Awaruit

from Wikipedia, the free encyclopedia
Awaruit
Awaruite-186583.jpg
Awaruit from Josephine Creek, Josephine County , Oregon, United States (size: 2.2 cm 1.1 × 0.9 cm)
General and classification
chemical formula FeNi 3
Mineral class
(and possibly department) 		Elements (including natural alloys or intermetallic compounds as well as carbides, nitrides, phosphides and silicides)
System no. to Strunz
and to Dana 		1.AE.20 ( 8th edition : I / A.08)
01.01.11.04
Crystallographic Data
Crystal system cubic
Crystal class ; symbol cubic hexakisoctahedral; 4 / m  3  2 / m
Space group Pm 3 m (No. 221)Template: room group / 221
Lattice parameters a  = 3.59  Å
Formula units Z  = 1
Physical Properties
Mohs hardness 5.5 to 6 (VHN 50 = 265 to 380)
Density (g / cm 3 ) measured: 7.8 to 8.6; calculated:
Cleavage is missing
colour silver-white, gray-white
Line color light gray
transparency opaque
shine Metallic luster

Awaruit is a rather seldom occurring mineral from the mineral class of the "elements" (including natural alloys or intermetallic compounds as well as carbides, nitrides, phosphides and silicides) with the chemical composition FeNi 3 and thus belongs to the natural iron-nickel alloys .

Awaruit crystallizes in the cubic crystal system and is mostly found in river soaps in the form of pebbles, grains or flakes. The mineral rarely develops crystals up to four millimeters in length.

Etymology and history

Awaruit got its name wrongly after the river Awarua River or Awarua Bay , which are located in the West Coast region on the South Island of New Zealand . However, the mineral was never found there, but for the first time in the alluvial sands of the Gorge River and later also "in situ" (at the point of origin) in the serpentinite from the same valley. The analysis and first description was carried out in 1885 by William Skey .

Type material of the mineral is listed in the Geological Survey of New Zealand in Lower Hutt (North Island) under catalog no. P21969 kept.

classification

In the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the Awaruit belonged to the mineral class of "elements including natural alloys or intermetallic compounds as well as carbides, nitrides, phosphides and silicides" and there to the department of "metals and intermetallic alloys ( without semimetals) ”, where together with Jedwabit , solid nickel , taenite and tetrataenite, he formed the“ nickel series ” I / A.08 .

The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also assigns the Awaruit to the department of "Metals and Intermetallic Compounds". However, this is further subdivided according to the membership of the metals involved in certain element families, so that the mineral can be found in the sub-section "Iron-Chromium Family" according to its composition, where it is the only member of the unnamed group 1.AE. 20 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Awaruit to the class of "elements" and there to the department of the same name. Here it is in the " iron-nickel group " with system no. 01.01.11 to be found in the subsection "Elements: metallic elements other than the platinum group".

Crystal structure

Awaruit crystallizes cubically in the space group Pm 3 m (space group no. 221) with the lattice parameter a  = 3.59  Å and one formula units per unit cell . Template: room group / 221

Education and Locations

Awaruit is predominantly alluvial soaps - deposits discovered, but is originally from serpentinized peridotites and ophiolites . It is also rarely found in meteorites . The accompanying minerals in soaps include gold and magnetite ; in peridotites copper , heazlewoodite , pentlandite , violarite , chromite and millerite and in meteorites mainly kamacite , allabogdanite , schreiberite and graphite .

As a rather rare mineral formation, Awaruit can sometimes be abundant at various sites, but overall it is not very common. So far (as of 2016) around 150 sites are known for Awaruit worldwide. In New Zealand, the mineral was discovered in addition to its type locality Gorge River on the South Island on the rivers Cascade River , Hope River and Jerry River as well as in the rocks of Red Mountain and on the North Island in the Mokoia meteorite in the Taranaki region .

In Austria, Awaruit was found in a serpentinite quarry near Griesserhof in the area around Friesach and Hüttenberg in Carinthia and in Gams near Hieflau and the municipality of Kraubath an der Mur in Styria.

In Switzerland, the mineral is known to date from the serpentinites from the Tot Alp near Davos , from Quadrada in Val Poschiavo in the canton of Graubünden, from nickel-containing peridotites in Val Boschetto near Palagnedra in the canton of Ticino and the serpentinites of the Riffel Alp near Zermatt in the canton of Valais.

Other locations include the Antarctic (Meteorite Belgica 7904), Argentina (meteorites and serpentinites), Ethiopia (chromitites), Australia (serpentinite deposits), Brazil (meteorite), Australia (soaps, serpentinites), China (Cu-Ni deposits , Ophiolites, meteorites), Costa Rica, Dominican Republic (serpentinites), Finland, France (mainly serpentinites), Greece (ophiolites, serpentinites), Greenland ( Cape York meteorites ), India (ultramafit, meteorites), Indonesia, Italy (soaps, Serpentinite, Meteorite), Jamaica, Japan, Cuba (Chromitite), Morocco, Mexico ( Allende Meteorite ), New Caledonia, Norway (Serpentinite), Oman (Lunar Meteorite Dhofar 925), Pakistan (Serpentinite), Poland ( Morasko Meteorite ), Romania , Russia (Ni deposits, meteorites), Saudi Arabia (South Dahna meteorite), Sweden (Mn-Fe deposit Långban ), Zimbabwe (soaps), Slovakia (serpentinites), South Africa, Trinidad and Tobago (serpentinites) , Turkey (Ophiolithe, Chr omitite), Ukraine ( Krymka meteorite ), Hungary (Kaba meteorite), the United Kingdom and the United States of America.

Awaruit was also found in rock samples from the moon , more precisely from the Fra Mauro crater , along with other minerals.


See also

literature

  • W. Skey: On a new mineral (awaruite) from Barn Bay. Transactions and Proceedings of the New Zealand Institute, Volume 18 (1885), pp. 401-402 ( PDF 133.9 kB )
  • Paul Ramdohr : About Josephinit, Awaruit, Souesit, their properties, origin and Paragenesis . In: Mineralogical Magazine . tape 29 , 1950, pp. 374–394 ( rruff.info [PDF; 1.6 MB ]).
  • KA Rodgers, MH Hey: On the type locality and other occurrences of awaruite (FeNi3) in Westland, New Zealand . In: Mineralogical Magazine . tape 43 , 1980, pp. 647–650 ( rruff.info [PDF; 271 kB ]).

Web links

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

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.  42 .
  2. ↑ a b 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. ^ KA Rodgers, MH Hey: On the type locality and other occurrences of awaruite (FeNi3) in Westland, New Zealand . In: Mineralogical Magazine . tape 43 , 1980, pp. 647–650 ( rruff.info [PDF; 271 kB ]).
  4. ↑ Awaruite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 59 kB )
  5. ↑ Mindat - Number of localities for Awaruite
  6. ↑ Find location list for Awaruit at the Mineralienatlas and at Mindat
  7. ^ Mindat - type locality Fra Mauro Base (Apollo 14 landing site), Fra Mauro Highlands, The Moon