Erlichmanit

from Wikipedia, the free encyclopedia
Erlichmanit
General and classification
other names

IMA 1970-048

chemical formula OsS 2
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.EB.05a
02.12.01.16
Crystallographic Data
Crystal system cubic
Crystal class ; symbol cubic-disdodecahedral; 2 / m  3
Space group Pa 3 (No. 205)Template: room group / 205
Lattice parameters a  = 5.62  Å
Formula units Z  = 4
Physical Properties
Mohs hardness 7 to 7.5 ( VHN 100  = 1730–1950 kg / mm 2 )
Density (g / cm 3 ) measured: 8.28; calculated: 9.59
Cleavage not defined
colour gray to off-white
Line color not defined
transparency opaque (opaque)
shine Metallic luster

Erlichmanite is a rather seldom occurring mineral from the mineral class of " sulfides and sulfosalts " with the idealized chemical composition OsS 2 and thus, chemically speaking, osmium disulfide .

Erlichmanit crystallizes in the cubic crystal system and is usually found in the form of tiny grains (20 microns) in platinum - iron - alloys ( Ferro platinum ), platinum nuggets or as inclusions in chromite . Rounded pyritohedral crystals up to a millimeter in size are also rarely found . The mineral is in any form opaque ( opaque ) and displays on the surfaces of gray to gray white grains have a metallic luster .

Etymology and history

As early as 1928, the Norwegian mineralogy professor Ivar Oftedal (1894–1976) synthetically produced RuS 2 , AuSb 2 and MnTe 2 in addition to osmium disulfide (OsS 2 ) in order to analyze the crystal structure of these compounds of the pyrite type.

Natural mineral formation Erlichmanit was first in the MacIntosh mine , a precious metal - soap about half a kilometer north of Willow Creek in the Klamath Mountains found in Humboldt County in the US state of California. The first description was in 1971 by Kenneth G. Snetsinger. He named the mineral after the microprobe analyst of the Department Planetology in the Ames Research Center of NASA Jozef Erlichman (1935-) for his achievements in the analysis and identification of several new minerals - including sinoite , niningerite , Brezinait , Yagiit and armalcolite  - to honor .

The type material of the mineral is stored in the Mineralogical Collection of Stanford University in California under catalog no. 51965 and the National Museum of Natural History in Washington, DC (USA) under catalog no. 123914 kept.

To compare the chemical composition of Erlichmanit, Dr. Joachim Ottemann provided a sample from Western Ethiopia , which should also contain the new mineral Roseit (OsS), first described in 1967 by Ottemann and Stylianos-Savvas Augustithis . The material provided did not contain osmium monosulfide, although this phase could be present in other samples from the Ethiopian region. However, due to insufficient data, Ottemann and Augusthitis themselves doubted whether the assignment of the name Roseit could be justified, especially since the same name had been used by Dana since 1879 for a vermiculite-like and the name Rosit since 1840 for a pinite-like pseudomorphosis . In 1971 the name Roseit was rejected (discredited) by the IMA / CNMNC with a majority of over 60% of the commission.

classification

The erlichmanite is not yet listed in the outdated 8th edition of Strunz's mineral classification . Only in the Lapis mineral directory according to 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 , was the mineral given the system and mineral number. II / D.17-110 . In the “Lapis system” this corresponds to the class of “sulfides and sulfosalts” and there the section “sulfides with [the molar ratio] metal: S, Se, Te <1: 1”, where Erlichmanite together with aurostibite , fukuchilite , villamanínite , cattierite , Changchengit , Dzharkenit , Geversit , Hauerit , Insizwait , Krutaite , Laurit , Maslovit , Mayingit , Michenerit , Padmait , Penroseite , pyrite , Sperrylith , Testibiopalladit , Trogtalit and Vaesit the "pyrite group" formed (as 2018).

The 9th edition of Strunz's mineral systematics, valid since 2001 and updated by the International Mineralogical Association (IMA) until 2009, classifies the Erlichmanite in the section of "Metal sulfides with M: S ≤ 1: 2". This is further subdivided according to the exact molar ratio and the predominant metals in the compound, so that the mineral can be found according to its composition in the sub-section "M: S = 1: 2, with Fe, Co, Ni, PGE etc.", where it together with Aurostibit, cattierite, Dzharkenit, Fukuchilit, Gaotaiit , Geversit, Hauerit, Insizwait, Iridisit , Krutaite, Laurit, Penroseite, pyrite, Sperrylith, Trogtalit, Vaesit and Villamanínit the "pyrite group" with the system number. 2.EB.05a forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Erlichmanite to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here it is also in the "pyrite group (isometric: Pa 3 )" with the system no. 02.12.01 to be found within the subsection “ Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 1: 2 ”. Template: room group / 205

Chemism

According to the ideal (theoretical) composition of Erlichmanit (OsS 2 ), the mineral consists of 74.79% osmium and 25.21% sulfur .

However, the microprobe analysis of the type material from the MacIntosh mine revealed, in addition to 68% osmium and 25.3% sulfur, also low contents of 3.8% rhodium and 2.6% iridium as well as traces of palladium (0.5%) and ruthenium (0, 4%), which replace part of the osmium ( substitution , diadochy). The analyzed material from Oromia in western Ethiopia also had a similar composition with 64.3% osmium and 25.5% sulfur as well as 5.5% rhodium, 3.5% iridium, 0.6% palladium and 0.4% ruthenium .

Crystal structure

Erlichmanite crystallizes cubically in the pyrite structure in the space group Pa 3 (space group no. 205) with the lattice parameter a  = 5.62  Å and four formula units per unit cell . Template: room group / 205

properties

With a Mohs hardness of 7 to 7.5, which corresponds to a VHN of 1730–1950 kg / mm 2 with a test force of 100 g, Erlichmanite is one of the hard minerals. With the appropriate size, Erlichmanite would be able to scratch window glass, similar to the reference mineral quartz (hardness 7) .

The density of natural Erlichmanite is measured on average 8.28 g / cm 3 . The density calculated on the basis of the idealized crystal data is somewhat higher at 9.59 g / cm 3 .

Education and Locations

Erlichmanit found in platinum metal - soaps , probably from chromitithaltigen were formed and with ophiolite and other ultramafic were associated complexes by Alaskan type. As accompanying minerals may include Hollingworthit , Irarsit and Laurit , dignified platinum and osmium and natural Pt-Fe and many other platinum metal alloys and sulphides occur.

As a rather rare mineral formation, Erlichmanite can sometimes be abundant at various sites, but overall it is not very common. So far, almost 120 sites have been documented (as of 2020). Except at its type locality , the MacIntosh Mine at Willow Creek, the mineral occurred in California only on the American River near Folsom in Sacramento County. Other well-known sites in the United States are the Ketchikan mining area in the Gateway Borough of the same name and the Bethel Census Area in Alaska, the East Boulder Mine in Sweet Grass County of Montana and near Nottingham Township in the State Line chromite mining district in Chester County of Pennsylvania.

In Austria, Erlichmanite has so far only been found in an ultramafit quarry with serpentinite near Kraubath an der Mur and in an unnamed chromite pit on Mitterberg near Sankt Stefan ob Leoben in Styria.

Other locations include Australia, Brazil, Bulgaria, China, Costa Rica, Ecuador, Finland, France, Greece, India, Indonesia, Japan, Canada, Kazakhstan, Colombia, Cuba, Madagascar, Mexico, Mongolia, New Zealand, Norway, in Oman, the Philippines, Russia, Sierra Leone, Slovakia, Spain, Scotland in the United Kingdom, South Africa, Turkey and Cyprus.

The only documented site of extraterrestrial origin is the meteorite Acfer 217 , which was found in 1991 in the Algerian part of the Sahara and in which, in addition to erlichmanite, ilmenite , irarsite , laurite , moncheit , pentlandite , sperrylite , spinel and troilite could be detected.

See also

literature

  • Ivar Oftedal: About the crystal structures of the compounds RuS 2 , OsS 2 , MnTe 2 and AuSb 2 . With an appendix on the lattice constant of pyrite . In: Journal of Physical Chemistry . tape 135 , 1928, pp. 291–299 ( rruff.info [PDF; 376 kB ; accessed on April 18, 2020]).
  • Kenneth G. Snetsinger: Erlichmanite (OsS 2 ), a new mineral . In: American Mineralogist . tape 56 , 1971, p. 1501–1506 (English, rruff.info [PDF; 400 kB ; accessed on April 18, 2020]).
  • Th. Stingl, B. Mueller, HD Lutz: Crystal structure refinement of osmium (II) disulfide . In: Journal of Crystallography . tape 202 , 1992, pp. 161–162 (English, rruff.info [PDF; 64 kB ; accessed on April 18, 2020]).
  • Paul Ramdohr : The ore minerals and their adhesions . 4th, revised and expanded edition. Akademie-Verlag, Berlin 1975, p. 879 .
  • 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. 118 .

Web links

Individual evidence

  1. ↑ a b c Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: March 2020. (PDF; 2.44 MB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, March 2020, accessed April 18, 2020 .
  2. ↑ 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.  104 (English).
  3. ↑ a b c 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 .
  4. ↑ a b c d e f g h Erlichmanite . 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; 64  kB ; accessed on April 18, 2020]).
  5. ↑ a b Erlichmanite. In: mindat.org. Hudson Institute of Mineralogy, accessed April 18, 2020 .
  6. ^ Helmut Schrätze , Karl-Ludwig Weiner : Mineralogie. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp.  321 .
  7. ↑ a b Ivar Oftedal: About the crystal structures of the compounds RuS 2 , OsS 2 , MnTe 2 and AuSb 2 . With an appendix on the lattice constant of pyrite . In: Journal of Physical Chemistry . tape 135 , 1928, pp. 291–299 ( rruff.info [PDF; 376 kB ; accessed on April 18, 2020]).
  8. ^ A b Michael Fleischer : New Mineral Names . In: The American Mineralogist . tape  52 , no. 9-10 , 1967, pp. 1579 (English, minsocam.org [PDF; 800 kB ; accessed on April 18, 2020]).
  9. ^ HJ Axon, CV Waine: International Mineralogical Association: Commission on New Minerals and Mineral Names . In: Mineralogical Magazine . tape 38 , no. 293 , 1971, p. 102–105 (English, rruff.info [PDF; 194 kB ; accessed on April 19, 2020]).
  10. ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF; 1.82 MB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed April 18, 2020 .
  11. ↑ Erlichmanit. In: Mineralienatlas Lexikon. Stefan Schorn u. a., accessed on April 18, 2020 .
  12. ↑ Localities for Erlichmanite. In: mindat.org. Hudson Institute of Mineralogy, accessed April 18, 2020 .
  13. ↑ Find location list for Erlichmanite in the Mineralienatlas and Mindat , accessed on April 18, 2020.
  14. ^ Meteoritical Bulletin Database - Acfer 217. In: lpi.usra.edu. Meteoritical Bulletin , accessed April 18, 2020 .
  15. ↑ ACFER 217 meteorites, Tamanghasset Province, Algeria. In: mindat.org. Hudson Institute of Mineralogy, accessed April 18, 2020 .