Gustavite

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Gustavite
Gustavit, Rotgülden (Lungau) .jpg
Gustavite on pyrite. Mining region Rotgülden in Lungau / Tamsweg district , State of Salzburg , Austria (image height 1.5 cm)
General and classification
chemical formula PbAgBi 3 S 6
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.JB.40
04.03.15.03
Crystallographic Data
Crystal system monoclinic
Crystal class ; symbol monoclinic prismatic; 2 / m
Space group P 2 1 / c (No. 14)Template: room group / 14
Lattice parameters a  = 7.077  Å ; b  = 19.566 Å; c  = 8.272 Å
α  = 90 °; β  = 107.18 °; γ  = 90 °
Formula units Z  = 4
Twinning available
Physical Properties
Mohs hardness 3.5
Density (g / cm 3 ) calculated: 7.01
Cleavage imperfect
colour white to off-white
Line color Gray
transparency opaque (opaque)
shine Metallic luster
Crystal optics
Pleochroism recognizable from white to gray
Other properties
Special features Possible contamination by Sb

Gustavite is a rather seldom occurring mineral from the mineral class of " sulfides and sulfosalts " with the chemical composition PbAgBi 3 S 6 and thus chemically a lead - silver - bismuth sulfide.

Gustavite crystallizes in the monoclinic crystal system and is often found in the form of needle-like or long-columned crystals a few millimeters in length. Furthermore, the mineral appears coarse and associated with other ore minerals such as pyrite or arsenopyrite as inclusions of up to a few centimeters in size. From its type locality, the cryolite -Lagerstätte Ivigtut in Greenland and from Colorado tabular, gray and white twinned crystals to be described to two millimeters in size. Gustavit in any form opaque ( opaque ) and displays on the surface of white to off-white crystals or grains of a metallic luster .

Etymology and history

Gustavit was first described by S. Karup-Møller in 1970 and named in honor of Gustav Adolf Hageman. Hageman was a chemical engineer for the cryolite mining company in Ivigtut in the Sermersooq commune in Greenland . The local cryolite deposit on the Arsuk Fjord also represents the type of locality of the mineral.

The Gustavit type material is sold at the University of Copenhagen in Denmark under catalog no. 1973.188 and in the collection of the National Museum of Natural History in Washington, DC in the United States under catalog no. 136172 kept.

classification

Since the 9th edition of Strunz's mineral systematics, the mineral has been part of the “Sulphosalts with PbS as a model” section and there to the “Galena derivatives with lead (Pb)” subdivision. It forms there together with Andorit IV , Andorit VI , Fizélyit , Lillianit , Ramdohrit , Roshchinit , Treasurit , Uchucchacuait , Vikingit and Xilingolit the Lillianitgruppe .

The systematics of minerals according to Dana also assigns gustavite to the class of sulphides and there, together with andorite , bursaite , fizélyite , lillianite , ramdohrite , roshchinite and uchucchacuaite also in the " lillianite group (Orthorhombic, with the composition A m B n S 6 with A = Pb, Ag, Mn and B = Sb, Bi) "within the section of" sulfosalts with the ratio 3> z / y and the composition (A + ) i  (A 2+ ) j  [B y C z ], A = metals, B = semi-metals, C = non-metals ”.

Crystal structure

Gustavite crystallizes in the monoclinic crystal system in the space group P 2 1 / c (space group no. 14) with the lattice parameters a  = 7.077,  b  = 19.566 and  c  = 8.272  Å as well as four formula units per unit cell . Template: room group / 14

Education and Locations

Gustavite is formed by hydrothermal processes , especially in pegmatite deposits. Accompanying minerals include barite , chalcopyrite , pyrrhotite , tetrahedron , pyrite and Eskimoite .

As a rather rare mineral formation, gustavite is not very common. So far (as of 2020) around 125 sites are known to be known. In addition to its type locality, the cryolite deposit on the Arsuk Fjord near Ivigtut , Kommuneqarfik Sermersooq in Greenland , the mineral was also found in North America in a total of five Canadian silver, copper, molybdenum and tantalum deposits, including the Silver Bear Mine on Great Bear Lake in the Northwest Territories . For the western USA, a total of 13 other sites from ore deposits in Colorado , California , Nevada , Idaho and Montana are known. Gustavite has so far been found in six locations in South America: two each in Bolivia , Peru and Argentina .

In Europe, Gustavit was described in a total of 66 locations from Bulgaria, Finland, France, Greece, Italy, Poland, Romania, Scotland, Sweden, Slovakia, Spain, the Czech Republic and the Ukraine.

In Germany, the mineral was found in the Brüderbund iron ore mine in the Kohlenbachtal in Siegen- Eiserfeld in the North Rhine-Westphalian district of Siegen-Wittgenstein , in the Monzo granite quarry Jenichen in the municipality of Königshain in the Saxon district of Görlitz and in five former mines in the Black Forest , including the Clara mine in Oberwolfach ( Ortenaukreis ) and the Gottesehre mine in the community of Dachsberg near Urberg in the southern Black Forest ( Waldshut district ).

The 17 locations of Gustavite described for Austria extend over the federal states of Carinthia , Salzburg , Styria and Tyrol . These include the Mittersill Scheelite deposit and the Hochfeld copper mine in Neukirchen am Großvenediger in the Zell am See district and the Rotgülden mining region near Muhr in Lungau / Tamsweg district in the State of Salzburg.

Another 34 sites are known from Asia. They are located in China , Japan , Russia , South Korea , Tajikistan and Uzbekistan .

use

Due to its rarity, gustavite is of no importance as either silver or bismuth ore. Levels of the mineral are only sought after by collectors.

See also

literature

  • Karup-Møller, S. (1970): Gustavite, a new sulphosalt mineral from Greenland. In: The Canadian Mineralogist 10, 173-190.
  • Fleischer, M. (1971): New mineral names. In: American Mineralogist 56, 631-640.
  • Harris, D.C. & Chen, T.T. (1975): Gustavite: two Canadian occurrences. In: The Canadian Mineralogist : 13, 411-414.
  • Makovicky, E. & Karup-Møller, S. (1977): Chemistry and crystallography of the lillianite homologous series. II. Definition of new minerals eskimoite, vikingite, ourayite and treasurite. Redefinition of schirmerite and new data on the lillianite-gustavite solid-solution series. In: New Yearbook for Mineralogy , Abhandlungen 131, 56–82.
  • Karup-Møller, S. & Makovicky, E. (1979): On pavonite, cupropavonite, benjaminite, and "oversubstituted" gustavite. In: Bulletin de Minéralogie 102, 351-367.
  • Moëlo, Y., Marcoux, E., Makovicky, E., Karup-Møller, S. & Legendre, O. (1987): Homologues de la lillianite (gustavite, vikingite, heyrovskyite riche en Ag et Bi ...) de l'indice à W-As- (Pb, Bi, Ag) de La Roche-Balue (Loire Atlantique, France). In: Bulletin de Minéralogie 110, 43-64.
  • Chang, L. L. Y., Wu, D. & Knowles, C. R. (1988): Phase relations in the system Ag 2 S-Cu 2 S-PbS-Bi 2 S 3 . In: Economic Geology 83, 405-418.
  • Bente, K., Engel, M. & Steins, M. (1993): Crystal structure of lead silver tribismuth sulfide, PbAgBi 3 S 6 . In: Z. Kristallogr 205, 327–328 (Synthetic orthorhombic gustavite with static distribution of silver and bismuth. Natural gustavite shows Ag-Bi disorder).
  • Pažout, R., Ondruš, P. & Šrein, V. (2001): Gustavite with variable Bi / Sb ratio from Kutná Hora deposit, Czech Republic, a new occurrence. In: New Yearbook for Mineralogy , monthly books 2001, 157–168.
  • Sureda, R., Lira, R. & Colombo, F. (2006): Gustavite, PbAgBi 3 S 6 [P21 / c], with the bismuth and silver minerals at Los Guindos mining group, Pampa de Olaen, Cordoba, Argentina ( 3111'S / 6433'W). In: Revista Geologica de Chile 33, 141-160.
  • Pažout, R. & Dušek, M. (2009): Natural monoclinic AgPb (Bi 2 Sb) 3 S 6 , an Sb-rich gustavite. In: Acta Crystallographica 65, 77-80.
  • Pažout, R. & Dušek, M. (2010): Crystal structure of natural orthorhombic Ag 0.71 Pb 1.52 Bi 1.32 Sb 1.45 S 6 , a lillianite homologue with N = 4; comparison with gustavite. In: European Journal of Mineralogy 22, 741-750.
  • Makovicky, E. & Topa, D. (2011): The crystal structure of gustavite, PbAgBi 3 S 6 . Analysis of twinning and polytypism using the OD approach. In: European Journal of Mineralogy: 23, 537-550.
  • Yang, H., Downs, R. T., Evans, S. H. & Pinch, W. W. (2013): Terrywallaceite, AgPb (Sb, Bi) 3 S 6 , isotypic with gustavite, a new mineral from Mina Herminia, Julcani Mining District, Huancavelica, Peru . In: American Mineralogist 98, 1310-1314.
  • Pažout, R. (2017): Lillianite homologues from Kutná Hora ore district, Czech Republic: a case of large-scale Sb for Bi substitution. In: Journal of Geosciences 62, 37-57 (on Sb-rich gustavite).

Web links

Individual evidence

  1. ↑ a b Rösler, Hans Jürgen : Textbook of Mineralogy . 3. Edition. VEB German publishing house for basic industry , Leipzig 1984, p.  352 .
  2. ↑ a b c d e f g h i Gustavite. In: mindat.org . Hudson Institute of Mineralogy, accessed April 18, 2020 .