Mixite

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.

Mixite
Turquoise-blue mixite, Laurium, Greece. Size: 6.8 x 5.0 x 3.6 cm.
General
Category	Arsenate mineral
Formula (repeating unit)	BiCu6(AsO4)3(OH)6·3(H2O)
IMA symbol	Mix[1]
Strunz classification	8.DL.15
Crystal system	Hexagonal
Crystal class	Dipyramidal (6/m) (same H-M symbol)
Space group	P63/m
Unit cell	a = 13.646(2) Å, c = 5.920(1) Å; Z = 2
Identification
Color	Blue to emerald-green, pale green, white
Crystal habit	Acicular crystals often in radial clusters
Fracture	Uneven
Mohs scale hardness	3–4
Luster	Vitreous
Streak	Pale green
Diaphaneity	Transparent to translucent
Specific gravity	3.79–3.83
Optical properties	Uniaxial (+)
Refractive index	nω = 1.743 – 1.749 nε = 1.810 – 1.830
Birefringence	δ = 0.067
Pleochroism	O = colorless, E = bright green
References	[2][3][4]

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

1. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
2. Mineral data publishing PDF
3. Mindat data with locations
4. 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.

• RRUFF Project

Further reading

• Downes, P. J., Hope, M., Bevan, A. W. R. and Henry, D. A. (2006): Chalcocite and associated secondary minerals from the Telfer gold mine, Western Australia. Austral. J. Mineral. 12, 25–42.
• U., Blaß, G. & Auer, C. (2010): 1618) Bleihaltiger Agardit-(La) und Brookit von der Äußeren Wimitz, St. Veit an der Glan, Gurktaler
• Alpen. P. 203 in Niedermayr et al. (2010): Neue Mineralfunde aus Österreich LIX. Carinthia II, 200./120., 199–260.
• Petr Pauliš (2000): Nejzajímavější mineralogická naleziště Čech.
• 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; Neues Jahrbuch für Mineralogie, Monatshefte (1991), 487.
• Lapis 2002(7/8), 54.
• Sejkora, J., Gabasova, A., Novotna, M. (1997): Mixite from Smrkovec near Marianské Lazné. Bulletin Mineralogicko-Petrologického Oddělení Národního Muzea (Praha), 4–5, 185–187.
• Sejkora, J.: Minerály ložiska Moldava v Krušných horách. Bulletin Mineralogicko-petrografického oddělení Národního muzea v Praze, 1994, volume. 2, s. 110–116.
• Lapis 23(4), 18–34 (1998).
• Jiří Sejkora, Petr Pauliš, Radana Malíková, Miroslav Zeman & Václav Krtek (2013): Supergenní minerály As ze štoly č. 2 Preisselberg, rudní revír Krupka (Česká republika) [Supergene As minerals from the Gallery No. 2, Preisselberg, the Krupka ore district (Czech Republic)]. Bulletin Mineralogicko-Petrologického Oddělení Národního Muzea (Praha) 21, 201–209.
• Kuttna, Kutná Hora; Sejkora, J., Ondruš, P., Fikar, M., Veselovský, F., Mach, Z., Gabašová, A., Skoda, R. & Beran, P. (2006): Supergene minerals at the Huber stock and Schnöd stock deposits, Krásno ore District, the Slavkovský les area, Czech Republic. Journal of the Czech Geological Society 51, 57–101.
• J.-L. Hohl: "Minéraux et Mines du Massif Vosgien", Editions du Rhin (Mulhouse), 1994.
• R.PIERROT, L. CHAURIS, C. LAFORET (1973) : "Inventaire minéralogique de la France : 29- Finistère.", B.R.G.M. Paris.
• Le Cahier des Micromonteurs, Bulletin de l'Association Française de Microminéralogie, 1985, N° 3, pp. 3–6.
• Le Règne Minéral 1997, 13, p. 5–18.
• Dubru. M, (1986) Pétrologie et géochimie du marbre à brucite et des borates associés au gisement de tungstène de Costabonne, (Pyrénées orientales, France) 930p.
• J.C. Escande, Z. Johan, J. Lougnon, P. Picot, F. Pillard : "Note sur la présence de minéraux de bismuth dans un filon de barytine et fluorine à Faymont, près Le Val-d'Ajol (Vosges)", Bull. Soc. Fr. Minéral. Cristallogr., 1973, 96, 398–399.
• Georges Favreau – Favreau G., Eytier J-R., Eytier C. (2010), Les minéraux de la mine de Falgayrolles (Aveyron), Le Cahier des Micromonteurs, n°109
• Inventaire Minéralogique de la France N°7, p127-128.
• [UKJMM 2:11–15 "Cap Garonne Secondary Copper and Lead – W.R. van den Berg"]
• K. Walenta: "Die Mineralien des Schwarzwaldes", Weise (Munich), 1992.
• 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.
• Wittern, A. (1995) Mineralien finden im Schwarzwald.
• Wittern: "Mineralfundorte in Deutschland", 2001.
• Schrenk, D. (2000): Die Minerale des Steinbruchs 'Blessing' bei Hornberg. Erzgräber, 14 (1), 10–17.
• Lapis, 18 (2), 13–24.
• S. Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990.
• Belendorff, K & Petitjean, K. (1987): Reichenbach im Odenwald. Die Mineralien von Fundpunkt 16.1. bei Reichenbach. LAPIS 12 (10), 23–32 + 58.
• J. Gröbner und U. Kolitsch (2006): Neufunde aus dem Erzgebirge (II). Mineralien-Welt 17 (3), 22–27.
• Frenzel, A. (1874): Mineralogisches Lexicon für das Königreich Sachsen.
• Gröbner, J. and Kolitsch, U. (2007): The minerals of the uranium prospect at Tirpersdorf, Vogtland. Lapis 32, 37–42; 58.
• Matthies, A. (2009): Mechelgrün im Sächsischen Vogtland: Uranmineralien als Haldenfunde. Lapis 34 (3), 41–43.
• T. Witzke et al.: Lapis 2001(12), 13–27.
• Jansa, J., Novák, F., Pauliš, P., Scharmová, M.: Supergenní minerály Sn-W ložiska Cínovec v Krušných horách (Česká republika). Bulletin mineralogicko-petrografického oddělení Národního muzea v Praze, 1998, roč. 6, s. 83–101.
• Sejkora, J., Škoda, R., Škácha, P., Bureš, B. & Dvořák, Z. (2009): Nové mineralogické nálezy na Sn-W ložisku Cínovec v Krušných horách (Česká republika). Bulletin mineralogicko-petrologického oddělení Národního muzea v Praze 17 (2), 23–30.
• Solomos, C., Voudouris, P. & Katerinopoulos, A. (2004): Mineralogical studies of bismuth-gold-antimony mineralization at the area of Kamariza, Lavrion. Bulletin of the Geological Society of Greece 34, Proceedings of the 10th International Congress, Thessaloniki, Greece, 387–396.
• Heymann, J. (1982): Al-Adamin. LAPIS 7 (3), 26–28.
• Lapis, 24, 7/8 (1999).
• Boscardin M., Gaetani E., Mattioli V. (1994)-Olivenite ed altre novità di Punta Corna, Valle di Viù, Piemonte-Rivista Mineralogica Italiana, Milano-Fasc. 2, pp 113–121.
• Ciriotti, M.E., Blaß, G. (2010): Pot-pourri 2009: Identificazioni UKiS AMI, Minerali italiani di interesse. Micro, 1/2010, 124–127.
• Vecchi, F., Rocchetti, I. & Gentile, P. (2013): Die Mineralien des Granits von Predazzo, Provinz Trient, Italien. Mineralien-Welt, 24(6), 98–117.
• Orlandi, P. & Criscuolo, A. (2009). Minerali del marmo delle Alpi Apuane. Pacini editore, Pisa, 180 pp.
• Panczner(1987).