Chemistry:Cerite

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Short description: Silicate mineral group containing cerium
Cerite
Cerite.jpg
Cerite – Bastnas – Deposit Topotype
General
CategorySilicate mineral group
Formula
(repeating unit)
(Ce,La,Ca)9(Mg,Fe3+)(SiO4)6(SiO3OH)(OH)3
Crystal systemTrigonal
Crystal classDitrigonal pyramidal (3m)
(same H-M symbol)
Space groupR3c
Identification
ColorClove-brown with a reddish tinge; pale lavender-brown to colorless in thin fragments
Crystal habitMassive granular
CleavageNone
FractureUneven
Mohs scale hardness5 to 5.5
|re|er}}Vitreous to resinous
StreakWhite to greyish white
DiaphaneitySubtranslucent to opaque
Specific gravity4.7 to 4.86
Optical propertiesUniaxial (+)
Refractive indexnω = 1.806 – 1.810 nε = 1.810 – 1.820
Birefringenceδ = 0.010
References[1][2][3]

Cerite is a complex silicate mineral group containing cerium, formula (Ce,La,Ca)9(Mg,Fe3+)(SiO4)6(SiO3OH)(OH)3.[2] The cerium and lanthanum content varies with the Ce rich species (cerite-(Ce)) and the La rich species (cerite-(La)).[5][6] Analysis of a sample from the Mountain Pass carbonatite gave 35.05% Ce2O3 and 30.04% La2O3.[2]

Cerite was first described in 1803 for an occurrence in Bastnäs in Västmanland, Sweden.[3] The lanthanum rich species, cerite-(La) was first described for an occurrence in the Khibina massif, Kola Peninsula, Russia in 2002.[7]

See also

References

  1. Mineralienatlas
  2. 2.0 2.1 2.2 http://rruff.geo.arizona.edu/doclib/hom/ceritece.pdf Handbook of Mineralogy
  3. 3.0 3.1 http://webmineral.com/data/Cerite-(Ce).shtml Webmineral (Ce)
  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. http://www.mindat.org/min-931.html Mindat Cerite-(Ce)
  6. http://www.mindat.org/min-26408.html Mindat Cerite-(La)
  7. http://webmineral.com/data/Cerite-(La).shtml Webmineral (La)

External links