Bogdanovite

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Bogdanovite
General and classification
other names

IMA 1978-019

chemical formula
  • (Au, Te, Pb) 3 (Cu, Fe)
  • (Cu, Fe) (Au, Te, Pb) 3
  • (Cu, Fe) Au 5 (Te, Pb) 2
  • Au 3 Cu
  • Au 5 (Cu, Fe) 3 (Te, Pb) 2
Mineral class
(and possibly department) 		Sulphides and sulphosalts (formerly elements, see classification)
System no. to Strunz
and to Dana 		2.BA.50 ( 8th edition : I / A.01)
02.02.03.01
Crystallographic Data
Crystal system cubic
Crystal class ; symbol cubic hexakisoctahedral; 4 / m  3  2 / m
Space group Pm 3 m (No. 221)Template: room group / 221
Lattice parameters a  = 4.0876  Å
Formula units Z  = 1
Physical Properties
Mohs hardness 4 to 4.5; VHN 20 = 235–270 (copper-rich), 290–354 (iron-rich)
Density (g / cm 3 ) 13.72
Cleavage no
colour pink-brown to bronze-brown, tapering to blue-black in the air
Line color not defined
transparency opaque (opaque)
shine Semi-metallic luster

Bogdanovite is a very rarely occurring mineral from the mineral class of "sulfides and sulfosalts" (formerly elements) with the chemical composition (Cu, Fe) (Au, Te, Pb) 3 or (Au, Te, Pb) 3 (Cu, Fe) The elements copper and iron as well as gold , tellurium and lead indicated in the round brackets can represent each other in the formula ( substitution , diadochy), but are always in the same proportion to the other components of the mineral. According to this formula, the mineral is one of the tellurides related to sulphides .

According to the idealized chemical composition Au 3 Cu and structure published in 1990 , Bogdanovite would, however , be grouped among the element minerals similar to the related minerals auricupride (Cu 3 Au), cuproauride (CuAu 3 ) and tetra-auricupride (CuAu).

Bogdanovite crystallizes in the cubic crystal system , but has so far only been found in the form of millimeter-sized, granular mineral aggregates . The mineral is opaque in every form and shows a semi-metal- like sheen on the surfaces . Fresh samples are pink-brown to bronze-brown in color. In the air, however, the mineral turns blue-black very quickly. On the other hand, polished surfaces show unusual color effects ranging from raspberry violet or gray violet to gold and yellow.

Etymology and history

Bogdanovite was first discovered in the Aginsk gold-silver-tellurite deposit on the Kamchatka Peninsula in the Far East Federal District of the Russian Federation. The first description was in 1979 by EM Spiridonov and TN Chvileva, who named the mineral after the Russian geologist Aleksei Alexejewitsch Bogdanow (English Aleksei Alekseevich Bogdanov ) (1907–1971).

Type material, i.e. mineral samples from its type locality , is stored in the Mining Institute in Saint Petersburg under catalog no. 115/1 and in the Fersman Museum in Moscow under catalog no. 79408 kept.

classification

In the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the Bogdanovite belonged to the mineral class of "elements (including natural alloys, intermetallic compounds, carbides, nitrides, phosphides and silicides)" and there to the department of "metals and intermetallic alloys (without semimetals) ", where together with Anyuiit , Auricuprid , Gold , Hunchunit , Copper , Novodneprit , Silver , Tetra-Auricuprid and Yuanjiangit the" Copper Series "with the system no. I / A.01 formed.

The 9th edition of Strunz's mineral systematics , valid since 2001 and used by the International Mineralogical Association (IMA), assigns Bogdanovite to the class of "sulfides and sulfosalts (including selenides, tellurides, arsenides, antimonides, bismuthides, sulfarsenides, sulfantimonides, Sulfbismutide) "and there in the section of" Metal sulfides with the molar ratio M: S> 1: 1 (mainly 2: 1) ". This is further subdivided according to the predominant metals in the compound, so that the mineral can be found according to its composition in the subdivision "with copper (Cu), silver (Ag), gold (Au)", where it is the only member of the unnamed Forms group 2.BA.50 .

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , also assigns Bogdanovite to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here he is the only member of the unnamed group 02.02.03 within the subsection “Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 3: 1”.

Chemism

The analysis of 11 microsamples - 4 of them iron-rich, 3 copper-rich and 4 intermediate - showed an empirical composition of 57.6–63.6% gold (Au), 1.67–3.39% silver (Ag), 3.32 -15.1% copper (Cu), 10.28-0.09% iron (Fe), 10.7-14.4% lead (Pb), 9.60-10.3% tellurium (Te) and 0 -0.28% selenium (Se).

Crystal structure

Bogdanovite with the idealized formula Au 3 Cu crystallizes isostructurally with isoferroplatinum (FePt 3 ) in the space group Pm 3 m (space group no. 221) with the lattice parameter a  = 4.0876  Å and one formula unit per unit cell . Template: room group / 221

Education and Locations

Bogdanovit formed in the oxidation zone of Goldtellurit - and copper deposits , where he associated with native gold and minerals Bilibinskit , Bezsmertnovit and Balyakinit and various iron, copper and lead tellurides.

Bogdanovite is one of the very rare mineral formations that has so far only been detected in a few samples that come from fewer than 10 known sites (as of 2017). In addition to its type locality Aginsk on the Kamchatka peninsula in the Far East, the mineral was only found in Russia in the Pionerskoye gold deposit in the Sayan Mountains in the autonomous republic of Tuva .

In Canada, Bogdanovit was found in the Marathon deposit near the town of the same name in the province of Ontario , which was also known for its platinum group minerals.

The rich gold deposit Manka in the Altai Mountains in Kazakhstan supplied bogdanovite and various gold tellurides in the production period from 1929 to 1955 around 6 tons of gold. In addition, Bogdanovit occurred in Kazakhstan, among others, at Dalnii Vostok in the Aqmola area and in the southern part of the Dzhelambet deposit .

In the ore body of the Campbell underground mine near Bisbee in the US state of Arizona, which mainly consists of heavily oxidized copper, bogdanovite can be found together with the type minerals henryite and kiddcreekite as well as various copper, lead and zinc minerals.

Other known, but not yet confirmed or more specifically named sites are near Salmchâteau in the Belgian municipality of Vielsalm and in the Mexican state of Sonora .

See also

literature

  • Michael Fleischer , Roger G. Burns, Louis J. Cabri, George Y. Chao, DD Hogarth and Adolf Pabst : New Mineral Names . In: American Mineralogist . tape 64 , 1979, pp. 1329–1334 ( minsocam.org [PDF; 703 kB ; accessed on December 28, 2017]).

Web links

Individual evidence

  1. ↑ a b Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: July 2019. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, July 2019, accessed August 29, 2019 .
  2. ↑ a b c Stefan Weiss: The large Lapis mineral directory. All minerals from A - Z and their properties . 6th completely revised and supplemented edition. Weise, Munich 2014, ISBN 978-3-921656-80-8 .
  3. ^ 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.  67 .
  4. ↑ a b c d Peter Bayliss: Revised unit-cell dimensions, space group, and chemical formula of some metallic minerals . In: Canadian Mineralogist . tape 28 , 1990, pp. 751-755 ( rruff.info [PDF; 436 kB ; accessed on December 28, 2017]).
  5. ↑ a b Michael Fleischer , Roger G. Burns, Louis J. Cabri, George Y. Chao, DD Hogarth and Adolf Pabst : New Mineral Names . In: American Mineralogist . tape  64 , 1979, pp. 1329–1334 ( minsocam.org [PDF; 703 kB ; accessed on December 28, 2017]).
  6. ↑ a b Bogdanovite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 ( handbookofmineralogy.org [PDF; 61  kB ; accessed on December 28, 2017]).
  7. ^ A b Richard V. Gaines, H. Catherine W. Skinner, Eugene E. Foord, Brian Mason , Abraham Rosenzweig: Dana's New Mineralogy . 8th edition. John Wiley & Sons, New York (et al.) 1997, ISBN 0-471-19310-0 , pp. 39 .
  8. ↑ 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. 44 .
  9. ↑ Catalog of Type Mineral Specimens - B. (PDF 119 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed August 29, 2019 .
  10. ↑ Find location list for Bogdanovite in the Mineralienatlas and in Mindat