Kuramit

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Kuramit
General and classification
other names

IMA 1979-013

chemical formula Cu 3 SnS 4
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.CB.15a ( 8th edition : II / C.06)
02.09.02.04
Crystallographic Data
Crystal system tetragonal
Crystal class ; symbol tetragonal-scalenohedral; 4 2 m
Space group I 4 2 m (No. 121)Template: room group / 121
Lattice parameters a  = 5.45  Å ; c  = 10.75 Å
Formula units Z  = 2
Physical Properties
Mohs hardness 4.5 ( VHN 100 = 322–373, average 353)
Density (g / cm 3 ) measured: not defined; calculated: 4.56
Cleavage not defined
colour Gray
Line color Please complete!
transparency opaque (opaque)
shine Metallic luster

Kuramite is a very seldom occurring mineral from the mineral class of "sulfides and sulfosalts" with the chemical composition Cu 3 SnS 4 and thus chemically a copper - tin - sulfide .

Kuramite crystallizes in the tetragonal crystal system and forms inclusions up to 80 μm in goldfieldite in the form of round to elongated grains. The mineral is opaque and appears neutral gray in polished sections with a metallic sheen on the surfaces.

Etymology and history

The mineral was first found in 1979 by VA Kovalenker, TL Evstigneeva, NV Traneva and LN Vyalsov in a gold deposit in the Chatkal and Qurama Mountains in eastern Uzbekistan . It is named after the place where it was found.

classification

Since Kuramit was only recognized as an independent mineral type by the International Mineralogical Association (IMA) in 1979 , it is not yet listed in the 8th edition of the Strunz mineral classification, which has been outdated since 1977 .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 , which was revised and updated in 2018 by Stefan Weiß, which is still based on this classic system from Karl Hugo Strunz out of consideration for private collectors and institutional collections , the mineral received the system and mineral number. II / C.06-50 . In the "lapis system" this corresponds to the class of "sulfides and sulfosalts" and there the section "sulfides with metal: S, Se, Te ≈ 1: 1", where kuramite together with barquillite , briartite , černýite , famatinite , ferrokësterite , Hocartit , kesterite , Keutschit , Luzonit , Permingeatit , Petrukit , Pirquitasit , Rhodostannit , Sakuraiit , stannite , Toyohait and Velikit forms the "Stannit group".

The 9th edition of Strunz's mineral systematics, which has been in force since 2001 and updated by the International Mineralogical Association (IMA) until 2009, also classifies the kuramite in the category of “metal sulfides, M: S = 1: 1 (and similar)”. However, this is further subdivided according to the predominant metals in the compound, so that the mineral can be found in the sub-section "with zinc (Zn), iron (Fe), copper (Cu), silver (Ag) etc." according to its composition , where together with Černýit, Ferrokësterit, Hocartit, Idait , Kësterit, Pirquitasit, Stannit and Velikit the "stannite group" with the system no. 2.CB.15a forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Kuramite to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here it is in the " stannite group (tetragonal: I 4 2 m ) A 2 BCS type" with the system no. 02.09.02 within the subsection "Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 1: 1". Template: room group / 121

Crystal structure

Kuramit crystallizes tetragonally in the space group I 4 2 m (space group no. 121) with the lattice parameters a = 5.45  Å and c = 10.75 Å, as well as two formula units per unit cell . Template: room group / 121

Education and Locations

Kuramite forms in gold-sulphide-quartz veins. It is associated with goldfieldite, famatinite , hessite , petzite , sylvanite , altaite , gold , chalcostibite , emplectite , mohite , mawsonite and cassiterite .

In addition to the type locality in Uzbekistan, there are other sites from Andalgalá and Salta in Argentina , Katanga in the Democratic Republic of the Congo , Recsk in Hungary , St Austell in England as well as Bisbee , the Red Mountains and several locations in Nevada in the United States .

See also

literature

  • VA Kovalenker, TL Evstigneeva, NV Troneva and LN Vyal'sov: Kuramite, Cu 3 SnS 4 , new mineral of the stannite group . In: Zapiski Vsesoyuznogo Mineralogicheskogo Obshchestva . tape 108 , 1979, pp. 564-569 , doi : 10.1080 / 00206818109455070 (English, []). :
  • Michael Fleischer , Louis J. Cabri, George Y. Chao, Adolf Pabst : New Mineral names . In: American Mineralogist . tape 65 , 1980, pp. 1065-1070 (English, minsocam.org [PDF; 721 kB ; accessed on July 15, 2019]).

Web links

Individual evidence

  1. ↑ Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: May 2019. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, March 2019, accessed May 20, 2019 .
  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.  78 (English).
  3. ↑ a b 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 Kuramite . 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; 63  kB ; accessed on July 15, 2019]).
  5. ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed July 15, 2019 .
  6. ↑ Find location list for at [Mineralienatlas https://www.mineralienatlas.de/lexikon/index.php/MineralDataShow?mineralid=2086§ions=12 ] and at Mindat