Černýit

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Černýit
Mineralogy and Distribution of Critical Elements in the Sn – W – Pb – Ag – Zn Huanuni Deposit, Bolivia - Figure 4b (cropped) .png
Mineral sample from Huanuni (Bolivia) in thin section with černýite, sphalerite , arsenopyrite and galena
General and classification
other names

IMA 1976-057

chemical formula
  • Cu 2 CdSnS 4
  • Cu 2 (Zn, Cd, Fe) SnS 4
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.CB.15a
02.09.02.02
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  = 5.49  Å ; c  = 10.85 Å
Formula units Z  = 2
Physical Properties
Mohs hardness ≈ 4
Density (g / cm 3 ) calculated: 4.776
Cleavage is missing
colour steel gray
Line color black
transparency opaque
shine Metallic luster

Černýite is a very rare mineral from the mineral class of sulfides and sulfosalts . It crystallizes in the tetragonal crystal system with the chemical composition Cu 2 (Zn, Cd, Fe) SnS 4 and forms up to 200 μm in size, irregularly shaped grains of steel-gray color, which form aggregates that are fused with stannite and kesterite .

Etymology and history

The mineral was first discovered in 1978 by SA Kissin, DR Owens and WL Roberts in the Tanco mine in the Canadian province of Manitoba and in the Hugo mine near Keystone in the US state of South Dakota . They named it after the Czech-Canadian mineralogist Petr Černý.

classification

Since the Černýit was only recognized as an independent mineral in 1976 and the first description was only published in 1978, it is not yet listed in the 8th edition of the mineral classification according to Strunz , which has been outdated since 1977 . Only in the Lapis mineral directory , which was revised and updated in 2018 by 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 received the system and mineral number. II / C.06-90 . 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 černýite together with barquillite , briartite , famatinite , ferrokësterite , hocartite , kesterite , Keutschit , Kuramit , Luzonit , Permingeatit , Petrukit , Pirquitasit , Rhodostannit , Sakuraiit , stannite , Toyohait and Velikit forms the "Stannit group".

The 9th edition of Strunz's mineral systematics, valid since 2001 and updated by the International Mineralogical Association (IMA) until 2009, also assigns černýite to the class of “sulfides and sulfosalts”, but there in the section of “metal sulfides, M: S = 1: 1 (and similar) ”. This is further subdivided according to the metals contained 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 Ferrokësterit, Hocartit, Idait, Kësterit, Kuramit, Pirquitasit, Stannit, 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 černýit to the class of "sulfides and sulfosalts" and there to the "sulfide minerals" category. Here, too, 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

Černýit crystallizes tetragonally in the space group I 4 2 m (space group no. 121) with the lattice parameters a  = 5.49  Å and c  = 10.85 Å as well as two formula units per unit cell . Template: room group / 121

Education and Locations

Černýit forms as a rare component in complex zoned pegmatites . As accompanying minerals may include chalcopyrite , hawleyite , pyrrhotite , sphalerite , Stannit and kesterite and dignified bismuth occur.

Černýit is one of the very rare mineral formations that have so far only been known in a few samples from less than 10 sites (as of 2019). Its type locality , the Tanco mine in the province of Manitoba, is the only documented site in Canada to date. In addition to its co-type locality, the Hugo Mine near Keystone (South Dakota) , the mineral was also found in the nearby Peerless Mine.

Other finds are known among others in Waldsassen in Bavaria ( Germany ), Hemnes in Norway , Kamienna Góra in Poland and Salamanca and Cáceres in Spain.

See also

literature

  • Kissin SA, Owens DR, Robert WL: Cernyite, a copper-cadmium-tin sulfide with the stannite structure . In: Canadian Mineralogist . tape 16 , 1978, p. 139–146 ( minsocam.org [PDF; 988 kB ; accessed on December 12, 2019]).
  • Černýite . 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 December 12, 2019]).

Web links

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

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: November 2019. (PDF 1720 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, November 2019, accessed December 12, 2019 .
  2. ↑ David Barthelmy: Cernyite MineralData. In: webmineral.com. Retrieved December 12, 2019 .
  3. ^ A b c 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).
  4. ↑ a b Černýite . 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]).
  5. ↑ 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 .
  6. ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1816 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed December 12, 2019 .
  7. ↑ Find location list for Černýit at the Mineralienatlas and at Mindat , accessed on December 12, 2019.