Manganoeudialyte Explained

Manganoeudialyte
Category:Cyclosilicates
Formula:Na14Ca6Mn3Zr3[Si<sub>26</sub>O<sub>72</sub>(OH)<sub>2</sub>]Cl2·4H2O
Imasymbol:Meud[1]
Class:Ditrigonal pyramidal (3m)
(same H-M symbol)
Symmetry:R3m
Unit Cell:a = 14.25, c = 30.08 [Å]
(approximated); Z = 3
Color:Pink to purple
Habit:interstitial patches
Cleavage:None
Fracture:Uneven
Tenacity:Brittle
Mohs:5–6
Luster:Vitreous
Streak:White
Diaphaneity:Transparent or translucent
Gravity:2.89–2.94 (measured)
Opticalprop:Uniaxial (+)
Refractive:nω = 1.60 nε = 1.61 (approximated)
Pleochroism:None
References:[2]

Manganoeudialyte is an moderately rare mineral of the eudialyte group,[3] with formula Na14Ca6Mn3Zr3Si2[Si<sub>24</sub>O<sub>72</sub>(OH)<sub>2</sub>]Cl2·4H2O. The formula given is one of the forms that can be given, based on the originally reported one, and shows dominance of silicon at both the M3 and M4 sites. As suggested by its name, it is the manganese-analogue of eudialyte.[4] [5]

Occurrence and association

Manganoeudialyte was discovered in khibinites of the Poços de Caldas massif, Brazil. Associated minerals are aegirine, analcime, astrophyllite, cancrinite, fluorite, lamprophyllite, nepheline, potassium feldspar, rinkite, sodalite, and titanite.

Notes on chemistry

Impurities in manganoeudialyte include strontium, potassium, niobium, aluminium, fluorine, and minor hafnium, cerium, and lanthanum.

External links

Notes and References

  1. Warr. L.N.. 2021. IMA–CNMNC approved mineral symbols. Mineralogical Magazine. 85. 3. 291–320. 10.1180/mgm.2021.43. 2021MinM...85..291W. 235729616. free.
  2. https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Manganoeudialyte Mineralienatlas
  3. Mindat, Manganoeudialyte, http://www.mindat.org/min-39640.html
  4. Nomura, S.F., Atencio, D., Chukanov, N.V., Rastsvetaeva, R.K., Coutinho, J.M.V., and Karipidis, T.K., 2010: Manganoeudialyte – a new mineral from Poços de Caldas, Minas Gerais, Brasil. Zapisko RMO 4
  5. Handbook of Mineralogy, Manganoeudialyte, http://www.handbookofmineralogy.org/pdfs/manganoeudialyte.pdf