Mixite Explained

Mixite
Category:Arsenate mineral
Formula:BiCu6(AsO4)3(OH)6·3(H2O)
Imasymbol:Mix[1]
Strunz:8.DL.15
System:Hexagonal
Class:Dipyramidal (6/m)
(same H-M symbol)
Symmetry:P63/m
Unit Cell:a = 13.646(2) Å,
c = 5.920(1) Å; Z = 2
Color:Blue to emerald-green, pale green, white
Habit:Acicular crystals often in radial clusters
Fracture:Uneven
Mohs:3–4
Luster:Vitreous
Streak:Pale green
Diaphaneity:Transparent to translucent
Gravity:3.79–3.83
Opticalprop:Uniaxial (+)
Refractive:nω = 1.743 – 1.749 nε = 1.810 – 1.830
Birefringence:δ = 0.067
Pleochroism:O = colorless, E = bright green
References:[2] [3] [4]

Mixite is a rare copper bismuth arsenate mineral with formula: BiCu6(AsO4)3(OH)6·3(H2O). It crystallizes in the hexagonal crystal system typically occurring as radiating acicular prisms and massive encrustations. The color varies from white to various shades of green and blue. It has a Mohs hardness of 3.5 to 4 and a specific gravity of 3.8. It has an uneven fracture and a brilliant to adamantine luster.

It occurs as a secondary mineral in the oxidized zones of copper deposits. Associated minerals include: bismutite, smaltite, native bismuth, atelestite, erythrite, malachite and barite.[2]

It was discovered in 1879 near J´achymov, Czech Republic by mine engineer Anton Mixa.[5] Mixite has also been found in Argentina,[6] Australia,[7] Austria,[8] France,[9] Germany,[10] Greece,[11] Hungary,[12] Italy,[13] Japan,[14] Mexico,[15] Namibia,[16] Poland,[17] Spain,[18] Switzerland,[19] the United Kingdom,[20] and the United States.[21]

Mixite is the namesake member of the mixite mineral group, which has the general chemical formula Cu2+6A(TO4)3(OH)6·3H2O, where A is a REE, Al, Ca, Pb, or Bi, and T is P or As. In addition to mixite, this mineral group contains the isostructural minerals agardite-(Y),[22] [23] agardite-(Ce),[24] agardite-(Nd),[25] agardite-(La),[26] calciopetersite,[27] goudeyite,[28] petersite-(Ce),[29] petersite-(Y),[23] [30] plumboagardite,[31] and zálesíite.[32]

References

Further reading

Notes and References

  1. Warr. L.N.. 2021. IMA–CNMNC approved mineral symbols. Mineralogical Magazine. 85. 3. 291–320. 10.1180/mgm.2021.43. 2021MinM...85..291W. 235729616. free.
  2. http://rruff.geo.arizona.edu/doclib/hom/mixite.pdf Mineral data publishing PDF
  3. http://www.mindat.org/min-2730.html Mindat data with locations
  4. http://webmineral.com/data/Mixite.shtml Webmineral data
  5. Schrauf A (1880) Ueber Arsenate von Joachimsthal. 1. Mixit, ein neues Kupferwismuthhydroarsenat, Zeitschrift für Krystallographie und Mineralogie (in German) 4, 277–285
  6. Lapis 8(4), 25 (1983).
  7. Kolitsch, U. and Elliott, P. (1999): Mineralogy of the Mount Malvern Mine near Clarendon, South Australia. Australian J. Mineral. 5, 3–17.
  8. G. Blass, A. Pichler: Carinthia II 191./111.: 43–55 (2001); Kolitsch,
  9. Wittern, Journée: "Mineralien finden in den Vogesen", von Loga (Cologne), 1997.
  10. Aufschluss 1986(11), 370ff.
  11. Voudouris, P. & Economou-Eliopoulus, M. (2003): Mineralogy and chemistry of Cu-rich ores from the Kamariza carbonate-hosted deposit (Lavrion), Greece. In: Eliopoulos et al. (Eds.): Mineral Exploration and Sustainable Development. Millpress, Rotterdam, 1039–1042.
  12. Geoda 2012/I.
  13. Piccoli, G.C. (2002): Minerali delle Alpi Marittime e Cozie. Provincia di Cuneo. Amici del Museo "F. Eusebio", Ed., Alba, 366 pp.; Piccoli, G. C., Maletto, G., Bosio, P., & Lombardo, B. (2007). Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo F. Eusebio – Alba, 607 pag.
  14. Matsubara et al (1992) Ganseki-Koubutsu-Koshogaku Zasshi, 87, 147–148.
  15. Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837–1892, Volume II: 944.
  16. Gebhard, G. (1999): Tsumeb II. A Unique Mineral Locality. GG Publishing, Grossenseifen, Germany
  17. Domańska, J.: Rędziny. Otoczak, nr. 29, p. 38-52.
  18. VIÑALS, J., CALVO, M., and MARTÍ, J. (2004): Parnauita, paratacamita y otros minerales secundarios de Cerro Minado, Almería. Revista de Minerales, 2, 5, 47–49.(in Spanish). Versions simultaneously published in Catalan (Mineralogistes de Catalunya) and in English version (Mineral Up)
  19. Ansermet, S. (2012): Mines et minéraux du Valais – II. Anniviers et Tourtemagne. With contributions by N. Meisser, Ed. Porte-plumes (Ayer).
  20. Golley, P., and Williams, R. (1995): Cornish Mineral Reference Manual. Endsleigh Publications (Truro), 104 pp.
  21. Grant, Raymond W., Bideaux, R.A., and Williams, S.A. (2006) Minerals Added to the Arizona List 1995–2005: 6.
  22. Dietrich J E, Orliac M, Permingeat F (1969) L’agardite, une nouvelle espèce minérale, et le problème du chlorotile, Bulletin de la Société Française de Minéralogie et de Cristallographie 92, 420–434
  23. Nickel E H, Mandarino J A (1987) Procedures involving the IMA Commission on New Minerals and Mineral Names and guidelines on mineral nomenclature, American Mineralogist 72, 1031–1042
  24. Walenta K, Theye T (2004) Agardite-(Ce) of the Clara mine in the central Black Forest, Aufschluss 55, 17–23
  25. Pekov I V, Chukanov N V, Zadov A E, Voudouris P, Magganas A, Katerinopoulos A (2011) Agardite-(Nd), NdCu6(AsO4)3(OH)6·3H2O, from the Hilarion Mine, Lavrion, Greece: mineral description and chemical relations with other members of the agardite-zálesíite solid-solution system, Journal of Geosciences 57, 249–255
  26. Fehr T, Hochleitner R (1984) Agardite-La. Ein neues mineral von Lavrion, Griechenland, Lapis 9, 22–37
  27. Sejkora J, Novotný P, Novák M, Šrein V, Berlepsch P (2005) Calciopetersite from Domašov nad Bystricí, Northern Moravia, Czech Republic, a new mineral species of the mixite group, The Canadian Mineralogist 43, 1393–1400
  28. Wise W S (1978) Parnauite and goudeyite, two new copper arsenate minerals from the Majuba Hill Mine, Pershing County, Nevada, American Mineralogist 63, 704–708
  29. Williams P A, Hatert F, Pasero M, Mills S J (2014) IMA Commission on new minerals, nomenclature and classification (CNMNC) Newsletter 20. New minerals and nomenclature modifications approved in 2014. Mineralogical Magazine 78, 549–558
  30. Peacor D R, Dunn P J (1982) Petersite, a REE and phosphate analog of mixite, American Mineralogist 67, 1039–1042
  31. Walenta K, Theye T (2005) Plumboagardite, a new mineral of the mixite group from an occurrence in the Southern Black Forest, Neues Jahrbuch für Mineralogie, Abhandlungen 181, 219–224
  32. Sejkora J, Rídkošil T, Šrein V (1999) Zálesíite, a new mineral of the mixite group, from Zálesí, Rychlebské hory Mts., Czech Republic, Neues Jahrbuch für Mineralogie, Abhandlungen 175, 105–124.