Achalaite

Achalaite ((Fe2+, Mn)(Ti, Fe3+, Ta)(Nb, Ta)2O8) is a black mineral of the wodginite group, first discovered in 2013.[2]

Achalaite
General
CategoryMineral
Formula
(repeating unit)
(Fe2+,Mn)(Ti,Fe3+,Ta)(Nb,Ta)2O8
Strunz classification4.D0.
Crystal systemMonoclinic
Unit cella = 9.422(4) [Å], b = 11.427(3) [Å]
c = 5.120(1) [Å]; β = 90.12°; Z = 4[1]
Identification
ColorBlack
Crystal habitfibrous
Mohs scale hardness5.5
Lustermetallic
Streakblack
Specific gravity6.285
Density6.285 g/cm3
PleochroismNon-pleochroic
References[1]

It crystallizes in the monoclinic system and has a dark, metallic luster, a specific gravity of 6.285 and a Mohs hardness of 5.5.[3]

Achalaite occurs in the intermediate zone of topaz- and tantalite-bearing pegmatite.[3] Associated minerals include rutile, quartz and albite.[1]

Its name comes from the type locality: the Achala batholith in Córdoba, Argentina and the mineral has been approved by the IMA with the acronym 2013-103.[1]

References

  1. "Achalaite". Mindat.org. Retrieved 8 March 2019.
  2. "The New IMA List of Minerals – A Work in Progress – Updated: July 2016" (PDF). International Mineralogical Association COMMISSION ON NEW MINERALS, NOMENCLATURE AND CLASSIFICATION. Archived from the original (PDF) on 9 September 2016. Retrieved 8 March 2019.
  3. "Achalaite Fe2+TiNb2O8" (PDF). Handbook of Mineralogy. Retrieved 8 March 2019.


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