Loparite-(Ce)

Oxide mineral
(Ce,Na,Ca)(Ti,Nb)O3IMA symbolLop-Ce[1]Strunz classification4.CC.35Crystal systemLoparit-(Ce)-Q: tetragonal[2]
Loparit-(Ce)-O: orthorhombisch[2]
Loparit-(Ce)-C: cubic[3]IdentificationColorBlack to grey-brown in thin sectionCrystal habitCubic and octahedral crystals and massiveTwinningPenetration twins common on [111]Cleavage[100] ImperfectFractureUnevenTenacityBrittleMohs scale hardness5.5–6.0LusterMetallic to sub-metallicStreakReddish brownDiaphaneityopaque, transparent in thin fragmentsSpecific gravity4.60–4.89Optical propertiesIsotropic, anomalously anisotropicRefractive indexn = 2.26–2.38References[4]

Loparite-(Ce) is a granular, brittle oxide mineral of the perovskite class. It is black to dark grey and may appear grey to white in reflected light on polished thin section with reddish brown internal reflections.[5] It has the chemical formula of (Ce,Na,Ca)(Ti,Nb)O3.[4] Nioboloparite is a variation of loparite-(Ce) containing niobium.[6]

Loparite occurs as a primary phase in nepheline syenite intrusions and pegmatites. It is also found replacing perovskite in carbonatites.[4]

Loparite was first described for an occurrence in the Khibiny and Lovozero massifs, Kola peninsula in northern Russia.

  • Crystal structures of loparite

Etymology

The term originates from the word Lopar, the (former) Russian name for the Sami indigenous inhabitants of the Kola peninsula, and the cerium content.[4][5][6]

References

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b Mitchell R H, Burns P C, Chakhmouradian A R (2000) The crystal structures of loparite-(Ce), The Canadian Mineralogist 38, 145-152.
  3. ^ Zubkova, N. V., Arakcheeva, A. V., Pushcharovskii, D. Y., Semenov, E. I., & Atencio, D. (2000). Crystal structure of loparite. Crystallography Reports, 45(2), 210-214.
  4. ^ a b c d "Loparite-(Ce)" (PDF). Mineral Handbook. Mineral Data Publishing. 2005. Retrieved 2008-07-19.
  5. ^ a b Loparite-(Ce) on Webmineral
  6. ^ a b Loparite-(Ce) on Mindat.org

External links

Wikimedia Commons has media related to Loparite-(Ce).
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  • Webmineral


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