Szklaryite

Szklaryite
General
Category Arsenate
Formula
(repeating unit)		 []Al6BAs33+O15
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 (approximated)
Identification
Crystal habit tiny patch
References [1][2]

Szklaryite is an extremely rare mineral with the formula []Al6BAs33+O15.[1] It is essentially vacant ("[]"), arsenic-dominant member of dumortierite supergroup, giving a name of szklaryite group. It is one of three quite recently found minerals of this group, the other two being nioboholtite and titanoholtite, all coming from the Szklary village near Ząbkowice Śląskie in Poland.[2] They occur in a unique pegmatite of probable anatectic origin.[3]

Occurrence and association

Szklaryite was detected as a tiny patch ca. 2 μm in size, in arsenic- and antimony-bearing dumortierite. Such a small size precluded determination of many of its properties. Szklaryite association is very rich and unique: nioboholtite, titanoholtite, fersmite, holtite, alluaudite, native antimony, manganese-bearing minerals of the apatite group (F-, OH- and Cl-rich apatite), native arsenic, beusite, native bismuth, cheralite, chrysoberyl, columbite-(Fe), columbite-(Mn), ernienickelite, native gold, gorceixite, hollandite, microcline, mitridatite, monazite-(Ce), muscovite, natrophilite, nontronite, various representatives of the betafite, microlite and pyrochlore groups; paradocrasite, phosphohedyphane, plumbogummite, pollucite, purpurite, quartz, ranciéite, romanèchite, saponite, spessartine, stibarsen, stibiocolumbite, stibiotantalite, tantalite-(Mn), thorutite, uraninite, xenotime-(Y), and zircon.[1]

Notes on chemistry

An important admixture in szklaryite is antimony, while titanium, iron, and aluminium occur in trace amounts.[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 "Szklaryite: Szklaryite mineral information and data". Mindat.org. Retrieved 2016-03-03.
  3. ↑ Pieczka, A., 2000. A rare mineral-bearing pegmatite from the Szklary serpentinite massif, the Fore-Sudetic Block, SW Poland. Geologia Sudetica 33, 23-31
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