011-10-24. 
  4. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode2021MinM...85..291W. 
  5. 5.0 5.1 5.2 Handbook of Mineralogy