Stibiopalladinite
- Allopaladium
- Eugenesit
Stibiopalladinit, outdated also known as Allopaladium or Eugenesit, is a rarely occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the hexagonal crystal system with the composition Pd5Sb2, is so chemically seen a palladium - stibnite.
Stibiopalladinit is opaque in every shape and developed only microscopic crystals to about 200 microns in size with hexagonal, tafeligem habit and strong metallic luster. Usually he can be found, however, in the form of rounded grains and coarse, intergrown with Sperrylite aggregates of silver-white to steel-gray color with pink stitch ( in polished areas also yellowish white).
Etymology and history
The mineral was HR 1927 by Adam in the type locality, the found Tweefontein farm in the Bushveld complex in South Africa. He named it after the composition of the elements palladium and antimony (Latin stibium ). Adam appointed as the composition of the mineral initially on Pd3Sb, in the research of Mertieit, George A. Desborough, however, the correct composition Pd5Sb2 fixed.
Classification
In the classification by Strunz Stibiopalladinit is counted among the alloys and alloy- like compounds, a subset of the sulfides and sulfosalts. After the 8th edition forms a group together with Arsenopalladinit, Atheneit, Genkinit, Itoigawait, Majakit, Menshikovit, Mertieit -I, Mertieit -II, Palladoarsenid, Palladobismutoarsenid, Palladodymit, Polkanovit, Rhodarsenid, Stillwaterit, Ungavait and Vincentit. In the 9th edition, it forms its own sub-group of compounds of semi-metals with platinum - group elements (PGE ).
In the classification by Dana it forms with Palarstanid a subset of the sulfides, selenides and tellurides with the composition AmBn Xp, with (m n): p = 5:2.
Education and Locations
Stibiopalladinit is a rare component of platinum deposits. It is associated with Braggit, cooperite, Mertieit -II, Sperrylit, platinum - iron-copper [ nickel ] alloys, Genkinit, Platarsit, chromite, chalcopyrite, pentlandite, pyrrhotite, Geversit, gold and Violarit.
It is known a number of localities of the mineral. These include, in addition to the type locality Abberode and Zorge in the Harz ( Germany ), Goodnews Bay in the U.S. state of Alaska, Lydenburg and other localities in South Africa, Chocó in Colombia, Norilsk and Zlatoust in Russia, Lac des Iles in the Canadian province of Ontario.
Crystal structure
Stibiopalladinit crystallizes in the hexagonal crystal system in space group P63cm ( Raumgruppen-Nr. 185 ) with the lattice parameters a = 7.61 Å and c = 14.21 Å and 6 formula units per unit cell.