Daubréelith

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Daubréelith
General and classification
other names

Daubreelith

chemical formula FeCr 2 S 4
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.DA.05 ( 8th edition : II / C.01)
02.10.01.11
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  = 9.97  Å
Formula units Z  = 8
Physical Properties
Mohs hardness 5 (VHN 100 = 260–303)
Density (g / cm 3 ) 3.81
Cleavage clear
Break ; Tenacity uneven; very brittle
colour black
Line color brown to black
transparency opaque (opaque)
shine Metallic luster

Daubréelith is a rarely occurring mineral from the mineral class of "sulfides and sulfosalts". It crystallizes in the cubic crystal system with the chemical composition FeCr 2 S 4 and is therefore chemically an iron - chromium - sulfide . Structurally, however, Daubréelith belongs to the group of spinels .

Daubréelith is mainly found in the form of massive or flaky to platy mineral aggregates , but also as individual crystallites ( grains ) of around 500 µm in size, alongside kamacite and troilite, in meteorites . The crystallites and aggregates are opaque and black in color with a metallic sheen .

Etymology and history

Name giver Gabriel Auguste Daubrée

The mineral was first discovered in the nickel-iron meteorite ( hexaedrite ) Coahuila , which was discovered in 1837 in the state of the same name in Mexico . The mineral was first described in 1876 by JL Smith in the American Journal of Science , who named it after the French meteorite researcher Gabriel Auguste Daubrée (1814-1896).

The type material of the mineral is in the Muséum national d'histoire naturelle (Sigel MNHN or English MHN) in Paris, France under the catalog no. 76.196 , 96.1113 and 94.248 .

classification

The current classification of the IMA counts the Daubréelith to the “ spinel supergroup ”, where together with cadmoindite , cuprorhodsite , greigite , indite , joegoldsteinite , kalininite , linneit , polydymite , siegenite , violarite and xingzhongite it forms the “linneit subgroup” within the “thiospinelle” "Forms (as of 2019).

In the outdated 8th edition of the mineral classification according to Strunz , the Daubréelite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "sulfides with the molar ratio of metal: sulfur, selenium, tellurium <1: 1", where together with Bornhardtite , Carrollit , Greigit, Indit, Linneit, Polydymit, Siegenit, Trüstedtit , Tyrrellite and Violarit as well as in the attachment Wilkmanit the "Linneit series" with the system no. II / C.01 formed.

In the last revised and updated Lapis mineral directory by Stefan Weiß in 2018 , which, out of consideration for private collectors and institutional collections, is still based on this classic system of Karl Hugo Strunz , the mineral was given the system and mineral number. II / D.01 . In the "Lapis system" this also corresponds to the section "Sulphides with metal: S, Se, Te <1: 1", where Daubréelite together with Bornhardtite, Cadmoindite, Carrollite, Cuprokalininite , Fletcherite , Florensovite , Greigite, Indite, Kalininite, Linneit, Polydymit, Siegenit, Trüstedtit, Tyrrellite and Violarit form the "Linneit Group" with the system no. II / D forms.

The 9th edition of Strunz's mineral systematics, which has been in effect since 2001 and was updated by the International Mineralogical Association (IMA) until 2009, classifies the Daubréelith in the category 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, Ferrorhodsite , Fletcherite, Florensovit, greigite, Indit, Kalininit, linnaeite, Malanit , Polydymit, Siegenit, Trüstedtit, Tyrrellit, Violarite and Xingzhongit the "Linneitgruppe" with the system number. 2.DA.05 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Daubréelith to the class of "sulphides and sulphosalts" and there in the category of "sulphide minerals". Here he is also a member of 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

Daubréelith crystallizes cubically in the space group Fd 3 m (space group no. 227) with the lattice parameter a  = 9.97  Å and 8 formula units per unit cell . Template: room group / 227

Education and Locations

Daubréelith forms in small quantities mainly in nickel - iron meteorites , mostly together with the likewise meteoritic minerals kamacite and troilite . Other accompanying minerals can be alabandin , enstatite , graphite , various plagioclase and writersite .

As a rare mineral formation, Daubréelith could only be detected at a few sites, with around 150 sites being documented to date (as of 2019).

With a few exceptions, the mineral has so far only been found in meteorites such as ALH 84001 in the Antarctic, Mundrabilla meteorite in Australia, Neuschwanstein (meteorite) in Germany, Bustee meteorite near Gorakhpur in India, Allende (meteorite) in Coahuila (Mexico ), Gibeon meteorite and meteorite Hoba in Namibia, Mayo-Belwa in the Nigerian state of Adamawa , Muonionalusta meteorite in the Swedish municipality of Pajala and in the Canyon-Diablo meteorites and impact craters of Newporte in North Dakota and Norton County in the USA .

The “Karee Mine” near Rustenburg in the northwest province of South Africa and the Kosva massif near Karpinsk in the Russian Oblast of Sverdlovsk are very rare, purely terrestrial sites .

On the moon , it could be detected in meteoritic rock samples from the Hadley groove in the Mare Imbrium , near which the Apollo 15 mission landed.

See also

literature

  • JL Smith: Aragonite on the surface of a meteoric iron, and a new mineral (Daubréelite) in the concretions of the interior of the same . In: American Journal of Science and Arts . tape 112 , 1876, pp. 107-110 (English).

Web links

Individual evidence

  1. ↑ a b c d e 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).
  2. ↑ a b c Daubréelite . 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 June 23, 2019]).
  3. ^ Friedrich Klockmann : Klockmanns textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp.  450 (first edition: 1891).
  4. ↑ Coahuila. In: www.lpi.usra.edu. Meteoritical Bulletin Database, accessed June 23, 2019 .
  5. ↑ Catalog of Type Mineral Specimens - D. (PDF 50 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed June 23, 2019 .
  6. ↑ Ferdinando Bosi, Cristian Biagioni, Marco Pasero: Nomenclature and classification of the spinel supergroup . In: European Journal of Mineralogy . tape 31 , no. 1 , September 12, 2018, p. 183–192 , doi : 10.1127 / ejm / 2019 / 0031-2788 (English).
  7. ↑ 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 .
  8. ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed April 25, 2019 .
  9. ↑ Localities for Daubréelite. In: mindat.org. Hudson Institute of Mineralogy, accessed June 23, 2019 .
  10. ↑ Find location list for Daubréelith at the Mineralienatlas and at Mindat
  11. ↑ Karee Mine, Rustenburg (Rustenburg District), Western Bushveld Complex, Bojanala Platinum District, North West, South Africa. In: mindat.org. Hudson Institute of Mineralogy, accessed June 23, 2019 .
  12. ↑ Kosva massif, Karpinsk, Sverdlovsk Oblast, Russiaa. In: mindat.org. Hudson Institute of Mineralogy, accessed June 23, 2019 .
  13. ^ Hadley Rille meteorite, Apollo 15 landing site area, Palus Putredinis, Mare Imbrium, The Moon. In: mindat.org. Hudson Institute of Mineralogy, accessed June 23, 2019 .