Tyrrellite

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Tyrrellite
Tyrrellite, Chalcomenite, Umangite-652476.jpg
Bronze colored tyrrellite with light blue chalcomenite and bluish-red-black umangite from the U-Cu-Se deposit at Eagle Claims, Beaverlodge Lake , Saskatchewan , Canada
General and classification
chemical formula
  • Cu (Co, Ni) 2 Se 4
  • (Cu, Co, Ni) 3 Se 4
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.DA.05 ( 8th edition : II / D.01)
02.10.01.04
Crystallographic Data
Crystal system cubic
Crystal class ; symbol cubic hexakisoctahedral; 4 / m  3  2 / m
Space group Fd 3 m (No. 227)Template: room group / 227
Lattice parameters a  = 10.01  Å
Formula units Z  = 8
Physical Properties
Mohs hardness ≈ 3.5 to 4.5 ( VHN 100 = 343 to 368)
Density (g / cm 3 ) measured: 6.59; calculated: 6.6 (2)
Cleavage indistinct after {001}
Break ; Tenacity clamshell; brittle
colour light bronze to brass yellow
Line color black
transparency opaque
shine Metallic luster

Tyrrellite is a very rarely occurring mineral from the mineral class of "sulfides and sulfosalts" with the chemical composition Cu (Co, Ni) 2 Se 4 , also simplified (Cu, Co, Ni) 3 Se 4 and thus chemically a copper - cobalt - Nickel - selenide and the selenium analogue of carrollite (CuCo 2 S 4 ). Structurally, both belong to the group of spinels .

Tyrrellite crystallizes in the cubic crystal system and has so far mainly been found in the form of irregular grains and poorly developed ( hypidiomorphic ) cubes up to about 0.2 mm in diameter as inclusions in umangite and berzelianite . The mineral is opaque and appears light bronze to brass yellow with a tinge of pink in the reflected light microscope . His line color , on the other hand, is black. The grain surfaces have a metallic sheen .

Etymology and history

The mineral was first discovered in the cobalt, nickel and copper selenide deposits near the Ato Bay at Beaverlodge Lake and the Eagle slot (English: Eagle Shaft ) on Mellville Lake today's region Beaver Lodge (formerly Gold Fields District) in the Canadian province Saskatchewan . It was first described in 1952 by SC Robinson and EJ Brooker, initially under the general name cobalt-nickel-copper-selenide. Subsequently, they named the mineral after the geologist and former employee of the Geological Survey of Canada Joseph Burr Tyrrell (1858-1957).

The type material of the mineral is listed in the Geological Survey of Canada in Ottawa under catalog no. 61592 and in the Royal Ontario Museum in Toronto under catalog no. M26095 and M26096 and in the Muséum national d'histoire naturelle under catalog no. 180.53 ( Cotype ) kept.

Tyrrellite was known even before the International Mineralogical Association (IMA) was founded in 1958 and was the most widely recognized mineral among experts. As a so-called grandfathered mineral (G), Tyrrellite has been recognized as an independent mineral type by the Commission on new Minerals, Nomenclature and Classification (CNMNC).

classification

The current classification of the IMA is one of the Tyrrellit to spinel supergroup , where he together with Bornhardtit and Trüstedtit forms the Bornhardtit subgroup within the Selenospinelle.

Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the tyrrellite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "sulfides with [the molar ratio] metal: S, Se, Te <1: 1 "where he together with Bornhardtit, Cadmoindit , Carrollit , daubréelite , Fletcherit , Florensovit , greigite , Indit , Kalininit , linnaeite , Polydymit , Siegenit , Trüstedtit and Violarite the" linnaeite group "with the system number. II / D.01 formed.

The 9th edition of Strunz's mineral systematics, which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), classifies the Tyrrellite in the section of "Metal sulfides with M: S = 3: 4 and 2: 3". This is further subdivided according to the exact molar ratio, so that the mineral can be found according to its composition in the sub-section "M: S = 3: 4", where it is found together with Bornhardtite, Cadmoindite, Carrollite, Cuproiridsite , Cuprorhodsite , Daubréelite, Ferrorhodsite , Fletcherit, Florensovit, greigite, Indit, Kalininit, linneite, Malanit , Polydymit, Siegenit, Trüstedtit, Violarite and Xingzhongit the "Linneitgruppe" system no. 2.DA.05 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns tyrrellite to the class of "sulfides and sulfosalts" and there into the category of "sulfide minerals". Here he is in the "Linneit group (isometric: Fd 3 m )" with the system no. 02.10.01 within the subsection " Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 3: 4 ". Template: room group / 227

Crystal structure

Tyrrellite crystallizes cubically in the space group Fd 3 m (space group no. 227) with the lattice parameter a  = 10.01  Å and 8 formula units per unit cell . Template: room group / 227

properties

Tyrrellite shows an indistinct cleavage after the {100} cube. It reacts brittle to mechanical stress and breaks like a shell like glass.

The Mohs hardness of Tyrrellite is given as ≈ 3.5 to 4.5, which roughly corresponds to that of the reference mineral fluorite (hardness 4). With the appropriate sample size, the mineral could therefore be scratched with a pocket knife.

Education and Locations

At its type locality in the Beaverlodge area, tyrrellite formed together with other selenides by hydrothermal displacement . The deposits in the find area consist mainly of umangite and some klockmannite as well as traces of berzelianite, clausthalite , pyrite , hematite and chalcopyrite . As a further displacement product was built next Tyrrellit mainly Chalkomenit . Quartz is the only gangue to be found in very small quantities.

Tyrrellite is one of the rare mineral formations that are known only in small numbers and from a few localities. So far (as of 2018) around 15 sites have been documented for Tyrrellite. Apart from its type localities Ato Bay and Eagle Shaft, the mineral has so far only been found in Canada in the Martin Lake uranium mine, which is also located in the Beaverlodge area in Saskatchewan .

In Germany, the mineral so far in the former stepped Bergbaurevier Wölsendorf in the Bavarian district Schwandorf and in a greywacke - quarry with various rare selenium minerals in Carbonatgängen at Rieder in the Harz region and the Selenerzvorkommen of the former mining area in Tilkerode ( Abberode ) in Mansfeld-Südharz in Saxony -Stop on.

Tyrrellite is still known throughout Europe from the Mina La Divina Providencia , about six kilometers east-northeast of the municipality of Villamanín (Cármenes) in the Spanish province of León , from the small calcite dike known as Hope's Nose with gold and palladium mineralization near Torquay in the English county of Devon as well as from the mining areas to Rožná (German Roschna ) and around Nove Mesto na Morave in Okres Žďár nad Sázavou Vysočina, the uranium deposit Předbořice (Černíny) in Kutná Hora District in Central Bohemia and the mountain Kokšín in the community Nové Mitrovice in Okres Plzeň-jih (German district Pilsen-Süd) in the Czech Republic.

Worldwide, with the copper-selenium deposit in the Tumiñico mine in the Argentine Sierra de Cacho ( La Rioja province ), the hydrothermal veins with selenides and sulphides in the El Dragón mine in the Bolivian province of Antonio Quijarro and the copper-cobalt-uranium Musonoi deposit near Kolwezi in the Democratic Republic of the Congo, three other sites for Tyrrellite are known.

See also

literature

  • SC Robinson, EJ Brooker: Notes and news: a cobalt-nickel-copper selenide from the Goldfields District, Saskatchewan . In: American Mineralogist . tape 37 , 1952, pp. 542–544 (English, rruff.info [PDF; 247 kB ; accessed on October 1, 2018]).
  • DC Harris: New data on tyrrellite . In: The Canadian Mineralogist . tape 10 , 1970, p. 731–736 (English, rruff.info [PDF; 667 kB ; accessed on October 1, 2018]).
  • Hexiong Yang, David K. Hubler, Barbara Lavina, Robert T. Downs and Gelu Costin: Tyrrellite, Cu (Co 0.68 Ni 0.32 ) 2 Se 4 , isostructural with spinel . In: Acta Crystallographica . C63, 2007, p. i73-i74 (English, rruff.info [PDF; 152 kB ; accessed on October 1, 2018]).

Web links

Commons : Tyrrellite  - collection of pictures, videos and audio files

Individual evidence

  1. ↑ a b c IMA / CNMNC List of Mineral Names; March 2018 (PDF 1.65 MB)
  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.  93 (English).
  3. ↑ Webmineral - Tyrrellite (English)
  4. ↑ a b c d e f g Tyrrellite . 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 October 1, 2018]).
  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. ↑ 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. 100 .
  7. ↑ Mindat - Tyrrellite (English)
  8. ↑ a b DC Harris: New data on tyrrellite . In: The Canadian Mineralogist . tape 10 , 1970, p. 731–736 (English, rruff.info [PDF; 667 kB ; accessed on October 1, 2018]).
  9. ↑ Catalog of Type Mineral Specimens - T. (PDF 87 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, p. 18 , accessed August 29, 2019 .
  10. ↑ Cristian Biagioni, Marco Pasero: The systematics of the spinel-type minerals: An overview . In: American Mineralogist . tape 99 , no. 7 , 2014, p. 1254–1264 , doi : 10.2138 / am.2014.4816 (English, preliminary version online [PDF]).
  11. ↑ Mindat - Number of localities for Tyrrellite v
  12. ↑ a b List of localities for Tyrrellite in the Mineralienatlas and Mindat