Aurostibit

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Aurostibit
Aurostibite.jpg
Silvery-gray aurostibite crystal aggregate from Krásná Hora nad Vltavou , Czech Republic
General and classification
other names

Gold antimonide or gold diantimonide

chemical formula AusSb 2
Mineral class
(and possibly department) 		Sulfides and sulfosalts (including selenides, tellurides, arsenides, antimonides, bismuthides, sulfarsenides, sulfantimonides, sulfbismuthides)
System no. to Strunz
and to Dana 		2.EB.05a ( 8th edition : II / C.05)
02.12.01.11
Crystallographic Data
Crystal system cubic
Crystal class ; symbol cubic-disdodecahedral; 2 / m  3
Space group Pa 3 (No. 205)Template: room group / 205
Lattice parameters a  = 6.66  Å
Formula units Z  = 4
Physical Properties
Mohs hardness 3 ( VHN 100 = 280–292 kg / mm²)
Density (g / cm 3 ) measured: 9.98 (synthetic); calculated: 9.91
Cleavage indistinct
Break ; Tenacity brittle
colour lead-gray, tapering like Bornite ; on polished surfaces similar to galena white with a pink tint
Line color bronze yellow
transparency opaque (opaque)
shine Metallic luster

Aurostibit is a seldom occurring mineral from the mineral class of the "sulfides and sulfosalts" with the chemical composition AuSb 2 and thus, chemically speaking, gold antimonide (also gold diantimonide ). As close relatives of the sulfides, the antimonides are placed in the same class.

Aurostibite crystallizes in the cubic crystal system and is found in the form of elongated grains or granular aggregates of up to 3.5 cm in size as well as crusty coatings on gold in mostly lead-gray color. The surfaces of the mineral, which is opaque in every form, show a metallic sheen and can sometimes be tarnished like Bornite . Polished surfaces such as thin sections , on the other hand, reflect the light in a galena-like white with a pink tint. Its line color is bronze yellow, however.

With a Mohs hardness of 3, Aurostibite is one of the medium-hard minerals that can be scratched with a copper coin , similar to the reference mineral calcite , which is equally hard .

Etymology and history

Entrance to the Giant Mine, Canada (2005)

The compound AuSb 2 could already be synthesized in 1906 by the German materials researcher and metallograph Rudolf Vogel . In 1928 the Norwegian professor of mineralogy Ivar Oftedal (1894–1976) synthesized RuS 2 , OsS 2 and MnTe 2 in addition to AuSb 2 in order to analyze the crystal structure of these compounds of the pyrite type.

Aurostibite was first discovered as a natural mineral formation in the gold ores of the Giant Mine near Yellowknife in the Northwest Territories Province and in the Chesterville Mine near Larder Lake in the Timiskaming District of the Province of Ontario in Canada. The first description was in 1952 by Albert R. Graham and S. Cayman that the mineral based on its chemical composition according to the Latin name for gold ( Aurum ) and antimony ( stibium designated).

The type material of the mineral is listed in the collections of the Geological Survey of Canada in Ottawa under catalog no. 61458 (CT, polished section) and the Royal Ontario Museum in Toronto under catalog no. M37248 (MT, less than 1 mg, polished section) retained.

classification

Already in the outdated 8th edition of the mineral classification according to Strunz , the aurostibite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "sulfides with M: S <1: 1", where together with cattierite , geversit , hauerite , laurite , Michenerite , penroseit , pyrite , sperrylite , trogtalite , vaesite and villamanínite the "pyrite series" with the system no. II / C.05 formed.

In the Lapis mineral directory according to Stefan Weiß, which, out of consideration for private collectors and institutional collections, is still based on this old form of Karl Hugo Strunz's system , the mineral was given the system and mineral number. II / D.17-50 . In the "Lapis system" this also corresponds to the section "Sulphides with metal: S, Se, Te <1: 1", where Aurostibite together with Cattierite, Changchengite , Dzharkenite , Erlichmanite , Fukuchilit , Geversit, Hauerite, Insizwait , Kruťait , Laurit, Maslovit , Mayingit , Michenerit, Padmait , Penroseite, pyrite, Sperrylith, Trogtalit, Testibiopalladit , Vaesit and Villamanínit the "pyrite group" formed (as 2018).

The 9th edition of Strunz's mineral systematics, valid since 2001 and updated by the International Mineralogical Association (IMA) until 2009, classifies the Aurostibit in the more general section of "Metal sulfides with M: S ≤ 1: 2". However, this is further subdivided according to the exact molar ratio and the predominant metals in the compound, so that the mineral can be found in the sub-section "M: S = 1: 2, with Fe, Co, Ni, PGE etc." according to its composition where it together with cattierite, Dzharkenit, Erlichmanit, Fukuchilit, Gaotaiit , Geversit, Hauerit, Insizwait, Iridisit , Krutaite, Laurit, Penroseite, pyrite, Sperrylith, Trogtalit, Vaesit and Villamanínit the "pyrite group" with the system no. 2.EB.05a forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Aurostibit to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here it is also in the "pyrite group (isometric: Pa 3 )" with the system no. 02.12.01 to be found within the subsection “ Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 1: 2 ”. Template: room group / 205

Chemism

The chemical composition of Aurostibit (AuSb 2 ) consists of 44.72% gold (Au) and 55.28% antimony (Sb). Silver (Ag) can also be present in traces .

Crystal structure

Crystal structure of Aurostibit as a "space-filling model"

Aurostibit crystallizes cubically in the pyrite structure in the space group Pa 3 (space group no. 205) with the lattice parameter a  = 6.66  Å and four formula units per unit cell . Template: room group / 205

properties

Aurostibit can be etched with decreasing reaction strength of nitric acid (HNO 3 ), iron (III) chloride (FeCl 3 ), hydrochloric acid (HCl) and potassium hydroxide (KOH), but it reacts negatively to mercury (II) chloride (HgCl 2 ) and Potassium Cyanide Lye (KCN). Its extensive insolubility in KCN is also the reason why gold is difficult to extract from Aurostibit.

Aurostibit reacts less ductile and rather brittle to mechanical stress, but shows only an indistinct cleavage .

The mineral is normally of a rather lead-gray color and can be confused with galena due to its similarity in color . On polished surfaces, it changes its reflection behavior and appears white, similar to galena , but clearly lighter than this and with a pink tint. In oil, the decrease in brightness is less than in galena.

Education and Locations

Aurostibit formed hydrothermally on gold and antimony-containing, but low sulfur Quartz - passageways . As Begleitminerale shall be complementary to native gold and antimony various minerals such as Boulangerit , Bournonite , Chalkostibit , Freibergit , Jamesonit and stibnite (also stibnite ), you still arsenopyrite , chalcopyrite , galena , pyrite , sphalerite and tetrahedrite on.

As a rare mineral formation, Aurostibite could only be detected at a few sites, whereby around 80 sites have been documented worldwide (as of 2020). In addition to its type localities , the Giant Yellowknife Mine in the Northwest Territories and the Chesterville Mine in Ontario, the mineral occurred in several locations in various provinces in eastern Canada. It was found in the Lalor volcanic sulphide deposit near Snow Lake in Manitoba . In a river gold deposit at Clarence in York County of New Brunswick arsenopyrite , berthierite , gudmundite and pyrrhotite were added as companions and in the antimony and gold deposits of the West Gore Mine in Hants County of Nova Scotia (Nova Scotia), solid antimony was added. Aurostibit was also used in the Lapa Cadillac and Sigma No. 1 discovered near Val-d'Or in Québec and in other locations including the Thunder Bay District in Ontario.

The only known site in Germany so far is the Hornbühl with dump remains, pingen and an abandoned tunnel near Waldkirch in Baden-Württemberg.

Other locations are in Australia, Bolivia, Brazil, Bulgaria, China, the Democratic Republic of the Congo, Finland, France, Ghana, Iran, Italy, Kazakhstan, Malaysia, Norway, Russia, Sweden, Senegal, Zimbabwe, Slovakia, South Africa , in Sudan, the Czech Republic, Uzbekistan and the United States of America.

Aurostibite could also be detected in mineral samples from the Mid-Atlantic Ridge , more precisely from the hydrothermal field Semyenov-2 . World icon

See also

literature

  • Ivar Oftedal: About the crystal structures of the compounds RuS 2 , OsS 2 , MnTe 2 and AuSb 2 . With an appendix on the lattice constant of pyrite . In: Journal of Physical Chemistry . tape 135 , 1928, pp. 291–299 ( rruff.info [PDF; 376 kB ; accessed on March 4, 2020]).
  • AR Graham, S. Kaiman: Aurostibite, AuSb 2 ; a new mineral in the pyrite group . In: American Mineralogist . tape 37 , 1952, pp. 461–469 (English, rruff.info [PDF; 667 kB ; accessed on March 4, 2020]).
  • László Horváth: Mineral Species discovered in Canada and species named after Canadians (The Canadian Mineralogist Special Publication 6) . 1st edition. Mineralogical Association of Canada, Ottawa 2003, ISBN 0-921294-40-9 , pp. 24 .

Web links

Commons : Aurostibite  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b c d Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables. Chemical-structural Mineral Classification System . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p.  104 (English).
  2. ↑ Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: March 2020. (PDF 2436 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, March 2020, accessed March 4, 2020 .
  3. ^ Aurostibite. In: mindat.org. Hudson Institute of Mineralogy, accessed March 4, 2020 .
  4. ↑ a b c d Aurostibite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 (English, handbookofmineralogy.org [PDF; 64  kB ; accessed on March 4, 2020]).
  5. ↑ a b c d e Stefan Weiss: The great Lapis mineral directory. All minerals from A - Z and their properties. Status 03/2018 . 7th, completely revised and supplemented edition. Weise, Munich 2018, ISBN 978-3-921656-83-9 .
  6. ↑ a b c Paul Ramdohr : The ore minerals and their adhesions . 4th, revised and expanded edition. Akademie-Verlag, Berlin 1975, p.  882-883 .
  7. ↑ René Rausch: The periodic table of the elements online: Goldantimonid, AuSb 2 . In: periodensystem-online.de. Accessed March 31, 2020 .
  8. ^ Rudolf Vogel: Metallographische Mitteilungen from the Institute for Inorganic Chemistry of the University of Göttingen. XXXIII. About the alloys of gold with bismuth and antimony . In: Journal of Inorganic and General Chemistry . tape 50 , no. 1 , 1906, p. 145-157 , doi : 10.1002 / zaac.19060500116 .
  9. ↑ Ivar Oftedal: About the crystal structures of the compounds RuS 2 , OsS 2 , MnTe 2 and AuSb 2 . With an appendix on the lattice constant of pyrite . In: Journal of Physical Chemistry . tape 135 , 1928, pp. 291–299 ( rruff.info [PDF; 376 kB ; accessed on March 4, 2020]).
  10. ↑ Ruth Reece King, Virginia M. Jussen, John S. Pomeroy, Vsevolod L. Skitsky: Bibliography of North American Geology 1952 and 1953 . In: Geological Survey Bulletin . tape 1035 , 1956, pp. 135 (English, limited preview in Google Book Search [accessed March 4, 2020]).
  11. ↑ Catalog of Type Mineral Specimens - A. (PDF 85 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed March 4, 2020 .
  12. ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1816 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed March 4, 2020 .
  13. ^ David Barthelmy: Aurostibite Mineral Data. In: webmineral.com. Retrieved March 4, 2020 .
  14. ^ AR Graham, S. Kaiman: Aurostibite, AuSb 2 ; a new mineral in the pyrite group . In: American Mineralogist . tape 37 , 1952, pp. 461–469 (English, rruff.info [PDF; 667 kB ; accessed on March 4, 2020]).
  15. ↑ Stefan Weiß: Gold minerals and their varieties . In: gold. Mineral, power and illusion: 500 years of gold rush (= Christian Weise [Hrsg.]: ExtraLapis . Volume 2 ). Christian Weise Verlag, 1992, ISBN 3-921656-23-0 , ISSN  0945-8492 , p. 43 .
  16. ↑ Localities for Aurostibite. In: mindat.org. Hudson Institute of Mineralogy, accessed March 5, 2020 .
  17. ↑ KG Thorne, David R. Lentz, D. Hoy, LR Fyffe, Louis J. Cabri: Characteristics of Mineralization at the Main Zone of the Clarence Stream Gold Deposit, Southwestern New Brunswick, Canada: Evidence for an Intrusion-Related Gold System in the Northern Appalachian Orogenes . In: Exploration and Mining Geology . tape 17 , no. 1–2 , 2008, pp. 13–49 , doi : 10.2113 / gsemg.17.1-2.13 (English, available online at researchgate.net [accessed on March 5, 2020]).
  18. ^ Daniel J. Kontak, Richard J. Horne, Paul K. Smith: Hydrothermal characterization of the West Gore Sb-Au deposit, Meguma Terrane, Nova Scotia, Canada . In: Economic Geology . tape 91 , no. 7 , 1996, pp. 1239-1262 , doi : 10.2113 / gsecongeo.91.7.1239 (English).
  19. ^ Kurt Walenta : The minerals of the Black Forest and their places of discovery . Weise, Munich 1992, ISBN 3-921656-24-9 .
  20. ↑ Find location list for Aurostibit in the Mineralienatlas and Mindat , accessed on March 4, 2020.
  21. ↑ Anna Firstova, Tamara Stepanova, Anna Sukhanova, Georgy Cherkashov, Irina Poroshina: Au and Te Minerals in Seafloor Massive Sulphides from Semyenov-2 Hydrothermal Field, Mid-Atlantic Ridge . In: Minerals . tape 9 , no. 5 , 2019, p. 294-323 , doi : 10.3390 / min 9050294 (English).