Palladobismuto arsenide
| Palladobismuto arsenide | |
|---|---|
| General and classification | |
| chemical formula | Pd 2 (As, Bi) |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.AC.25 ( 8th edition : II / A.05) 2.4.15.1 |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | mm 2 or mmm |
| Space group | Pmcn or P2 1 cn |
| Lattice parameters | a = 7.504 Å ; b = 18.884 Å; c = 6.841 Å Please complete the source as an individual reference |
| Formula units | Z = 20 Please complete the source as an individual reference |
| Physical Properties | |
| Mohs hardness | 5 |
| Density (g / cm 3 ) | 10.8 |
| Cleavage | Please complete |
| colour | silver-white |
| Line color | Please complete |
| transparency | opaque |
| shine | metallic |
Palladobismuto arsenide is a very rarely occurring mineral from the mineral class of sulfides and sulfosalts . It crystallizes in the orthorhombic crystal system with the chemical composition Pd 2 (As, Bi) and forms irregularly shaped grains up to 165 μm in size with a creamy-white color.
Etymology and history
The mineral was discovered in 1976 by LJ Cabri, TT Chen, JW Stewart and JHG Laflamme in its type locality , the Stillwater Complex in the US state of Montana . It is named after the elements palladium , bismuth and arsenic it contains.
classification
In the Strunz system , palladobismuto arsenide is one of the alloys and alloy-like compounds, a sub-group of sulfides and sulfosalts. After the 8th edition , it forms a group together with arsenopalladinite , athenite , genenkinite , itoigawaite , mayakite , menshikovite , mertieite-I , mertieite-II , palladoarsenide , palladodymite , polkanovite , rhodarsenide , stibiopalladinite , stillwaterite , ungavaite and vincentite . In the 9th edition it forms with mayakite, naldrettite , pallado arsenide, palladodymite and rhod arsenide a subgroup of the compounds of semi-metals with platinum group elements (PGE).
In the systematics according to Dana , which is mainly used in the English-speaking world , it forms its own subgroup of sulfides, selenides and tellurides with the composition A m B n X p , with (m + n): p = 2: 1.
Education and Locations
Palladobismuto arsenide is formed in heavy metal concentrates. It is associated with pallado arsenide and calcite .
Only a few locations are known of the very rare mineral. In addition to its type locality, only one other site is known so far on the Kola Peninsula in Russia .
Crystal structure
Palladobismutoarsenide crystallizes in the orthorhombic crystal system in the space group Pmcn or P2 1 cn with the lattice parameters a = 7.504 Å , b = 18.884 Å and c = 6.841 Å as well as 20 formula units per unit cell .
See also
Individual evidence
literature
- Palladobismuth arsenide (PDF; 61 kB) in: Anthony et al .: Handbook of Mineralogy , 1990, 1, 101.