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Allanite

Allanite
  • Translations : Allanite
  • Synonym : Cerepidote, Cerorthite
  • Etymology : From Thomas ALLAN, Scottish mineralogist who discovered this mineral (1777-1833).
  • Discovery: 1810 by Thomas Allan (1777-1833), Scottish mineralogist
  • Type localityQáqarssuatsiaq, Aluk Island, Kap Farvel, Kujalleq, Groenland

To learn more about the mineralogy of the allanite, see Mindat.ord

Gemological data

  • Chemical formula : (Ce,Ca,Y)2 (Al,Fe+2,Fe+3)3 (SiO4)3 (OH)
  • Hardness (Mohs) : 5,5/6
  • Density : 3.5/4.2
  • Refractive index : nα = 1.715 - 1.791 nβ = 1.718 - 1.815 nγ = 1.733 - 1.822
  • Crystal system : Monoclinic
  • Group : Epidote
  • Mineralogical Class : Sorosilicates

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