Stibiopalladinite

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Stibiopalladinite
Stibiopalladinite - Mineralogical Museum Bonn.jpg
Stibiopalladinite (bottom center, probably embedded in calcite) from Tilkerode ( Abberode ) in the Harz
General and classification
other names
  • Allopaladium
  • Eugenesite
chemical formula Pd 5 Sb 2
Mineral class
(and possibly department)
Sulfides and sulfosalts
System no. to Strunz
and to Dana
2.AC.20 ( 8th edition : II / A.05)
03/02/03/01
Crystallographic Data
Crystal system hexagonal
Crystal class ; symbol dihexagonal-pyramidal; 6 mm
Room group (no.) P 6 3 cm (No. 185)
Lattice parameters a  = 7.61  Å ; c  = 14.21 Å
Formula units Z  = 6
Twinning universal
Physical Properties
Mohs hardness 4 to 5
Density (g / cm 3 ) calculated: 10.8
Cleavage Please complete!
colour silvery white to steel gray with a pink tinge
Line color black
transparency opaque
shine Metallic luster

Stibiopalladinite obsolete as Allopaladium or Eugenesit known is a rarely occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the hexagonal crystal system with the composition Pd 5 Sb 2 , so it is chemically a palladium - antimonite .

Stibiopalladinite is opaque in every form and only develops microscopic crystals up to about 200 micrometers in size with a hexagonal, tabular habit and a strong metallic sheen . Mostly, however, it is found in the form of rounded grains and coarse aggregates, fused with sperrylite, from silver-white to steel-gray in color with a pinkish tinge (in polished areas also yellowish-white).

Etymology and history

The mineral was found in 1927 by HR Adam at its type locality , Tweefontein Farm in the Bushveld complex in South Africa . He named it after the elements it contained palladium and antimony (Latin stibium). Adam initially determined the composition of the mineral to be Pd 3 Sb, but while researching Mertieit, George A. Desborough found the correct composition Pd 5 Sb 2 .

classification

In the Strunz system , stibiopalladinite is one of the alloys and alloy-like compounds, a subgroup of sulfides and sulfosalts. After the 8th edition it forms a group together with arsenopalladinite , athenite , genenkinite , itoigawaite , mayakite , menshikovite , mertieit-I , mertieit-II , palladoarsenide , palladobismutoarsenide , palladodymite , polkanovite , rhodarsenide , stillwaterite , ungavaite and vincentite . In the 9th edition it forms its own subgroup of compounds of semimetals with platinum group elements (PGE).

In the systematics according to Dana , which is mainly used in the English-speaking world , with palarstanide it forms a subgroup of sulfides, selenides and tellurides with the composition A m B n X p , with (m + n): p = 5: 2.

Education and Locations

Stibiopalladinite is a rare component of platinum deposits. It is associated with braggite , cooperite , mertieite-II , sperrylite , platinum - iron - copper - [nickel] alloys, genenkinite , platarsite , chromite , chalcopyrite , pentlandite , pyrrhotite , geversite , gold and violarite .

A number of locations of the mineral are known. These include the type locality Abberode and Zorge in the Harz ( Germany ), Goodnews Bay in the US state of Alaska , Lydenburg and other sites in South Africa , Chocó in Colombia , Norilsk and Slatoust in Russia , Lac des Îles in the Canadian province of Ontario .

Crystal structure

Stibiopalladinite crystallizes in the hexagonal crystal system in the space group P 6 3 cm (space group no. 185) with the lattice parameters a = 7.61  Å and c = 14.21 Å as well as 6 formula units per unit cell .

See also

Individual evidence

  1. ^ A b c Hugo Strunz , Ernest H. Nickel: Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 60 .
  2. George A. Desborough, JJ Finney, BF Leonard: Mertieite, a new palladium mineral from Goodnews Bay, Alaska. In: American Mineralogist. 1973, 58, pp. 1-10 ( minsocam.org PDF).
  3. ^ New Dana Classification of Sulfide Minerals.

literature

  • Helmut Schrätze, Karl-Ludwig Weiner: Mineralogy. A textbook on a systematic basis . de Gruyter, Berlin / New York 1981, ISBN 3-11-006823-0 , p. 117 .
  • Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 415 (first edition: 1891).
  • Stibiopalladinite. In: Anthony et al .: Handbook of Mineralogy. 1990, 1, 101 ( handbookofmineralogy.org PDF).
  • Louis J. Cabri, T. Tzong: Stibiopalladinite from the type locality. In: American Mineralogist. 61, 1976, pp. 1249-1254 ( minsocam.org PDF).

Web links

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