Bityite

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Bityite
General
Category
2V angle
Measured: 35° to 52°
DispersionStrong
References[2][3][4]

Bityite is considered a rare

pegmatites,[7] and has only been encountered in a few localities throughout the world. The mineral was named by Lacroix[8] after Mt. Bity, Madagascar
from where it was first discovered.

Geologic occurrence

The first description of bityite was by Lacroix in 1908.

magmatic mineral.[7]

Chemical composition

The current chemical formula for bityite is CaLiAl2(AlBeSi2)O10(OH)2.[11] The mineral was analyzed by Lacroix, and concluded to be a new mineral rich with concentrations of lithium and beryllium.[8] In 1947, Rowledge and Hayton discovered a new mineral from Londonderry, Western Australia with a similar chemical composition; they named it bowleyite.[9] However, mineralogical studies performed by Strunz later confirmed that the chemical composition and properties for bowleyite were actually bityite.[7] A recent chemical analysis found in the literature was performed with heavy liquids on a sample of bityite from the Maantienvarsi dyke to derive a computed formula for bityite based on 24 oxygens; the computed chemical formula is Ca1.19K0.03Na0.02(Li1.19Al3.68Mg0.35Fe0.13)5.35(Al1.53Be2.21Si4.26)8O19.30(OH)4.54F0.16.[6]

The samples from Mt. Bity, Maantienvarsi, and Londonderry, Western Australia show similar chemical compositions as compared to the computed composition for bityite;[11] the chemical analysis for the three samples and the computed composition are tabulated in the adjacent table.

Structure

The atomic structure derived by

phyllosilicate group.[13]

Physical properties

Bityite exhibits a strong pearly

Mohs scale of hardness.[11] Bityite’s luster is vitreous and pearly on cleavages, and it has a perfect micaceous cleavage on the {001} miller index.[11] Bityite’s crystal habit can display thin and pseudohexagonal platy crystals.[11]

References

  1. S2CID 235729616
    .
  2. ^ http://rruff.geo.arizona.edu/doclib/hom/bityite.pdf Handbook of Mineralogy
  3. ^ http://webmineral.com/data/Bityite.shtml Webmineral data
  4. ^ http://www.mindat.org/min-689.html Mindat.org
  5. ^ Strunz, H. (1956) Bityit, ein berylliumglimmer. Zeitschrift für Kristallographie, 107, 325-330.
  6. ^ a b c d e f g h i j Lahti, S. I. and Saikkonen, R. (1985) Bityite 2M1 from Eräjärvi compared with related Li-Be brittle micas. Bulletin of the Geological Society of Finland, 57, 207-215.
  7. ^ a b c d e f Lin, J-C. and Guggenheim, S. (1983) The crystal structure of a Li,Be-rich brittle mica: a dioctaheral-trioctahedral intermediate. American Mineralogist, 68, 130-142.
  8. ^ a b c Lacroix, A. (1908) Les minéraux de felons de pegmatite à tourmaline lithique de Madagascar. Bulletin de la Société de Française et de Minéralogie, 31, 218-247
  9. ^ a b Rowledge, H.P. and Hayton, J.D. (1947) Two new beryllium minerals from Londonderry. Journal and Proceedings of the Royal Society of Western Australia, 33, 45-52.
  10. ^ Gallagher, M.J. and Hawkes, J.R. (1966) Beryllium minerals from Rhodesia and Uganda. Bulletin of the Geological Survey of Great Britain, 25, 59-75.
  11. ^ a b c d e f Anthony, J.W., Bideaux, R., Bladh, K., and Nichols, M. (2003) Bityite CaLiAl2(AlBeSi2)O10(OH)2 Handbook of Mineralogy, Mineral Data Publishing (Republished by the Mineralogical Society of America).*link to bityite
  12. ^ Deer, W.A, Howie, R. A., and Zussman, J. (1963) Rock-Forming Minerals, Volume 3, Sheet Silicates. Wiley, New York.
  13. ^ a b Guggenheim, S. (1984) The brittle micas. Reviews in Mineralogy, 13, 61-104.
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