Cerianite-(Ce)

Cerianite-(Ce)
General
Category Oxide
Formula
(repeating unit)
(Ce,Th)O2
Crystal system Isometric - Hexoctahedral (point group m3m)
Space group Isometric
Space group Fm3m
Unit cell a=5.42 [Å]
Identification
Color Dark greenish amber-yellow, yellow, buff
Crystal habit octahedra; earthy, massive
Diaphaneity Translucent or transparent
Density 7.20 (synth. material, calc.; approximated)
References [1][2]

Cerianite-(Ce) is a relatively rare oxide mineral, belonging to uraninite group with the formula (Ce,Th)O2.[3][2] It is one of a few currently known minerals containing essential tetravalent cerium, the other examples being stetindite and dyrnaesite-(La).[4][5]

Occurrence and association

Cerianite-(Ce) is associated with alkaline rocks, mostly nepheline syenites.[1] It may be found in carbonatites.[2] Cerianite-(Ce) associates with minerals of the apatite group, bastnäsite-group minerals, calcite, feldspar, "fluocerite", "hydromica", ilmenite, nepheline, magnetite, "törnebohmite" and tremolite.[1] It is the most simple cerium mineral known.[2]

Notes on chemistry

Beside thorium cerianite-(Ce) may contain trace niobium, yttrium, lanthanum, ytterbium, zirconium and tantalum.[1]

Crystal structure

For details on crystal structure see cerium(IV) oxide.

References

  1. 1 2 3 4 "Cerianite-(Ce) - Handbook of Mineralogy" (PDF). Handbookofmineralogy.org. Retrieved 2016-03-04.
  2. 1 2 3 4 "Cerianite-(Ce): Cerianite-(Ce) mineral information and data". Mindat.org. Retrieved 2016-03-04.
  3. Graham, A.R., 1955. Cerianite CeO2: a new rare-earth oxide mineral. American Mineralogist 40, 560-564
  4. "Stetindite: Stetindite mineral information and data". Mindat.org. Retrieved 2016-03-04.
  5. "Dyrnaesite-(La): Dyrnaesite-(La) mineral information and data". Mindat.org. Retrieved 2016-03-04.
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