Misplaced Pages

Hollandite

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
Barium manganese oxide mineral
Hollandite
General
CategoryOxide minerals
Formula
(repeating unit)		Ba(Mn6Mn2)O16
IMA symbolHol
Strunz classification4.DK.05a
Dana classification7.9.1.1
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
Space groupMonoclinic
H-M symbol: (2/m)
Space group: I2/m
Identification
ColorSilvery-grey to greyish
CleavageDistinct / Good, Prismatic
Mohs scale hardness4 to 6
Density4.95

Hollandite (chemical formula: Ba(Mn6Mn2)O16) is a manganese oxide mineral. Its structure consists of double chains of MnO6 octahedra delimiting 2 × 2 tunnels. The electrostatic charge created by the Mn for Mn substitution is balanced by cations in the tunnels. Their nature determines the mineral species: Ba for hollandite, K for cryptomelane, Pb for coronadite, Sr for strontiomelane, Tl for thalliomelane, and Na for manjiroite. Pure species are rare and most 2 × 2 tectomanganates contain mixtures of several types of tunnel cations.

A mineral, with the chemical composition BaMn6Fe2O16, that was first found in the Kajlidongri mine in the Jhabua district of Madhya Pradesh, India, had the name hollandite until it was reclassified as ferrihollandite by the International Mineralogical Association in 2012. Ferrihollandite is the barium-iron (III) endmember of the coronadite group.

  • Hollandite star in rare quartz inclusion Hollandite star in rare quartz inclusion
  • Polyhedral representation of the 2 x 2 tunnel structure of hollandite. The black atoms represent Ba. Polyhedral representation of the 2 x 2 tunnel structure of hollandite. The black atoms represent Ba.

See also

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. ^ "Hollandite". Mindat.org. Retrieved 15 February 2022.
  3. Mindat.org
  4. Mindat.org
  5. Mindat.org
  6. "Archived copy". Archived from the original on 2017-04-02. Retrieved 2017-04-01.{{cite web}}: CS1 maint: archived copy as title (link)
  7. "Hollandite" (PDF). Rruff.info. p. 252. Retrieved 15 February 2022.
  8. Post JE, Von Dreele RB, Buseck P (1982) Acta Crystallographica B38: 1056-1065
Categories: