Sorosit

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Sorosit
General and classification
other names

IMA 1994-047

chemical formula
  • Cu 1 + x (Sn, Sb)
  • Cu (Sn, Sb)
Mineral class
(and possibly department) 		Elements - metals and intermetallic compounds
System no. to Strunz
and to Dana 		1.AC.15
08/02/11/12
Crystallographic Data
Crystal system hexagonal
Crystal class ; symbol 6 / mmmTemplate: crystal class / unknown crystal class
Space group P 6 3 / mmc (No. 194)Template: room group / 194
Lattice parameters a  = 4.22  Å ; c  = 5.12 Å
Formula units Z  = 2
Physical Properties
Mohs hardness 5 ( VHN 40–50 = 381–498, average 444)
Density (g / cm 3 ) calculated: 7.6
Cleavage no
Break ; Tenacity very brittle
colour gray to almost white with a pink tinge
Line color not defined
transparency opaque (opaque)
shine Metallic luster
Crystal optics
Pleochroism medium to strong, brown-gray to blue-gray

Sorosite is a very seldom occurring mineral from the mineral class of the "elements" with the chemical composition Cu (Sn, Sb) and therefore, chemically speaking, a natural alloy of copper and tin with antimony .

Sorosit crystallizes in the hexagonal crystal system , but has so far only been found in the form of irregular to hexagonal inclusions up to 0.4 mm in size in tin . The mineral is in any form opaque ( opaque ) and displays on the surfaces of gray, the incident almost appearing white with a pink stitch crystallites a metallic luster .

Etymology and history

Name giver George Soros 2012

The mineral was first discovered in 1994 in a gold - and platinum metal - soap reservoir on the river Baimka in the west of the Chukchi Autonomous Okrug (English Chukotka ) in the Russian Far Eastern Federal District . After recognition by the International Mineralogical Association (IMA), the first description by Andrei Y. Barkov, Kauko VO Laajoki, Stanislav S. Gornostayev, Yakov A. Pakhomovskii and Yuri P. Men'shikov was published in 1998 in the specialist journal American Mineralogist .

The mineral was named after the American banker George Soros to honor his help for Russian science.

The type material of the mineral is stored in the State Mining University of Saint Petersburg in Russia under catalog no. 2083/1 kept.

classification

Since Sorosit was only recognized as an independent mineral in 1994 and this was only published in 1998, it is not yet listed in the 8th edition of the Strunz mineral classification, which has been outdated since 1977 . Only 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 , was the mineral given the system and mineral number. II / C.20-05 . In the "Lapis system" this corresponds to the class of " sulfides and sulfosalts " and there the section "sulfides with [the molar ratio ] metal: S, Se, Te ≈ 1: 1", where sorosite together with Breithauptit , Freboldite , hexastibiopanickelite , Kotulskit , Langisit , Nickelin , Sederholmit , Stumpflit , Sudburyit and Vavřínit and in the notes with Cherepanovit , polarity , Ruthenarsenit , Sobolevskit and Wassonit the "Nickelin group" (II / C.20) forms (as of 2018).

The 9th edition of Strunz's mineral systematics, which has been valid since 2001 and was last updated by the IMA in 2009, assigns Sorosit to the class of "elements" and there to the department of "metals and intermetallic compounds". This is further subdivided according to the predominant metals in the compound, which have been divided into metal families according to their related properties. Sorosit is to be found here according to its composition in the subdivision "Indium-Tin-Family", where it forms the unnamed group 1.AC.15 together with bronze (not yet recognized by the IMA, as it was published without an examination) and Yuanjiangit .

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Sorosite like the Lapis systematics to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here he is together with Achávalit , Breithauptit, Freboldit , Hexatestibiopanickelit , Kotulskit , Langisit , Nickelin, Sederholmit, Sobolevskit, Stumpflit, Sudburyit and Vavřínit in the " Nickelin group (Hexagonal: P6 3 / mmc) " with the system no. 08/02/11 within the subsection of "Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 1: 1".

Chemism

The chemical composition for sorositol was revised in 2006 by Andrei Y. Barkov, Robert F. Martin and Lang Shi and described by the formula (Cu, Fe) 1 + x (Sn, Sb) with 0.1 ≤ x ≤ 0.2. This corresponds to the idealized formula Cu 1 + x (Sn, Sb), which was adopted by the IMA.

The microprobe analysis on three samples of the type material from the Baimka deposit in Russia showed a mass fraction of 35.96 to 37.58% by weight copper (Cu), 56.43 to 57.51% by weight tin (Sn) and 4.30 to 5.23 wt% antimony (Sb). In addition, small foreign admixtures of 0.69 to 1.47% by weight iron (Fe) and 0.44 to 0.64% by weight nickel (Ni) as well as traces of cobalt (Co) up to 0.02 in one sample % By weight measured.

The proportion of antimony as a substitute for tin is significant and in the type material is up to 0.1 apfu (atoms per formula unit). However, compared with the synthetic equivalent of sorosite, up to 0.3 apfu of antimony could probably be incorporated.

Crystal structure

Sorosit crystallizes in the hexagonal crystal system with the space group P 6 3 / mmc (space group no. 194) with the lattice parameters a  = 4.22  Å and c  = 5.12 Å and two formula units per unit cell . Template: room group / 194

Education and Locations

Sorosite is formed as a secondary mineral under low-sulfur reducing conditions. As accompanying minerals , among other solid can tin and lead , Stistait , Herzenbergit and cassiterite occur.

Sorosite is one of the very rare mineral formations that have so far only been known in a few samples from less than 10 sites worldwide. Its type locality , the gold and platinum metal soap deposit on Baimka in the Chukchi Autonomous Okrug, is the only known site in Russia to date.

In Switzerland, the mineral was found in the sediments of a postglacial drainage canal near Gland VD in the Nyon district of the canton of Vaud. Locations in Germany and Austria are not yet known.

Other well-known sites are the Dunns Plains on the Arthur River on the Australian island of Tasmania , the Assarel copper mine (also Asarel) near Panagjurischte (English Panagyurishte ) in Bulgaria, the Tamaña River in the municipality of Nóvita in the Colombian department del Chocó as well the currently inactive hydrothermal hill Mir in the hydrothermal field of the Trans-Atlantic Geotraverse hydrothermal field (TAG) of the mid-Atlantic ridge .

See also

literature

  • Andrei Y. Barkov, Kauko VO Laajoki, Stanislav S. Gornostayev, Yakov A. Pakhomovskii, Yuri P. Men'shikov: Sorosite, Cu (Sn, Sb), a new mineral from the Baimka placer deposit, western Chukotka, Russian Far East . In: American Mineralogist . tape 83 , 1998, pp. 901–906 (English, rruff.info [PDF; 749 kB ; accessed on August 15, 2020]).
  • Andrei Y. Barkov, Robert F. Martin, Lang Shi: New data on type – locality sorosite: compositional variations, zoning, and a revised formula . In: The Canadian Mineralogist . tape 44 , 2006, pp. 1469–1480 (English, rruff.info [PDF; 2.5 MB ; accessed on August 17, 2020]).
  • Igor V. Pekov: New minerals from former Soviet Union countries, 1998-2006: New minerals approved by the IMA commission on new minerals and mineral names . In: Mineralogical Almanac . tape 11 , 2007, p. 45 (English, rruff.info [PDF; 3.9 MB ; accessed on February 11, 2019]).

Web links

Individual evidence

  1. ↑ a b c Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: July 2020. (PDF 2.44 MB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, July 2020, accessed August 15, 2020 .
  2. ↑ 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.  38 (English).
  3. ↑ a b c d Stefan Weiß: The large 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 .
  4. ↑ a b c d e f Sorosite . 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; 61  kB ; accessed on August 17, 2020]).
  5. ↑ a b Andrei Y.Barkov, Kauko VO Laajoki, Stanislav S. Gornostayev, Yakov A. Pakhomovskii, Yuri P. Men'shikov: Sorosite, Cu (Sn, Sb), a new mineral from the Baimka placer deposit, western Chukotka, Russian Far East . In: American Mineralogist . tape 83 , 1998, pp. 901–906 (English, rruff.info [PDF; 749 kB ; accessed on August 15, 2020]).
  6. ↑ Catalog of Type Mineral Specimens - S. (PDF; 143 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed August 15, 2020 .
  7. ↑ Ernest H. Nickel , Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF; 1.82 MB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed August 15, 2020 .
  8. ^ Andrei Y. Barkov, Robert F. Martin, Lang Shi: New data on type – locality sorosite: compositional variations, zoning, and a revised formula . In: The Canadian Mineralogist . tape 44 , 2006, pp. 1469 (English, rruff.info [PDF; 2.5 MB ; accessed on August 17, 2020]).
  9. ^ A b Andrei Y. Barkov, Robert F. Martin, Lang Shi: New data on type – locality sorosite: compositional variations, zoning, and a revised formula . In: The Canadian Mineralogist . tape 44 , 2006, pp. 1474 (English, rruff.info [PDF; 2.5 MB ; accessed on August 17, 2020]).
  10. ↑ a b List of locations for Sorosit in the Mineralienatlas and Mindat , accessed on August 15, 2020.