Osbornite

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Osbornite
General and classification
chemical formula TiN
Mineral class
(and possibly department) 		Elements (including natural alloys, intermetallic compounds, carbides, nitrides, phosphides and silicides)
System no. to Strunz
and to Dana 		1.BC.15 ( 8th edition : I / A.10)
01.01.19.01
Crystallographic Data
Crystal system cubic
Crystal class ; symbol cubic hexakisoctahedral; 4 / m  3  2 / m
Space group Fm 3 m (No. 225)Template: room group / 225
Lattice parameters a  = 4.24  Å
Formula units Z  = 4
Physical Properties
Mohs hardness 8 to 9 ( VHN 20 = 1372)
Density (g / cm 3 ) calculated: [5.38]
Cleavage Please complete!
Break ; Tenacity brittle
colour golden yellow
Line color not defined
transparency opaque
shine Metallic luster

Osbornite is a very seldom occurring mineral from the mineral class of the "elements (including natural alloys, intermetallic compounds, carbides, nitrides, phosphides and silicides)" with the chemical composition TiN and is therefore chemically titanium nitride .

Osbornite crystallizes in the cubic crystal system , but has so far only been discovered in the form of microscopic, octahedral crystals up to about 0.1 mm in size. The mineral is opaque in every form and shows a strong metallic luster on the surfaces of the golden yellow crystals .

Osbornite is a typical meteorite mineral , of which only two purely terrestrial sites are known so far (as of 2017).

Etymology and history

Osbornite was first discovered in the Bustee meteorite , which fell in 1852 about 45 miles west of Gorakhpur near the Bustee Station in the Basti district of the northern Indian state of Uttar Pradesh . The mineral was described in 1870 by Mervyn Herbert Nevil Story-Maskelyne (1823-1911), who named it after George Osborne, who discovered the meteorite and sent it to London .

Type material, i.e. mineral samples from its type locality Bustee, is in the Natural History Museum in London under catalog no. 32100 kept.

classification

Already in the outdated but still partially in use 8th edition of the mineral classification by Strunz of osbornite belonged to the mineral class of "elements" and then to the Department of "metals and intermetallic alloys (semimetals)" where he collaborated with Carlsbergit , Nierit , Roaldit , sinoite and Siderazot the unnamed group I / A.10 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 osbornite in the more finely subdivided section of "Metallic carbon, nitrogen and phosphorus compounds". This is also further subdivided according to the corresponding substance groups, so that the mineral can be found in the sub-section "Nitrides" according to its composition, where it is only the "osbornite group" with the system no. 1.BC.15 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the osbornite to the class and department of the same name of "elements". Here it is together with khamrabaevite , niobocarbide and tantalum carbide in the " osbornite group, carbide and nitride " with the system no. 01.01.19 to be found in the subsection "Elements: Metallic elements other than the platinum group".

Crystal structure

Osbornite crystallizes cubically in the space group Fm 3 m (space group no. 225) with the lattice parameter a  = 4.24  Å and 4 formula units per unit cell . The crystal structure is similar to that of sodium chloride . Template: room group / 225

Education and Locations

In its type locality, the achondrite bustee , which fell in India , osbornite was found embedded in the mineral oldhamite, which was also first discovered in the bustee meteorite, and associated with diopside, among other things .

Furthermore, Osborn has so far (as of 2017) been detected in the following meteorites:

Outside the earth, osbornite was also found in mineral samples from the coma of comet 81P / Wild 2 .

The only purely terrestrial locations for osbornite to date are an ore body in the Luobusha Mine ( Luobusa Mine ) in the Qusum district in Tibet and an unspecified location in the Brazilian state of Bahia .

See also

literature

  • FA Bannister: Osbornite, meteoritic titanium nitride . In: Mineralogical Magazine . tape 26 , 1941, pp. 36–44 ( rruff.info [PDF; 415 kB ; accessed on December 27, 2017]).

Web links

Individual evidence

  1. ↑ 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.  49 .
  2. ↑ 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. ↑ a b c Osbornite . 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; 59  kB ; accessed on December 27, 2017]).
  4. ↑ Mindat - Osbornite (English)
  5. ↑ Gerald Joseph Home McCall, AJ Bowden, Richard John Howarth (Eds.): The History of Meteoritics and Key Meteorite Collections: Fireballs, Falls and Finds. Special Publication 256 . Geological Society of London, London 2006, ISBN 978-1-86239-194-9 , pp. 154–156 ( limited preview in Google Book search).
  6. ↑ a b c List of places where osbornite was found in the Mineralienatlas and Mindat
  7. ^ Meteoritical Bulletin Database of the Meteoritical Society