Polkanovite
| Polkanovite | |
|---|---|
| General and classification | |
| other names |
IMA 1997-030 |
| chemical formula | Rh 12 As 7 |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.AC.30 ( 8th edition : II / A.05) 04/02/20/01 |
| Crystallographic Data | |
| Crystal system | hexagonal |
| Crystal class ; symbol | hexagonal dipyramidal; 6 / m |
| Room group (no.) | P 6 3 / m (No. 176) |
| Lattice parameters | a = 9.297 Å ; c = 3.657 Å |
| Formula units | Z = 1 |
| Physical Properties | |
| Mohs hardness | not defined (VHN 40 : 399–422 kg / mm 2 ) |
| Density (g / cm 3 ) | calculated: 10.20 |
| Cleavage | not observed |
| colour | brownish gray |
| Line color | Please complete |
| transparency | opaque |
| shine | Metallic luster |
Polkanovit is a very rare mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the hexagonal crystal system with the chemical composition Rh 12 As 7 .
Polkanovite is opaque in every form and has so far only been found in the form of massive aggregates from brownish-gray to gray, metallic shimmering color.
Etymology and history
Polkanovite was first discovered on the Miass River in the Russian Oblast of Chelyabinsk and scientifically described by SN Britvin, NS Rudashevsky, А. N. Bogdanova and D. К. Shcherbachov, who named the mineral after Yuri Aleksandrovich Polkanov (* 1935) to honor his contributions to the study of mineralogy and ore deposits of the Crimean peninsula , especially in relation to the soap deposits.
classification
In the now outdated, but still in use 8th edition of the mineral classification according to Strunz , the Polkanovite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "alloys and alloy-like compounds", where together with arsenopalladinite , athenite , genenkinite , isomertieite , Mertieit-I , Mertieit-II , Miessiit ( IMA 2006-013 ), Majakit , Menshikovit , Naldrettit , Palladoarsenid , Palladobismutoarsenid , Palladodymit , Rhodarsenid , stibiopalladinite , Stillwaterit , Ungavait and Vincentit the "Arsenopalladinit group" with the system number. II / A.05 .
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 Polkanovite to the class of "sulfides and sulfosalts (sulfides, selenides, tellurides, arsenides, antimonides, bismuthides, sulfarsenites, sulfantimonites" , Sulfbismuthite) "and there in the section of" Alloys and alloy-like compounds ". However, this division is further subdivided according to the predominant metals or semi-metals in the compound, so that the mineral can be found according to its composition in the sub-division "Compounds of semi-metals with platinum group elements (PGE)", where it is the only member forms the unnamed group 2.AC.30 .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns Polkanovite to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here he is the only member of the unnamed group 04/02/2020 within the subsection “ Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 2: 1 ”.
Education and Locations
Polkanovite is found as a residue in soap deposits , mostly grown together with isoferroplatinum and tulameenite and as an inclusion in ruthenium .
Apart from its type locality Miass in Russia, the mineral could so far (as of 2012) only be found near Qusum in China.
Crystal structure
Polkanovit crystallizes hexagonally in the space group P 6 3 / m (space group no. 176) with the lattice parameters a = 9.297 Å and c = 3.657 Å and one formula unit per unit cell .
See also
literature
- SN Britvin, NS Rudashevsky, А. N. Bogdanova, D. К. Shcherbachov: Polkanovite Rh 12 As 7 - the new mineral from a placer at the Miass River (the South Urals) , in: Zapiski Vserossijskogo Mineralogicheskogo Obshchestva , Volume 127 (1998), Chapter 2, pp. 60-62 ( PDF 173.4 kB )
Web links
- Mineral Atlas: Polkanovit (Wiki)
Individual evidence
- ^ A b 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. 61 .
- ↑ a b c Webmineral - Polkanovite
- ↑ a b c American-Mineralogist-Crystal-Structure-Database - Polkanovite (1985)
- ^ Mindat - Polkanovite