Titanoholtite

Titanoholtite
General
Category Silicate mineral
Formula
(repeating unit)		 (Ti0.75[]0.25)Al6BSi3O18
Crystal system Orthorhombic
Crystal class Dipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space group Pbcm
Unit cell a = 47.00 Å, b = 11.83 Å
c = 20.24 Å
Identification
References [1][2]

Titanoholtite is an extremely rare mineral with the formula (Ti0.75[]0.25)Al6BSi3O18. It is titanium-rich member of dumortierite supergroup, and titanium-analogue of holtite of the holtite group. It is one of three quite recently found minerals of this group, the other two being nioboholtite and szklaryite, all coming from the Szklary village near Ząbkowice Śląskie in Poland. They occur in a unique pegmatite of probable anatectic origin.[1][2]

Association

Titanoholtite is closely associated with holtite and nioboholtite; its further association is very rich (see szklaryite).[1]

Notes on chemistry

Impurities in titanoholtite are mainly antimony and arsenic, with trace niobium, tantalum, titanium, and iron.[1]

References

  1. 1 2 3 4 Pieczka, A.; Evans, R. J.; Grew, E. S.; Groat, L. A.; Ma, C.; Rossman, G. R. (2013). "The dumortierite supergroup. II. Three new minerals from the Szklary pegmatite, SW Poland: Nioboholtite, (Nb0.6〈0.4)Al6BSi3O18, titanoholtite, (Ti0.75〈0.25)Al6BSi3O18, and szklaryite, 〈Al6BAs3+3O15". Mineralogical Magazine. 77 (6): 2841. doi:10.1180/minmag.2013.077.6.10.
  2. 1 2 "Titanoholtite: Titanoholtite mineral information and data". Mindat.org. Retrieved 2016-03-03.


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